This document discusses microbial culture techniques and applications. It begins by introducing the importance of microbes and how microbial cultures are used industrially to produce chemicals like antibiotics, alcohols, and proteins. It then describes the basic requirements for microbial culture, including nutrients, culture procedures like sterilization and aeration, and equipment used like flasks, shakers, and fermentors. The key aspects covered are the nutrient requirements for microbial growth, various culture techniques and factors that affect microbial growth, and equipment used for microbial cultivation at different scales.
The document describes the process for producing enzymes and antibiotics through fermentation. Key steps include identifying an optimal microorganism, growing starter cultures in seed tanks, conducting large-scale fermentation, isolating and purifying the target compound, refining it for end use, and implementing quality control measures throughout production.
Microbes, or microscopic organisms, are widely used in large-scale industrial processes. Microbes can be used to create biofertilizers or to reduce metal pollutants. Microbes can also be used to produce certain non-microbial products, such as the diabetes medication insulin, vaccines, etc. These slides will give insights into uses of microbes in production of enzymes, antibiotics, beverages, vitamins, vaccines, probiotics, etc
Fermentation is a process where microbes such as bacteria and fungi convert carbohydrates into products like alcohols, organic acids, or gases. It is an ancient technique used in foods and beverages. Modern industrial fermentation uses controlled bioreactors and genetically engineered microbes to efficiently produce metabolites. There are three main types of industrial fermentation processes - batch, continuous, and fed-batch - which differ in how nutrients are added and removed from the fermentation vessel over time to influence microbial growth phases and maximize metabolite production.
This document discusses the key concepts and goals of industrial microbiology and biotechnology. It explains that these fields involve using microorganisms to achieve specific aims, such as producing antibiotics, amino acids, organic acids, and other useful products. The document outlines various techniques for genetically manipulating microorganisms, preserving strains, growing microbes in controlled environments, and utilizing microbial communities in natural environments for applications like biodegradation. The overall aim is to discuss how microbes can be utilized and manipulated for industrial and biotechnological processes.
Applications of environmental microbiology in industriesAbhishek Rajput
The document discusses the industrial uses of microbes such as fungi, algae, bacteria, protozoa and viruses. It provides examples of how fungi are used in brewing, winemaking and cheese production. Algae have industrial uses as fertilizers, feed and in producing biodiesel, bioethanol and biobutanol. Bacteria are used in mining, materials processing, energy production and manufacturing drugs and polymers. Protozoa aid soil fertility and wastewater treatment. Viruses are being studied for uses including cancer treatment and pest control. The document also examines detection of microbes in water and biosensing technologies.
The document discusses different types of culture media used for industrial fermentation. There are natural/crude media which use biological sources like tissue extracts. Synthetic/artificial media use defined chemical compounds and are grouped into serum-containing, serum-free, chemically defined, and protein-free. Enrichment media add specific growth substances to basal media. Selective media contain antimicrobials or dyes to inhibit unwanted microorganisms and support growth of target organisms. Examples given are EMB agar and Mannitol Salt agar.
The document describes the process for producing enzymes and antibiotics through fermentation. Key steps include identifying an optimal microorganism, growing starter cultures in seed tanks, conducting large-scale fermentation, isolating and purifying the target compound, refining it for end use, and implementing quality control measures throughout production.
Microbes, or microscopic organisms, are widely used in large-scale industrial processes. Microbes can be used to create biofertilizers or to reduce metal pollutants. Microbes can also be used to produce certain non-microbial products, such as the diabetes medication insulin, vaccines, etc. These slides will give insights into uses of microbes in production of enzymes, antibiotics, beverages, vitamins, vaccines, probiotics, etc
Fermentation is a process where microbes such as bacteria and fungi convert carbohydrates into products like alcohols, organic acids, or gases. It is an ancient technique used in foods and beverages. Modern industrial fermentation uses controlled bioreactors and genetically engineered microbes to efficiently produce metabolites. There are three main types of industrial fermentation processes - batch, continuous, and fed-batch - which differ in how nutrients are added and removed from the fermentation vessel over time to influence microbial growth phases and maximize metabolite production.
This document discusses the key concepts and goals of industrial microbiology and biotechnology. It explains that these fields involve using microorganisms to achieve specific aims, such as producing antibiotics, amino acids, organic acids, and other useful products. The document outlines various techniques for genetically manipulating microorganisms, preserving strains, growing microbes in controlled environments, and utilizing microbial communities in natural environments for applications like biodegradation. The overall aim is to discuss how microbes can be utilized and manipulated for industrial and biotechnological processes.
Applications of environmental microbiology in industriesAbhishek Rajput
The document discusses the industrial uses of microbes such as fungi, algae, bacteria, protozoa and viruses. It provides examples of how fungi are used in brewing, winemaking and cheese production. Algae have industrial uses as fertilizers, feed and in producing biodiesel, bioethanol and biobutanol. Bacteria are used in mining, materials processing, energy production and manufacturing drugs and polymers. Protozoa aid soil fertility and wastewater treatment. Viruses are being studied for uses including cancer treatment and pest control. The document also examines detection of microbes in water and biosensing technologies.
The document discusses different types of culture media used for industrial fermentation. There are natural/crude media which use biological sources like tissue extracts. Synthetic/artificial media use defined chemical compounds and are grouped into serum-containing, serum-free, chemically defined, and protein-free. Enrichment media add specific growth substances to basal media. Selective media contain antimicrobials or dyes to inhibit unwanted microorganisms and support growth of target organisms. Examples given are EMB agar and Mannitol Salt agar.
Fermentation, Fermentation Technology, what are fermentors, process associated in this techniques, basic structures and its designing, types of fermentors.
This document discusses the medical applications of fermentation technology. It begins with an introduction to fermentation and how microorganisms can be used to produce useful chemicals. It then discusses the types and stages of industrial fermentation processes. Some key applications of fermentation in medicine discussed include the production of insulin, vaccines, interferons, vitamin B12, enzymes, and antibiotics. Modern fermentation allows for mass production of these substances using genetically engineered microorganisms.
This PPT will provide the basic idea of Fermentation technology and it's use. The reference book is 'Pharmaceutical Biotechnology' by Giriraj Kulkarni.
The document discusses fermentors and bioreactors. It describes how fermentors are closed vessels used for large-scale fermentation processes to produce products like antibiotics, amino acids, and organic acids. The document outlines the key components of fermentors, including a water jacket, stirring paddles, and inputs and outputs for nutrients, products, and steam. It also discusses upstream processing like medium preparation and sterilization, inoculation, and the different types of fermentation systems like batch, continuous, and fed-batch culture. Downstream processing steps like product extraction, purification, and formulation are also summarized.
This document provides an overview of bioprocessing and industrial biotechnology. It discusses the history and milestones of the industry from ancient times to present. Key topics covered include major industrial fermentation products, stages of development from 1900 to today, microbial cell bioprocessing, scaling up processes from lab to production scale, and the types of bioreactors used to produce products from mammalian, plant, insect, algal and bacterial cells. The document also briefly outlines considerations for media composition, cultivation conditions, process optimization and control, and the future potential of industrial bioprocessing.
Industrial product derived from microbsAnbarasan D
Microbial biotechnology uses microbes to produce products and services of economic value through fermentation. Some key properties of useful microorganisms include being able to produce spores or be easily inoculated, grow rapidly at large scale in inexpensive media, and produce the desired product quickly without being pathogenic or difficult to genetically manipulate. Microbes are used industrially to produce beverages, antibiotics, organic acids, amino acids, enzymes, vitamins, organic solvents, single cell protein, steroids, pharmaceutical drugs, and dairy products. Common microorganisms used include yeasts, bacteria, actinomycetes and fungi.
This document discusses the importance of yeast in industrial microbiology. It begins by introducing industrial microbiology and describing microbes as ideal organisms for industrial processes due to their enzymes, metabolic activity, reproduction rate, and manipulability. It then discusses how yeast is commonly used in industries like food production, beverages, and baking. Specific examples are given of yeast being used to produce items like soy sauce, sour bread, and alcohol. The document concludes by noting the significance of yeast in food, beverage, medical, and chemical industries through various fermentation processes.
Industrial fermenters are used to grow cells on a large scale by carefully controlling the environment. They are made of stainless steel and can hold up to 200,000 liters. Nutrients are fed in through sterile pipes and conditions like temperature, pH, oxygen, and carbon dioxide levels are monitored electronically and automatically regulated. Fermenters require sterile conditions and cooling to control cell growth and regulate temperature increases from microbial activity that could kill the cells. Most fermentations are batch processes but some use continuous culture systems with steady nutrient input and waste removal.
Microbial enzymes are biological catalysts produced by microorganisms that are used for various biochemical reactions. There are two main types of enzymes - adaptive and constitutive. Enzymes can be produced via submerged culture or semisolid culture methods. Semisolid culture involves growing the enzyme-producing microorganism on the surface of a moistened solid substrate, while submerged culture uses fermentation equipment like tanks. Common microbes used in enzyme production include Aspergillus species. The production process involves isolation of microorganisms, strain development, inoculum preparation, and fermentation.
This document discusses bioprocessing and its relationship to biotechnology. It defines bioprocessing as using living cells or their components to produce desired products. Bioprocessing involves upstream processing to extract raw materials, fermentation to culture microorganisms and convert materials, and downstream processing to purify fermented products. The document also notes that bioprocessing is a type of bioengineering which applies engineering and life science principles to tissues, cells and molecules.
Traditional fermentation has been used in India for over 3,000 years to produce products like soma juice, sura (wine/beer), and curd. The process was discovered by observing changes in stored fruits and juices. Two main fermentation techniques that have developed are solid state fermentation and submerged fermentation. Solid state fermentation uses solid substrates and is suited for fungi, while submerged fermentation uses liquid substrates and is suited for bacteria. Both techniques have various industrial and medical applications.
Microbial fermentation involves microorganisms like yeast and bacteria breaking down substances and converting them into simpler products. Fermentation is used to produce foods and beverages like beer, wine, bread, and yogurt. The document discusses fermentation processes like the types of fermenters used, fermentation media composition, inoculation, and techniques. Some important fermentation products mentioned are ethanol, lactic acid, enzymes, and cheeses. Challenges in microbial fermentation can include bacterial, viral, and fungal contamination that reduce yields and productivity.
Fermentation is a process where microorganisms are grown on a large scale to produce commercial products. Important fermentation products include ethanol, glycerol, lactic acid, acetone, and butanol. Fermentations can occur on an industrial scale using large fermentors. There are three main types of fermentation: batch, continuous, and fed-batch. Fermentation has advantages like preserving and enriching foods, contributing to nutrition, and having low costs. However, it can also pose food safety risks if not properly controlled.
Enzymes are protein catalysts that speed up biochemical reactions without being consumed. They work by specifically binding to substrates and facilitating the formation of products. Enzyme activity is optimized at a certain temperature and pH for each enzyme and can be denatured by extremes of heat or pH. Biological washing powders and food processing use enzymes to break down targets like proteins, starch, and cell walls for cleaning or extraction purposes. Common industrial production of enzymes involves growing bacteria or fungi in large fermenters to secrete the enzymes.
This document provides an overview of bioprocess engineering. It defines a bioprocess as a process that uses living cells or their components to produce desired products. Bioprocess engineering deals with designing equipment and processes for producing items like pharmaceuticals, chemicals, and polymers using bioprocesses. The document then describes the major components of bioprocesses, including upstream processing, fermentation, and downstream processing. It provides examples of products produced through various bioprocesses.
This document discusses single cell proteins (SCP), which are dried cells of microorganisms that can be used as a dietary protein supplement. SCPs are produced using biomass as a raw material and various microorganisms like fungi, algae, and bacteria that are cultured on the biomass. The production involves selecting suitable microorganism strains, fermenting them, harvesting the cells, and processing them for use as a protein supplement in foods. SCPs have advantages like being a renewable source of protein but also have disadvantages like potentially high nucleic acid content.
New trends in fermentation technology - Using Algae as biomassSairam Sirigina
This document discusses new trends in fermentation technology and bioreactor development for bioethanol production from algae. It outlines limitations with existing bioethanol production methods and explores using algae as an alternative biomass. Different cultivation methods for algae are described, including open ponds, tubular photobioreactors, flat plate photobioreactors, and biofilm-based systems. Harvesting and dewatering techniques like flocculation and electrochemical processes are also covered. The document concludes with an overview of converting harvested algal biomass into bioethanol through drying, crushing, fermentation and distillation.
This document discusses the commercial production of enzymes. It begins by explaining that enzymes are protein molecules produced by living cells that catalyze biochemical reactions. It then discusses the major sources of commercial enzymes, including microbes, animals and plants. Microbial sources such as fungi and bacteria are preferred due to their ability to produce large quantities of enzymes economically. The document outlines methods for increasing microbial enzyme production, including regulating production conditions, using genetic engineering to transfer genes between organisms, and protein engineering to modify enzyme properties.
The document describes the process for producing enzymes and antibiotics through fermentation. Key steps include identifying an optimal microorganism, growing starter cultures in seed tanks, conducting large-scale fermentation, isolating and purifying the target compound, and performing quality control checks before distribution. Enzymes and antibiotics are valuable industrial products created through carefully controlled microbial growth and compound extraction processes.
The document summarizes shake flask optimization studies done to determine the best conditions for growth of Pichia pastoris culture. Media type (tryptone soya broth and nutrient broth), pH (ranging from 3.0 to 8.0), and inoculum percentage were optimized. Tryptone soya broth at pH 6.0 showed the highest optical density, indicating it is the optimum medium and pH for growth. Further fine tuning of pH in the range of 5.5-6.6 in tryptone soya broth identified pH 6.0 as providing the maximum growth of the Pichia pastoris culture.
Fermentation, Fermentation Technology, what are fermentors, process associated in this techniques, basic structures and its designing, types of fermentors.
This document discusses the medical applications of fermentation technology. It begins with an introduction to fermentation and how microorganisms can be used to produce useful chemicals. It then discusses the types and stages of industrial fermentation processes. Some key applications of fermentation in medicine discussed include the production of insulin, vaccines, interferons, vitamin B12, enzymes, and antibiotics. Modern fermentation allows for mass production of these substances using genetically engineered microorganisms.
This PPT will provide the basic idea of Fermentation technology and it's use. The reference book is 'Pharmaceutical Biotechnology' by Giriraj Kulkarni.
The document discusses fermentors and bioreactors. It describes how fermentors are closed vessels used for large-scale fermentation processes to produce products like antibiotics, amino acids, and organic acids. The document outlines the key components of fermentors, including a water jacket, stirring paddles, and inputs and outputs for nutrients, products, and steam. It also discusses upstream processing like medium preparation and sterilization, inoculation, and the different types of fermentation systems like batch, continuous, and fed-batch culture. Downstream processing steps like product extraction, purification, and formulation are also summarized.
This document provides an overview of bioprocessing and industrial biotechnology. It discusses the history and milestones of the industry from ancient times to present. Key topics covered include major industrial fermentation products, stages of development from 1900 to today, microbial cell bioprocessing, scaling up processes from lab to production scale, and the types of bioreactors used to produce products from mammalian, plant, insect, algal and bacterial cells. The document also briefly outlines considerations for media composition, cultivation conditions, process optimization and control, and the future potential of industrial bioprocessing.
Industrial product derived from microbsAnbarasan D
Microbial biotechnology uses microbes to produce products and services of economic value through fermentation. Some key properties of useful microorganisms include being able to produce spores or be easily inoculated, grow rapidly at large scale in inexpensive media, and produce the desired product quickly without being pathogenic or difficult to genetically manipulate. Microbes are used industrially to produce beverages, antibiotics, organic acids, amino acids, enzymes, vitamins, organic solvents, single cell protein, steroids, pharmaceutical drugs, and dairy products. Common microorganisms used include yeasts, bacteria, actinomycetes and fungi.
This document discusses the importance of yeast in industrial microbiology. It begins by introducing industrial microbiology and describing microbes as ideal organisms for industrial processes due to their enzymes, metabolic activity, reproduction rate, and manipulability. It then discusses how yeast is commonly used in industries like food production, beverages, and baking. Specific examples are given of yeast being used to produce items like soy sauce, sour bread, and alcohol. The document concludes by noting the significance of yeast in food, beverage, medical, and chemical industries through various fermentation processes.
Industrial fermenters are used to grow cells on a large scale by carefully controlling the environment. They are made of stainless steel and can hold up to 200,000 liters. Nutrients are fed in through sterile pipes and conditions like temperature, pH, oxygen, and carbon dioxide levels are monitored electronically and automatically regulated. Fermenters require sterile conditions and cooling to control cell growth and regulate temperature increases from microbial activity that could kill the cells. Most fermentations are batch processes but some use continuous culture systems with steady nutrient input and waste removal.
Microbial enzymes are biological catalysts produced by microorganisms that are used for various biochemical reactions. There are two main types of enzymes - adaptive and constitutive. Enzymes can be produced via submerged culture or semisolid culture methods. Semisolid culture involves growing the enzyme-producing microorganism on the surface of a moistened solid substrate, while submerged culture uses fermentation equipment like tanks. Common microbes used in enzyme production include Aspergillus species. The production process involves isolation of microorganisms, strain development, inoculum preparation, and fermentation.
This document discusses bioprocessing and its relationship to biotechnology. It defines bioprocessing as using living cells or their components to produce desired products. Bioprocessing involves upstream processing to extract raw materials, fermentation to culture microorganisms and convert materials, and downstream processing to purify fermented products. The document also notes that bioprocessing is a type of bioengineering which applies engineering and life science principles to tissues, cells and molecules.
Traditional fermentation has been used in India for over 3,000 years to produce products like soma juice, sura (wine/beer), and curd. The process was discovered by observing changes in stored fruits and juices. Two main fermentation techniques that have developed are solid state fermentation and submerged fermentation. Solid state fermentation uses solid substrates and is suited for fungi, while submerged fermentation uses liquid substrates and is suited for bacteria. Both techniques have various industrial and medical applications.
Microbial fermentation involves microorganisms like yeast and bacteria breaking down substances and converting them into simpler products. Fermentation is used to produce foods and beverages like beer, wine, bread, and yogurt. The document discusses fermentation processes like the types of fermenters used, fermentation media composition, inoculation, and techniques. Some important fermentation products mentioned are ethanol, lactic acid, enzymes, and cheeses. Challenges in microbial fermentation can include bacterial, viral, and fungal contamination that reduce yields and productivity.
Fermentation is a process where microorganisms are grown on a large scale to produce commercial products. Important fermentation products include ethanol, glycerol, lactic acid, acetone, and butanol. Fermentations can occur on an industrial scale using large fermentors. There are three main types of fermentation: batch, continuous, and fed-batch. Fermentation has advantages like preserving and enriching foods, contributing to nutrition, and having low costs. However, it can also pose food safety risks if not properly controlled.
Enzymes are protein catalysts that speed up biochemical reactions without being consumed. They work by specifically binding to substrates and facilitating the formation of products. Enzyme activity is optimized at a certain temperature and pH for each enzyme and can be denatured by extremes of heat or pH. Biological washing powders and food processing use enzymes to break down targets like proteins, starch, and cell walls for cleaning or extraction purposes. Common industrial production of enzymes involves growing bacteria or fungi in large fermenters to secrete the enzymes.
This document provides an overview of bioprocess engineering. It defines a bioprocess as a process that uses living cells or their components to produce desired products. Bioprocess engineering deals with designing equipment and processes for producing items like pharmaceuticals, chemicals, and polymers using bioprocesses. The document then describes the major components of bioprocesses, including upstream processing, fermentation, and downstream processing. It provides examples of products produced through various bioprocesses.
This document discusses single cell proteins (SCP), which are dried cells of microorganisms that can be used as a dietary protein supplement. SCPs are produced using biomass as a raw material and various microorganisms like fungi, algae, and bacteria that are cultured on the biomass. The production involves selecting suitable microorganism strains, fermenting them, harvesting the cells, and processing them for use as a protein supplement in foods. SCPs have advantages like being a renewable source of protein but also have disadvantages like potentially high nucleic acid content.
New trends in fermentation technology - Using Algae as biomassSairam Sirigina
This document discusses new trends in fermentation technology and bioreactor development for bioethanol production from algae. It outlines limitations with existing bioethanol production methods and explores using algae as an alternative biomass. Different cultivation methods for algae are described, including open ponds, tubular photobioreactors, flat plate photobioreactors, and biofilm-based systems. Harvesting and dewatering techniques like flocculation and electrochemical processes are also covered. The document concludes with an overview of converting harvested algal biomass into bioethanol through drying, crushing, fermentation and distillation.
This document discusses the commercial production of enzymes. It begins by explaining that enzymes are protein molecules produced by living cells that catalyze biochemical reactions. It then discusses the major sources of commercial enzymes, including microbes, animals and plants. Microbial sources such as fungi and bacteria are preferred due to their ability to produce large quantities of enzymes economically. The document outlines methods for increasing microbial enzyme production, including regulating production conditions, using genetic engineering to transfer genes between organisms, and protein engineering to modify enzyme properties.
The document describes the process for producing enzymes and antibiotics through fermentation. Key steps include identifying an optimal microorganism, growing starter cultures in seed tanks, conducting large-scale fermentation, isolating and purifying the target compound, and performing quality control checks before distribution. Enzymes and antibiotics are valuable industrial products created through carefully controlled microbial growth and compound extraction processes.
The document summarizes shake flask optimization studies done to determine the best conditions for growth of Pichia pastoris culture. Media type (tryptone soya broth and nutrient broth), pH (ranging from 3.0 to 8.0), and inoculum percentage were optimized. Tryptone soya broth at pH 6.0 showed the highest optical density, indicating it is the optimum medium and pH for growth. Further fine tuning of pH in the range of 5.5-6.6 in tryptone soya broth identified pH 6.0 as providing the maximum growth of the Pichia pastoris culture.
Microbial fermentation By Aneela SaleemAneelaSaleem
This document discusses different types of fermentation processes used in industry. It begins with an introduction and overview of fermentation media and microorganisms. It then describes the main types of fermentation processes - batch, fed-batch, and continuous fermentation - and factors that influence each type such as growth rate and flow rate. The document also covers solid state and submerged liquid fermentations. Important considerations for continuous fermentation are highlighted. Recent advances in fermentation technology are briefly mentioned at the end.
The document discusses various topics related to fermentation and inoculum development. It begins by defining fermentation as a metabolic process that consumes sugar in the absence of oxygen, producing organic acids, gases, or alcohol. It then discusses inoculum development, noting it is the process of developing an active microbial culture suitable for industrial fermentation. This involves building up the culture volume gradually while maintaining genetic uniformity. Finally, it provides details on developing inocula for different types of microorganisms, including unicellular bacteria, mycelial fungi, and vegetative fungi. It emphasizes the inoculum must be in a healthy, active state with sufficient volume while being free of contamination.
The document discusses plant tissue culture. It defines plant tissue culture as the technique of growing plant cells, tissues, or organs in an artificial nutrient medium under sterile conditions. The key applications of plant tissue culture include commercial plant production, conservation of endangered species, plant breeding, production of valuable compounds, and crossing distantly related plant species. The document then provides details on preparing Murashige and Skoog medium, including composition, sterilization techniques, and procedures for inoculation of plant materials like seeds and rose buds.
This ppt is prepared by Sandeep Kumar Maurya , m. pharma ,department of pharmaceutical sciences, dr. harisingh gour university sagar madhya pradesh. contains fermentation technology.
IRJET- Study of Protease Producing Bacteria and their Enzymatic Activity ...IRJET Journal
This study aimed to isolate and characterize protease producing bacteria from soil samples and optimize protease production under different parameters. Soil samples collected from a fish market were enriched in nutrient casein broth. Isolates were screened on skim milk agar plates for protease activity, identified through morphological and biochemical tests. One isolate showing the largest clearing zone was selected and identified as a gram-positive, motile bacterium. The parameters optimized for protease production were incubation time (120 hours), temperature (37°C), pH (12), carbon source (galactose), and nitrogen source (ammonium sulfate). The optimized parameters for highest enzyme activity were temperature (37°C), pH (11), substrate concentration (1% casein),
The function of the fermenter or bioreactor is to provide a suitable environment in which an organism can efficiently produce a target product—the target product might be cell biomass,metabolite and bioconversion Product. It must be so designed that it is able to provide the optimum environments or conditions that will allow supporting the growth of the microorganisms. The design and mode of operation of a fermenter mainly depends on the production organism, the optimal operating condition required for target product formation, product value and scale of production.
The choice of microorganisms is diverse to be used in the fermentation studies. Bacteria, Unicellular fungi, Virus, Algal cells have all been cultivated in fermenters. Now more and more attempts are tried to cultivate single plant and animal cells in fermenters. It is very important for us to know the physical and physiological characteristics of the type of cells which we use in the fermentation. Before designing the vessel, the fermentation vessel must fulfill certain requirements that is needed that will ensure the fermentation process will occur efficiently. Some of the actuated parameters are: the agitation speed, the aeration rate, the heating intensity or cooling rate, and the nutrients feeding rate, acid or base valve. Precise environmental control is of considerable interest in fermentations since oscillations may lower the system efficiency, increase the plasmid instability and produce undesirable end products.
BIOTECHNOLOGY IS CHALLENGING SUBJECT TO TEACH AND UNDERSTAND ALSO .....THEIR INTERESTING PART IS TO LEARN ABOUT IMMUNITY AND THE IMPORTANT PART MAJOR COMPATIBILITY COMPLEX
1. Culture media are nutrient materials prepared for the growth of microorganisms in the laboratory. Different microbes require different nutrients and conditions in the culture media.
2. Agar is commonly added to culture media to solidify it for growing bacteria on solid surfaces like Petri dishes and slants. Agar solidifies the media without degrading.
3. Pure cultures of microbes are necessary for most bacteriological work and are obtained using methods like streak plating that isolate single colonies from mixed cultures.
This document provides an overview of fermentation and bioprocess technology. It begins with definitions of fermentation and discusses the basic requirements for microbial growth. It then covers topics like batch, fed-batch, and continuous fermentation processes. Different types of fermenters and components like spargers and impellers are described. The document discusses strain selection and improvement methods. It also provides examples of industrial fermentation processes like ethanol production and antibiotic production. Finally, it gives an overview of downstream processing techniques used to purify products from fermentation broth, such as centrifugation, filtration, and extraction.
Making products using food waste (autosaved)nomin borhuu
This document discusses yeast taxonomy and growth conditions. It begins by describing the structure of yeast cells and their main macromolecular components. It then covers the chemical composition of yeast cells, noting their protein, carbohydrate, lipid, and mineral content. The document also discusses yeast taxonomy, classifying yeast under the kingdom of fungi. It notes that yeast reproduction generally occurs through budding. The final section covers the conditions necessary for yeast multiplication and growth, such as nutrients, temperature, pH, and oxygen levels.
Single cell protein (SCP) refers to edible microorganisms or their extracts used as a protein supplement. SCP can be produced using bacteria, yeast, fungi or algae through fermentation. It has high nutritional value but also has some limitations. Research is focused on improving production methods and addressing issues like high nucleic acid content and digestibility. SCP shows potential as a sustainable protein source but more work is needed before it will be widely accepted as human food.
The document provides information about animal cell culture. It discusses the requirements for culturing cells such as temperature, media, growth factors, and culture environments including pH, osmolality, and buffering. It describes the growth cycle of cells including the lag, log and plateau phases. The document outlines the basic equipment used in cell culture like incubators, laminar flow hoods, refrigerators, and microscopes. It discusses primary and secondary cell cultures, monolayer and suspension cultures, and finite versus continuous cell lines. Applications of animal cell culture mentioned include model systems, toxicity testing, cancer research, virology, and cell-based manufacturing.
Upon the evolution brought about in the fermentation technology resulted out into various methodologies for optimization of the product yield by economical consumption of the substrates. Eventually, these ventures led for the development of technologies classified into as Submerged and Solid State technologies and the latter one being the concept of interest whose detailed view will be provided in the following presentation
Single cell protein (SCP) refers to the protein content of dead, dried microorganisms like yeast, fungi, bacteria and algae. These microorganisms are grown using various carbon sources and their protein is used as a supplement for animal feed and potentially human food. SCP is produced through fermentation processes using these microorganisms, with the protein then harvested, dried and processed. SCP provides an alternative protein source that can be produced sustainably using waste materials as feedstock. Key microorganisms used include yeast, fungi, algae and bacteria. While SCP shows promise as a sustainable protein source, further research is needed to optimize production methods and ensure safety for human consumption.
Similar to Microbial Culture & Application3.pdf (20)
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
Microbial Culture & Application3.pdf
1. 18
Chapter
MI
C
R
OB
I
AL C
UL
T
UR
E AND
AP
P
L
I
C
AT
I
ONS
657
In This Chapter
18.1 Introduction
18.2 M icrob
ia
l
C
ul
tureT
e
ch
niq
ue
s
18.3 M e
a
s
ure
me
nt a
nd K
ine
ticsof
M icrob
ia
l
Growth
18.4 S
ca
l
eup of
aM icrob
ia
l
P
roce
s
s
18.5 Is
ol
a
tion of
M icrob
ia
l
P
roducts
18.6 S
tra
in Is
ol
a
tion a
nd Imp
rov
e
me
nt
18.7 A
p
p
l
ica
tionsof
M icrob
ia
l
C
ul
tureT
e
ch
nol
og
y
18.8 B
ioe
th
icsin M icrob
ia
l
T
e
ch
nol
og
y
18.1 INTRODUCTION
M
ic ro b ia l p o p u la tio n s d o m in a te th e b io s p h e re in te rm s o f m e ta b o lic im p a c t
a n d n u m b e rs . A m o n g th e v a rio u s ty p e s o f m ic ro b e s , p ro k a ry o te s a re th e
m o s t p e rv a s iv e life fo rm o n th e p la n e t, o fte n to le ra tin g e x tre m e s in p H ,
te m p e r a tu r e , s a lt c o n c e n tr a tio n , e tc . Me ta b o lic d iv e r s ity is g r e a te r a m o n g
p r o k a r y o te s th a n a ll e u k a r y o te s c o m b in e d . Me n h a v e lo n g b e e n u tiliz in g th e
b a c te r ia l a n d y e a s t a n d fu n g a l p o p u la tio n fo r th e m a n u fa c tu r in g o f v a r io u s
c h e m ic a ls , b io c h e m ic a ls , a n tib io tic s , b e v e r a g e s , e tc . P r o d u c tio n o f a n tib io tic s ,
2. 658 INTRODUCTION TO B
IOTE
CHNOL
OGY AND GE
NE
TIC E
NGINE
E
RING
alcohols, vinegar, amino acids, vitamins, therapeutic antibodies, acetone and other
solvents, and recombinant proteins is accomplished by the large-scale cultivation
of microbial cells such as bacteria, algae, yeast, and fungus on industrial scale. In
all these industrial applications the metabolic activities or the biochemical pathw ays
are used for the production of specific chemicals w ith the consumption of the
substrates or a carbon source such as sucrose. Here, the microbial culture acts as a
factory, w here the substrate is the raw material. It is converted into the product
and secreted into the media. T he product can be recovered from the media w ith a
process called dow nstream processing. T here is a limitation for a single cell to
convert the raw material into products in a given period of time. It is possible to
calculate the rate of product formation by a single cell under a specific metabolic
condition, if w e know the q uantity of product formed over a period of time and
the number of cells in the culture. If w e w ant to produce a specific q uantity of the
product over a period of time it is possible to calculate the number of bacterial or
microbial cells req uired to operate the bioprocess on an industrial scale.
L ike any other chemical eq uation this microbial-mediated biotransformation
can also be considered a chemical reaction and can be expressed by a chemical
eq uation:
CwHxOyNz + aO2 + bHgOhN → cCHaObNd + dCO2 + eH2O
E ven though the microbial conversion of a substrate can be compared to a
chemical reaction, w here the reactant is converted into a product, the efficiency of
conversion w ill be comparatively less. A chemical reaction req uires an appropriate
temperature, pressure, pH, and solvent system for maximum product output. T he
microbial system also has to be provided w ith the optimum environmental and
nutritional conditions such as temperature, pH, and the correct substrate for
converting it into the product. T he efficiency of microbial conversion of substrate
into product is comparatively less because a major part of the metabolic energy is
utilized for the generation of biomass by cell grow th and multiplication.
18.2 MICROBIAL CULTURE TECHNIQUES
As stated previously, microbial cultures should be provided w ith the req uired
chemical and physical environment for proper multiplication and physiological
state, so that the cells can carry out the req uired bioconversion satisfactorily. T he
chemical environment of a microbial cell is its nutritional conditions in w hich it is
grow ing. It also includes the correct pH and temperature.
3. MICROBIAL C
ULTURE AND AP
P
LICATIONS 659
Nutrients for Microbial Culture
Like any other living system, microorganisms also require a source of energy, carbon,
nitrogen, oxygen, iron and other minerals, micronutrients, and water for growth,
and multiplication. All these nutrients that are essential for the growth and
multiplication of microbial organisms are supplied in the form of nutrient media.
F or laboratory-scale cultivation we may use certain costly media components, but
for industrial purposes they should be economical and readily available. The media
that we use for growing microbes may be synthetic, semi-synthetic, or completely
natural. If the nutritive components of the media are not of natural origin, such
nutritive media are known as synthetic media, which we can synthesize in the
laboratory following certain recipes, mixing the required salts, minerals, and carbon
source. There are a large number of commercially-available nutrient media, which
contain both salts and minerals. S uch nutrient media are known as semi-synthetic
media. F or example, commercially available nutrient broth, trypticase soya broth
(TS B ), brain-heart infusion (B HI) broth, yeast extract, potato dextrose agar, casein
digest, etc., are some examples of semi-synthetic media. F or laboratory-scale
cultivation of bacteria and other microorganisms, these synthetic or semi-synthetic
media are preferred, but for industrial-scale cultivation these media are not
recommended from an economical point of view. F or commercial purposes, the
recommended media should be cheap and available year round. The following
are the minimum components required in a microbial medium for cultivation of
microbes in a laboratory:
C arb o n so u rce. A simple carbon source, which is simple to use and easily
available, can be used. S ugars such as glucose, lactose, sucrose, and complex
polysaccharides such as starch, glycogen cellulose, a mixture of various
carbohydrates, and other compounds such as cereal grain powders, cane
molasses, etc., are usually used as carbon sources in microbial culture media.
The main purpose of the carbon source is to provide energy and carbon skeleton
for the synthesis of various other biological compounds.
N itro g en so u rces. The major types of nitrogen sources used in culture media
are ammonium salts, urea, animal tissue extracts, amino acid mixtures, and
plant-tissue extracts.
M icro elements o r trace elements. Elements required in small amounts or in
traces are to be added into the medium as salts in required amounts. The
elements such as copper, cobalt, iron, zinc, manganese, magnesium, etc., are
the microelements.
G ro w th facto rs. G rowth factors are certain organic compounds that are essential
for the growth and multiplication of cells, but cannot be synthesized by the
cells. S uch compounds should be supplemented in the medium. Certain amino
acids and vitamins are also included in this category.
4. 660 INTRODUCTION TO BIOTECHNOLOGY AND GENETIC ENGINEERING
Anti-foams. This is not a nutritive component of the media. Media rich in
nutritive components such as starch, protein, and other organic material and
also the proteins and other products secreted by the growing cells can result in
excessive foaming while the culture media is agitated for aeration. To prevent
the formation of foam some anti-foaming agents are included in the media.
Certain types of fatty acids such as olive oil and sunflower oil and silicones are
commonly used in cell cultures as anti-foam agents.
E nergy sources. The carbon sources used in culture media such as
carbohydrates, sugars, proteins, lipids, etc., can work as energy sources for the
growth and metabolism of the microbial cells.
W ater. W ater is the base of any culture media, whether it is liquid or solid. In
solid culture media such as the media of solid state fermentation or agar media
the quantity of water is comparatively less than liquid media. In laboratory
experiments, single-distilled water or double-distilled water is usually used.
But in large-scale microbial cultivation for industrial purposes, the pH and the
dissolved salts present should be considered when formulating the media
requirements and its concentration. W ater is also required for a large number of
other services in the laboratory such as cooling, heating, steaming, etc. Therefore,
anylaboratoryshouldbeprovidedwith a sourceofcleanwaterofconsistentquality.
Culture Procedures
1 . S teriliz ation. The media and culture vessel have to be sterilized to prevent the
growth of unwanted microorganisms and thus contamination. If laboratory-
scale experiments are carried out in 1 0 0 to 1 ,0 0 0 ml flasks, or in lesser volumes
such as 5 0 ml or 1 0 ml, the media along with the culture flasks or vials can be
steam-sterilized with an autoclave. D epending on the quantity of the materials
autoclaved, the sterilization can be carried out alternatively in a pressure cooker
of convenient size. Steam-sterilization with an autoclave or pressure cooker is
carried out at 1 20 °C for 1 5 to 20 minutes under 1 5 psi pressure.
W hen microbes are cultivated in a fermentor for large-scale operation, it is
convenient to sterilize the fermentor as a whole with or without media. Media
may be sterilized separately or in situ, in the fermentor itself. Steam is used for
the sterilization of the media and fermentor, by passing the steam through the
sterilization jacket or the coil around the fermentor. W hen the fermentor is
sterilized without media in it, steam can be sparged into the vessel through all
openings, allowing it to exit very slowly. Sparging is a process by which sterile
air or steam is allowed to pass through the medium in the vessel with the help
of a sparging device placed at the bottom of the fermentor. The steam pressure
is held at 1 5 psi for 20 to 3 0 minutes while circulating or holding the steam
within the vessel or in the jacket (Figure 1 8 .1 ).
5. MICROBIAL CULTURE AND APPLICATIONS 661
2. Environment for microbial growth. The nutrient composition of the medium,
the ionic concentration of salts, pH, and temperature influence the growth of
microorganisms in the culture and its metabolic state. Most of the bacteria
grow at neutral pH, where as yeast and fungi prefer acidic pH. Similarly,
different organisms prefer different optimum temperatures for active growth
and multiplication. The optimum temperature has to be maintained in the
culture with the help of an incubator in the case of small-scale cultures and
circulating water of the appropriate temperature through the jacket of the
fermentor.
3 . Aeration and mix ing. Mixing of the broth is essential for the uniform
distribution of the nutrients and the microbial population in the culture.
Aeration is needed for the easy gas exchange between the medium and the
environment. Aerated medium will be rich in oxygen. Aeration and mixing
can be easily achieved by shaking the medium on a shaker in the case of small-
scale cultures (shake flasks cultures). In large-scale cultivation in bioreactors
the transfer of oxygen to organisms is very difficult because it requires proper
mixing. In fermentors, the proper mixing of cells, media components, and
oxygen is achieved by stirring the medium with the help of a mechanical stirrer
with baffles attached to it. Baffles help in maintaining turbulence. Microbial-free
air passed through the media ensures proper aeration, and this forced aeration
also helps in the mixing of media, cells, and oxygen.
Microbial Culture Equipment
In the laboratory, microbial cells can be grown in tubes and vials, when the volume
is five to ten ml, and in Erlenmeyer flasks when the volume is 100 to 1,000 ml.
Improvements in the culturing of microbes can be done by making improvements
in the design of the flasks and also by using shakers.
Baffle Flasks
Baffle flasks are the modified flasks for microbial cultivation, in which there are
v-shaped notches or indentations in the sides of the flasks. The presence of baffles
improves the efficiency of oxygen transfer and thereby the growth of microbes
because the baffles increase the turbulence while the media is agitated on a shaker.
S
h
aker
s
Shakers are the special equipment designed for rotating a platform orbitaly, so
that the culture flasks with media kept on the platform of the shaker will be
continuously agitated. This agitation helps the medium to be homogeneous in
cell-mass distribution, media components, and efficient oxygen transfer.
6. 662 INTRODUCTION TO BIOTECHNOLOGY AND GENETIC ENGINEERING
Fermentors
These are bioreactors used for the cultivation of microbial cells on large scale under
controlled conditions for industrial purposes. This closed metallic or glass vessel
has the adequate arrangement for aeration, mixing of media by agitation,
temperature control, pH control, anti-foaming, control of overflow, sterilization of
media and vessel, cooling, and sampling (removal of sample, while the fermentor
is on). Agitation of the media in the bioreactor may be through stirring or aeration
or both. This equipment is convenient for operation continuously for a number of
days. The essential parts of a laboratory fermentor are given in Figure 18.1.
Gases out
S terile air in
N utrien ts in
S am p lin g /
p rod uc t out
A c id /b ase in
p H m on itor
C oolin g w ater/steam out
T em p erature
m on itor
S tirrer
S tirrer p ad d le
R in g of air
outlets
C oolin g w ater/steam in
FIGURE 18.1 Di
a
g
r
a
m s
k
e
t
c
h o
fa l
a
b
o
r
a
t
o
r
yf
e
r
me
n
t
o
rs
h
o
wi
n
g t
h
ee
s
s
e
n
t
i
a
l
c
o
mp
o
n
e
n
t
s
.
As indicated in the figure, the bioreactors are provided with controls for
monitoring and adjusting the many physical and chemical parameters such as
temperature, pH, nutrient composition, foaming, etc. Maximum cell growth and
product formation can be achieved by controlling these parameters that assist cell
growth and metabolism leading to high output of the product. A stirred tank
bioreactor is the most commonly used bioreactor for microbial cultivation, in which
the microbial medium is stirred with an impeller. A high density of metabolically
7. MICROBIAL CULTURE AND APPLICATIONS 663
active cells in the medium can result in sudden depletion of dissolved oxygen
creating an anaerobic condition in the medium. This can result in serious
consequences in the quality of the product or even in the type of products formed
in the fermentation reaction. Similarly, the cell growth and product formation can
alter pH of the medium, which can also create problems in the further growth and
metabolism of the cell cultures. R apid growth also results in the depletion of
essential nutrients that directly link to the growth and metabolism that causes the
production of the product. All these changes are monitored by the accessories of
the fermentor or bioreactor and are accordingly indicated or rectified automatically.
For example, whenever there is a change in pH from the optimum value,
automatically a sufficient amount of acid or alkali is added to the media to keep
the optimum pH constant. Similarly, if there is foaming in the media the sensor
will detect the foam formation and accordingly, the antifoam agent is delivered
into the medium to prevent the foaming.
In addition to the industrial type of bioreactors or fermentors, there are
fermentors of small volumes suitable for operating in the laboratories, known as
laboratory fermentors. These laboratory fermentors are for 10 to 100 liters of volume
and are used for optimizing culture conditions and nutritional parameters for better
growth of cells and production of metabolites for conducting research studies in
the laboratory.
Types of Microbial Cultures
The culturing of the microbial system can be achieved in different ways. The type
of culture method sometimes depends on the type of the microbial system or on
the type of the product that we expect. For example, one can get two entirely
different products from the same organism by changing the nutritional and other
parameters or even culturing vessels.
1. B atch culture. This is a small-scale laboratory experiment in which a microbial
culture is growing in a small volume flask. It consists of a limited volume of
broth culture in a flask inoculated with the bacterial or microbial inoculum
and follows a normal growth phase. It is a closed-culture system because the
medium contains a limited amount of nutrients and will be consumed by the
growing microorganisms for their growth and multiplication with the excretion
of certain metabolites as products. In batch cultures, the nutrients are not
renewed and the exponential growth of cells is limited to a few generations.
The growth phase of the culture consists of an initial lag phase, a log phase or
the exponential growth phase, and a stationary phase. During the log phase
the consumption of the nutrients will be the maximum resulting in the
maximum biomass output with the excretion of the product. At the stationary
phase the rate of growth decreases and becomes zero. This is because at the
8. 664 INTRODUCTION TO BIOTECHNOLOGY AND GENETIC ENGINEERING
stationary phase the cells are exposed to a changed environment where there
is only a small amount of nutrients and more cells along with the accumulation
of metabolites, which may have a negative effect on the growth of the cells.
2. Fed-batch culture. The batch culture can be made into a semi-continuous
culture or fed-batch culture by feeding it with fresh media sequentially at the
end of the log phase or in the beginning of the stationary phase without
removing cells. Because of this the volume of the culture will go on increasing
as fresh media is added. This method is specially suited for cultures in which
a high concentration of substrate is inhibitory to cell multiplication and biomass
formation. In such situations the substrate can be fed at low concentrations to
achieve cell growth. This method can easily produce a high cell density in the
culture medium, which may not be possible in a batch fermentor or shake
flask culture. This is especially important when the product formation is
intracellular to achieve maximum product output per biomass.
3. Continuous culture. Bacterial cultures can be maintained in a state of
exponential growth over long periods of time using a system of continuous
culture, designed to relieve the conditions that stop exponential growth in
batch cultures. Continuous culture, in a device called a chemostat, can be used
to maintain a bacterial population at a constant density, a situation that is, in
many ways, more similar to bacterial growth in natural environments.
This is a very convenient method to get continuous cell growth and product
formation over a long period of time. In continuous culture, the nutrient
medium including the raw material is supplied at a rate that is equal to the
volume of media with cells and product displaced or removed from the culture.
The volume removed and the volume added is the same. In effect there is no
change in the net volume as well as the chemical environment of the culture.
In a chemostat, the growth chamber is connected to a reservoir of sterile
medium. Once the growth is initiated, fresh medium is continuously supplied
from the reservoir (Figure 18.2). The volume of fluid in the growth chamber is
maintained at a constant level by some sort of overflow drain. Fresh medium
is allowed to enter into the growth chamber at a rate that limits the growth of
the bacteria. The bacterial cells grow (cells are formed) at the same rate at
which bacterial cells (and spent medium) are removed by the overflow. The
rate of addition of the fresh medium determines the rate of growth because
the fresh medium always contains a limiting amount of an essential nutrient.
Thus, the chemostat relieves the insufficiency of nutrients, the accumulation
of toxic substances, and the accumulation of excess cells in the culture, which
are the parameters that initiate the stationary phase of the growth cycle. The
bacterial culture can be grown and maintained at relatively constant conditions,
depending on the flow rate of the nutrients.
9. MICROBIAL CULTURE AND APPLICATIONS 665
Reservoir
containing
culture
medium
F low-rate
regulator
O verflow
E ffluent
FIGURE 18.2 S
chematic d
iagram of a chemostat,
a d
ev
ice u
sed
for the continu
ou
s cu
ltu
re of microbes. T
he
chemostat reliev
es the env
ironmental cond
itions
that restrict growth by continu
ou
sly su
pplying
nu
trients to cells andremov
ing waste su
bstances
and spent cells from the cu
ltu
re med
iu
m.
If the chemical environment is constant in a chemostat continuous culture, the
cell density is constant in a turbidostat culture, which is also a continuous culture.
Since the culture is fed with the fresh medium at specific rate, a steady state of
growth and metabolism is achieved. At a steady state, the cell multiplication and
substrate consumption for growth and product formation occur at a fixed rate.
The growth rate is maintained constantly. The formation of new biomass is balanced
with the removal of cells from the outlet. Continuous culture is very suitable for
the production of cell biomass and products, if it is excreted into the medium. It is
widely used for the production of single-cell protein from liquid effluents as a
byproduct of the waste treatment. The organic waste present in the effluent is
converted into microbial biomass, which is known as single-cell proteins.
18.3 MEASUREMENT AND KINETICS OF MICROBIAL GROWTH
Growth is an orderly increase in the quantity of cellular constituents. It depends
on the ability of the cell to form new protoplasm from nutrients available in the
environment. A proper understanding regarding microbial growth is essential to
utilize the microbial process to get maximum product output. Among the various
10. 666 INTRODUCTION TO BIOTECHNOLOGY AND GENETIC ENGINEERING
types of microorganisms there are basically four general patterns of cell
multiplication. Bacteria mainly increase in number by binary fission, yeast multiply
by budding, fungi increas the biomass by the elongation of mycellium and its
branching, and in the case of virus, there is no regular pattern for multiplication,
mainly because its multiplication is host dependent and grow intracellularly.
Measurement of Microbial Growth
In bacteria, multiplication takes place by simple division of a cell into two by a
process called binary fission. The growth and division of a bacterial cell involves
increase in cell mass and number of ribosomes, duplication of the bacterial
chromosome, synthesis of new cell wall and plasma membrane, partitioning of the
two chromosomes, septum formation, and cell division. This asexual process of
reproduction is called binary fission.
During this process, there is an orderly increase in cellular structures and
components, replication and segregation of the bacterial DNA, and formation of a
septum or cross wall, which divides the cell into two progeny cells. The process is
coordinated by the bacterial membrane, perhaps by the mesosomes. The DNA
molecule is believed to be attached to a point on the membrane where it is replicated.
The two DNA molecules remain attached at points side-by-side on the membrane
while new membrane material is synthesized between the two points. This draws
the DNA molecules in opposite directions while new cell wall and membrane are
laid down as a septum between the two chromosomal compartments. When septum
formation is complete, the cell splits into two progeny cells. The time interval
required for a bacterial cell to divide or for a population of bacterial cells to double
is called the generation time. Generation time for bacterial species growing in
nature may be as short as 15 minutes or as long as several days. For unicellular
organisms such as bacteria, growth can be measured in terms of two different
parameters: changes in cell mass and changes in cell numbers.
Growth K
inetics and S
pecific Growth R
ate
When bacteria are grown in a closed system (also called a batch culture) such as a
test tube, the population of cells almost always exhibits these growth dynamics:
cells initially adjust to the medium (lag phase) until they can start dividing regularly
in the exponential phase. When their growth becomes limited, the cells stop dividing
(stationary phase), until eventually they show loss of viability (death phase).
Growth is expressed as change in the number of viable cells versus time or the cell
biomass versus time.
Growth of cells in a microbial culture under a steady state or balanced growth
can be compared to a chemical reaction, in which the substrate is getting converted
11. MICROBIAL CULTURE AND APPLICATIONS 667
into products. In a microbial culture under a steady state the substrate is the
nutrients and the product is the cell biomass. In such a reaction the rate of growth
will be proportional to the cell biomass present in the culture. The cell culture
behaves like an autocatalytic reaction. When the microbial culture is under a steady
state the rate of increase in cell biomass dX/ dt is equal to the product of specific
growth and cell concentration (biomass concentration).
DX/ dt = µX (1)
where X is the cell concentration (gm/ L) and µ is the specific growth rate (in hour– 1).
The specific growth rate µ = dX/ dt × 1/ X, which is an index of rate of growth
of cells in those particular conditions. Specific growth rate can be determined by
plotting dX/ dt against X, the cell concentration, and determining the slope of the
straight line. It is possible to calculate the generation time or the doubling time of
the organism or bacterial cell, if we know the initial and final cell concentration of
the culture and the specific growth rate.
The cell biomass at the starting of exponential growth is X and after time, t, it
is 2X. Time required for doubling the biomass or the generation time of the cell can
be calculated by following the above equation (Equation No. 1).
ln 2X/ t = µX
ln 2X/ X = µt
ln 2 = µt
Therefore, t = ln 2/ µ
t = 0.6 9 3/ µ (2 )
Here t is the generation time or the doubling time of the cells. If the specific
growth ‘µ’ of the cells is calculated it can be substituted in the above equation to
determine the generation time or the doubling time. From this it is very clear that
the doubling time and specific growth rate are inversely related. As the doubling
time increases, the specific growth rate decreases. The microbial cell cultures usually
have a high specific growth rate, because they have short doubling time or
generation time.
The cell numbers of the microbial culture at different time intervals can be counted
and this data can be used for calculating the specific growth rate as follows:
ln 2X/ X = µt or ln 2X – X = µ (t – t0)
on converting natural logarithm to logarithm to the base 10
log10 2X – log10 X = µ/ 2.303 (t – t0)
2X and X represent the amount of microbial cells at time t and t0.