Growth Curve of Bacteria SlideShare
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The bacterial growth curve shows changes in the number of bacteria over time in a culture. It consists of four phases: lag phase as bacteria adapt to their environment, exponential or log phase as bacteria divide exponentially, stationary phase as nutrients are depleted and waste builds up slowing growth, and death phase as bacteria die off due to lack of nutrients and buildup of toxins. The curve represents the growth of heterotrophic bacteria that obtain nutrients from external sources.
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Bacterial growth curve
Bacterial growth follows four phases: lag, log (exponential), stationary, and decline. During lag phase, bacteria adapt to their environment and prepare for growth. The log phase is characterized by rapid, exponential cell division. As nutrients become depleted, growth slows and enters stationary phase where the cell population levels off. In decline phase, bacteria run out of nutrients and die off, though a small number of survivors may persist. Bacterial growth is influenced by numerous environmental factors like nutrient levels, temperature, pH, oxygen, and water availability. The optimal conditions allow bacteria to enter log phase and multiply at their highest rate.
Bacterial growth curve
Bacterial growth curve consists of four phases:
1. Lag phase where bacteria adjust to new environment and do not divide.
2. Exponential or log phase where bacteria divide rapidly and population increases exponentially.
3. Stationary phase where growth rate equals death rate resulting in constant population size.
4. Decline or death phase where population decreases as number of dying cells exceeds reproducing cells due to nutrient depletion and waste accumulation.
Growth curve of bacteria
1. Bacteria growing in batch culture produce a growth curve with up to four distinct phases: lag, log, stationary, and death.
2. During the lag phase, bacteria are adjusting to their new medium and preparing for active growth.
3. The log phase is when bacteria grow exponentially as cell division occurs rapidly under favorable conditions.
4. As nutrients become depleted and waste accumulates, bacteria enter the stationary phase where growth stops.
5. In the death phase, cell numbers decline as bacteria can no longer survive due to nutrient depletion and waste accumulation.
Bacterial growth curves
all information regarding the bacterial growth curve that will required for nursing students.........
Factors affecting growth of bacteria
The physical factors affects the growth of microorganism.
1) Temperature
Temperature is the most important factor that influences the rate of enzyme catalysed reactions and rate of growth.
For every organisms there is an optimum temperature for growth and minimum temperature for inhibiting the growth.
Most extreme the microbes need liquid water to grow.(330C).
some algae and fungi grow at 55-60 degreeC.
Prokaryotes are grow at 100 degreeC.
Based on temperature the microorganisms are classified into two 4.
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This document discusses techniques for cultivating viruses. It explains that viruses require living host cells to replicate and describes three main cultivation methods: animal inoculation, embryonated egg inoculation, and tissue culture. Animal inoculation involves infecting animals like mice to isolate and study viruses, but it is expensive and raises welfare issues. Embryonated egg inoculation is commonly used to grow viruses by inoculating eggs at specific sites, and it is cost-effective but each virus grows at different sites. Tissue culture uses cell monolayers and is versatile but requires specialized facilities and technicians. The document provides details on each technique's advantages, disadvantages and applications.
bacterial spore.ppt
This document discusses bacterial spores, including their definition, structure, classification, properties, resistance, germination, and demonstration. Key points include: bacterial spores are dormant, resistant structures formed by certain bacteria under stress; they have a core surrounded by membranes and a thick cortex and coat; shapes include spherical, oval, elongated; properties include metabolic dormancy and extreme resistance to heat, chemicals, radiation; germination occurs when activated spores encounter nutrients and results in outgrowth into vegetative cells; staining methods can be used to visualize spores microscopically.
Bacterial classification and its structure
Bacteria are classified in several ways:
1. By staining (Gram positive/negative, acid-fast), shape (cocci, bacilli), motility, environment (aerobic/anaerobic).
2. The bacterial cell has a cell wall, cell membrane, flagella/fimbriae and cytoplasm. The cell wall provides structure and protection through its peptidoglycan layer.
3. Bacteria are further classified based on nutrition sources, temperature, pH and salt tolerance ranges they thrive in. Most bacteria serve important ecological roles while some can cause disease.
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Bacterial growth curve
Bacterial growth follows four phases: lag, log (exponential), stationary, and decline. During lag phase, bacteria adapt to their environment and prepare for growth. The log phase is characterized by rapid, exponential cell division. As nutrients become depleted, growth slows and enters stationary phase where the cell population levels off. In decline phase, bacteria run out of nutrients and die off, though a small number of survivors may persist. Bacterial growth is influenced by numerous environmental factors like nutrient levels, temperature, pH, oxygen, and water availability. The optimal conditions allow bacteria to enter log phase and multiply at their highest rate.
Bacterial growth curve
Bacterial growth curve consists of four phases:
1. Lag phase where bacteria adjust to new environment and do not divide.
2. Exponential or log phase where bacteria divide rapidly and population increases exponentially.
3. Stationary phase where growth rate equals death rate resulting in constant population size.
4. Decline or death phase where population decreases as number of dying cells exceeds reproducing cells due to nutrient depletion and waste accumulation.
Growth curve of bacteria
1. Bacteria growing in batch culture produce a growth curve with up to four distinct phases: lag, log, stationary, and death.
2. During the lag phase, bacteria are adjusting to their new medium and preparing for active growth.
3. The log phase is when bacteria grow exponentially as cell division occurs rapidly under favorable conditions.
4. As nutrients become depleted and waste accumulates, bacteria enter the stationary phase where growth stops.
5. In the death phase, cell numbers decline as bacteria can no longer survive due to nutrient depletion and waste accumulation.
Bacterial growth curves
all information regarding the bacterial growth curve that will required for nursing students.........
Factors affecting growth of bacteria
The physical factors affects the growth of microorganism.
1) Temperature
Temperature is the most important factor that influences the rate of enzyme catalysed reactions and rate of growth.
For every organisms there is an optimum temperature for growth and minimum temperature for inhibiting the growth.
Most extreme the microbes need liquid water to grow.(330C).
some algae and fungi grow at 55-60 degreeC.
Prokaryotes are grow at 100 degreeC.
Based on temperature the microorganisms are classified into two 4.
Cultivation of virus
This document discusses techniques for cultivating viruses. It explains that viruses require living host cells to replicate and describes three main cultivation methods: animal inoculation, embryonated egg inoculation, and tissue culture. Animal inoculation involves infecting animals like mice to isolate and study viruses, but it is expensive and raises welfare issues. Embryonated egg inoculation is commonly used to grow viruses by inoculating eggs at specific sites, and it is cost-effective but each virus grows at different sites. Tissue culture uses cell monolayers and is versatile but requires specialized facilities and technicians. The document provides details on each technique's advantages, disadvantages and applications.
bacterial spore.ppt
This document discusses bacterial spores, including their definition, structure, classification, properties, resistance, germination, and demonstration. Key points include: bacterial spores are dormant, resistant structures formed by certain bacteria under stress; they have a core surrounded by membranes and a thick cortex and coat; shapes include spherical, oval, elongated; properties include metabolic dormancy and extreme resistance to heat, chemicals, radiation; germination occurs when activated spores encounter nutrients and results in outgrowth into vegetative cells; staining methods can be used to visualize spores microscopically.
Bacterial classification and its structure
Bacteria are classified in several ways:
1. By staining (Gram positive/negative, acid-fast), shape (cocci, bacilli), motility, environment (aerobic/anaerobic).
2. The bacterial cell has a cell wall, cell membrane, flagella/fimbriae and cytoplasm. The cell wall provides structure and protection through its peptidoglycan layer.
3. Bacteria are further classified based on nutrition sources, temperature, pH and salt tolerance ranges they thrive in. Most bacteria serve important ecological roles while some can cause disease.
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Nutrition Requirement of Bacteria
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Bacteria have a simple structure compared to eukaryotic cells, lacking organelles. Their small size allows rapid growth and inhabitation of diverse environments. Bacterial cells contain a cytoplasm surrounded by a cell membrane and cell wall. The cytoplasm holds the circular chromosome, ribosomes for protein production, and storage structures. Some bacteria have flagella for mobility or pili for attachment. Gram-positive bacteria have a thick peptidoglycan cell wall, while Gram-negatives have a thin wall and an outer membrane. This membrane structure contributes to differences in antibiotic susceptibility between Gram-positive and Gram-negative bacteria.
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This document discusses the growth curves of microorganisms like bacteria and how their numbers are represented using a logarithmic scale. It then describes the four phases of bacterial growth - lag, log (exponential), stationary, and death phase. The log phase is when bacteria grow and divide most rapidly. The document also differentiates between batch and continuous culture methods for food processing using bioreactors, noting that continuous culture maintains bacteria in the log phase for ongoing production.
Structure of bacterial cell
This document summarizes the structure of bacterial cells. It describes the key components including the cell wall, plasma membrane, and intracellular and extracellular structures. The cell wall differs between gram-positive and gram-negative bacteria. Gram-positive walls are thicker and contain higher amounts of peptidoglycan while gram-negative walls are thinner and contain an outer lipopolysaccharide membrane. Intracellular structures discussed include the nucleoid, ribosomes, plasmids, and mesosomes. Extracellular structures include flagella, pili, and capsules. Bacteria range in size from 0.4 to 1.5 micrometers and have characteristic shapes including cocci, bacilli, spirilla and spirochetes.
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Bacterial capsules are gelatinous envelopes that surround bacterial cells and are usually polysaccharide or polypeptide in nature. Capsules contribute to virulence in pathogenic bacteria by making the cells more resistant to phagocytosis. Capsulated bacteria form distinct colony morphologies compared to unencapsulated bacteria. Examples of bacteria that produce capsules include Streptococcus pneumoniae, Klebsiella, Haemophilus influenzae, Neisseria meningitidis, and Pseudomonas aeruginosa. Capsules protect bacteria by attaching to surfaces, protecting from phagocytosis, and providing resistance to environmental stresses.
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The document summarizes Gram staining, a method developed by Hans Christian Gram in 1883 to differentiate between bacterial species. Gram staining uses crystal violet dye and iodine to stain bacteria, then decolorizes them with acetone or alcohol. Gram-positive bacteria retain the crystal violet dye after decolorization due to their thick peptidoglycan cell wall, appearing purple or blue. Gram-negative bacteria's thinner cell wall is unable to retain the dye after decolorization but can be counterstained pink with safranin. This differentiation depends on differences in bacterial cell wall composition and structure.
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The document provides information about pathogenesis presented in a student assignment. It defines pathogenesis and lists some general terms used. It discusses virulence factors and provides examples. It describes the stages of pathogenesis as exposure, adhesion, invasion, and infection. It explains how pathogens penetrate host defenses and produce toxins. It covers transmission of disease and lists references. The skill achieved from the seminar is described as communication skills, confidence, better subject knowledge, presentation skills, and motivation.
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Identification of bacteria
1. Identification of unknown bacteria is an important task for microbiologists that involves determining what taxon the bacteria belongs to.
2. There are three main categories of identification methods - phenotypic/morphological analysis, immunological/serological techniques, and genetic/molecular methods.
3. Staining techniques like simple staining, gram staining, and acid-fast staining are used for morphological analysis and involve using dyes to distinguish cell structure and characteristics. Biochemical tests like IMViC are also used to identify bacteria based on enzymatic reactions and metabolite production.
Bacterial cell wall
The bacterial cell wall lies outside the cell membrane and provides several key functions for the cell. In gram-positive bacteria, the cell wall is thick and largely composed of peptidoglycan, while in gram-negative bacteria it is thinner with an additional outer membrane. Peptidoglycan is a polymer mesh made of sugars and amino acids that maintains cell shape and integrity. The structures and components of the cell wall help determine how the cell will interact with its environment and respond to antibiotics.
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physical factors and growth curve.pdf
1. Bacterial growth curve consists of four phases: lag phase, log/exponential phase, stationary phase, and death phase.
2. During the lag phase, bacteria adapt to their environment and prepare for reproduction through metabolic activity without cell division.
3. The exponential phase is characterized by rapid, exponential cell division until nutrients are exhausted or toxic byproducts accumulate.
Bacterial growth.pptx
This document discusses bacterial growth and measurement. It defines bacterial growth as an increase in cell number through cell division under ideal nutrient conditions. The growth rate and generation time are described, with examples given of generation times for some common bacteria ranging from 12 minutes to over 12 hours. The bacterial growth curve is summarized as having four phases - lag phase, exponential or logarithmic phase, stationary phase, and decline phase. Methods for measuring bacterial growth directly through total or viable cell counts or indirectly through turbidity are also outlined.
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This document summarizes the structure of bacterial cells. It describes the key components including the cell wall, plasma membrane, and intracellular and extracellular structures. The cell wall differs between gram-positive and gram-negative bacteria. Gram-positive walls are thicker and contain higher amounts of peptidoglycan while gram-negative walls are thinner and contain an outer lipopolysaccharide membrane. Intracellular structures discussed include the nucleoid, ribosomes, plasmids, and mesosomes. Extracellular structures include flagella, pili, and capsules. Bacteria range in size from 0.4 to 1.5 micrometers and have characteristic shapes including cocci, bacilli, spirilla and spirochetes.
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The document provides information about pathogenesis presented in a student assignment. It defines pathogenesis and lists some general terms used. It discusses virulence factors and provides examples. It describes the stages of pathogenesis as exposure, adhesion, invasion, and infection. It explains how pathogens penetrate host defenses and produce toxins. It covers transmission of disease and lists references. The skill achieved from the seminar is described as communication skills, confidence, better subject knowledge, presentation skills, and motivation.
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Fungi range from unicellular yeasts to multicellular molds. Their cells contain filaments called hyphae that may be septate or aseptate, with septa that often have pores allowing cytoplasm to flow between cells. Hyphae aggregate to form a mycelium, which can be either vegetative hyphae that absorb nutrients or aerial hyphae that produce reproductive spores. Fungi reproduce asexually through budding or formation of spores and exist in forms from yeasts and yeast-like cells to filamentous mycelium or changing between yeast and mycelium depending on temperature.
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2. There are three main categories of identification methods - phenotypic/morphological analysis, immunological/serological techniques, and genetic/molecular methods.
3. Staining techniques like simple staining, gram staining, and acid-fast staining are used for morphological analysis and involve using dyes to distinguish cell structure and characteristics. Biochemical tests like IMViC are also used to identify bacteria based on enzymatic reactions and metabolite production.
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The bacterial cell wall lies outside the cell membrane and provides several key functions for the cell. In gram-positive bacteria, the cell wall is thick and largely composed of peptidoglycan, while in gram-negative bacteria it is thinner with an additional outer membrane. Peptidoglycan is a polymer mesh made of sugars and amino acids that maintains cell shape and integrity. The structures and components of the cell wall help determine how the cell will interact with its environment and respond to antibiotics.
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Chapter 3 Microbial growth
Microbial growth involves an increase in cell numbers through cell division and reproduction. There are four phases of microbial growth: lag phase as cells adapt to their environment; log or exponential phase of rapid cell division; stationary phase as resources are depleted and growth balances mortality; and death phase as cells die off. Microbial growth is influenced by environmental factors like pH, temperature, gas availability, and pressure.
Synchronous-culture-and-continuous-cultivation (2).pptx
Bacterial growth occurs in distinct phases as bacteria multiply in a closed system. There is an initial lag phase where cells acclimate to their environment but do not divide. This is followed by the exponential or log phase where rapid cell division occurs. As nutrients become depleted, the stationary phase begins where growth plateaus. Eventually cell death exceeds growth and the death phase ensues. Bacterial growth is influenced by intrinsic factors like temperature and pH as well as extrinsic factors such as available nutrients.
Synchronous-culture-and-continuous-cultivation (2).pptx
Bacterial growth occurs in distinct phases as bacteria multiply in a closed system. There is an initial lag phase where cells acclimate to their environment but do not divide. This is followed by the exponential or log phase where rapid cell division occurs. As nutrients become depleted, the stationary phase begins where growth plateaus. Eventually cell death exceeds growth and the death phase ensues. Bacterial growth is influenced by intrinsic factors like temperature and pH as well as extrinsic factors such as available nutrients.
Microbial Growth curve
1. The document discusses microbial growth curves and the different phases of bacterial growth: lag, exponential, stationary, and death phase.
2. It explains key concepts like generation time, growth rate constant, batch and continuous culture techniques, and the importance of understanding growth curves.
3. The mathematics of growth is also covered, including definitions and calculations of generation time and growth rate constant.
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very good ppt as mach as possible give you abrife description to your bacteriology or microbiology courses and any related conceptes with regarding to this are avaliable here so try to reach out there and get the most exiting documenntes for your reserch for your presentation or assyignment
Microbial growth
The document summarizes key aspects of microbial growth including:
1. Microbial growth occurs through cell division and reproduction methods like binary fission.
2. A bacterial growth curve consists of four phases - lag, log (exponential), stationary, and death. The generation time is the time required for a population to double.
3. Bacterial growth can be measured by cell mass, cell number, or viable cell counts using techniques like plate counts and membrane filtration.
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Growth Curve of Bacteria SlideShare
- 1. Growth Curve of Bacteria Food Microbiology By Sayanta Mitra
- 2. What is Bacterial Growth Curve? Bacterial growth curve is a curve on a graph that shows the changes in number of a bacterial population over time in a culture. Important points : • Not increase in size it means increase in number, increase in population. • Depends on favourable condition ( eg – temperature, pH, nutrients etc)
- 3. • This graphical representation is for heterotrophic bacteria; that means that type of bacteria who takes their food or nutrients from other sources. • The growth Curve of bacteria occurs in a geometric or exponential manner. (Means with each division cycle or generation one cell gives rise to 2 cells, then 4 cells, then 8, then 16, then 32 and so on) • The time require for formation one single generation is called generation time (G).
- 4. Phases of Bacterial Growth Curve It has been determined that in a closed system or batch culture (no food added, no wastes removed) bacteria will grow in a predictable pattern, resulting in the growth curve. This curve consists four distinct phases: • Lag phase • Exponential or log phase • Stationery phase • Death phase
- 5. Lag Phase : • Newly inoculated bacteria are adopting the new environment. So this phase is also called preparatory phase. • The bacteria required the period of time between the introduction of a microorganism into a new culture medium and the time it begins to increase exponentially, this period is called lag period. • A small group of cells that are placed in a rich nutrient medium, synthesize proteins and other necessary molecules. These cells increase in size, but no cell division occurs in the phase.
- 6. Log Phase : • This is the time when the cells are dividing by binary fission and doubling in numbers after each generation time. • The division of the bacteria is in logarithmic or exponential way. So this phase is also called exponential phase. • In case of pathogenic bacteria our body try to kill them, as they increase in number. As a result symptoms appear at this phase.
- 7. Stationery Phase : • Lack of food, nutrients and accumulation of wate products, hence growth slow down. • Reproduction rate = Death rate. • The stationary phase lasts as long until there are no nutrients left and also there is too much accumulation of waste.
- 8. Death Phase : • Acute shortage of available food. • Increase the secretion of toxins. • Number of living cells decreases exponentially. • Death rate >> Reproduction rate. • Ultimately the bacteria disappear completely from that place.