What is Biotechnology ? The use of organisms to make products for man Raw materials Suitable organisms Usually micro-organisms Biotechnology processes Foods, enzymes, Antibiotics, fuels Sewage treatment Water purification
Where is it used Brewing Baking Dairy Industry Pollution control Food Industry Medicine Biological detergents Immobilised enzymes
Ancient Egyptians Ancient Egyptians Noticed that when grapes were left a silvery dust appeared on them On leaving them they also noticed they began to break down and leave a liquid behind Alcohol Biotechnology been used for thousands of years but was not given the fancy name
What is that dust ? Yeast !! It is a single celled fungus It has no chlorophyll so it has to make its own food Yeast feeds on the sugar in fruit and makes alcohol
Yeast It is of great use in two major industries Brewing Baking
Baking After the yeast has been added to the flour mixture the dough is kneaded The mixture is left and we see the dough rise The yeast produces CO 2 which makes the dough rise
Baking The dough can now be baked in a hot oven
Brewing Add yeast to any fruit juice and we will see the yeast convert the sugar into alcohol water
Fermentation Glucose alcohol + Carbon Dioxide + Energy In baking the alcohol evaporates The above shows Anaerobic Respiration Little Energy produced in absence of oxygen
Beer making A very complex and series of controlled measure goes into making beer There is no involvement of grapes – so how do the yeast get food for energy The Barley grain
Malting Before the yeast can use the grain for food it must be malted The starch is converted into simple sugars the yeast can break down The barley is spread out in a large area where it is kept moist and warm and allowed to germinate Germination sees the starch being broken down into sugar
Mash The germinated grains are killed by heat to prevent the sugar being used in germination The grains are then crushed into a MASH Water is added As the sugar dissolves in the water it is sweet tasting WORT
Wort Next ? Extra sugar is added Hops can be added to give flavour Wort is boiled to kill bacteria
Fermentation The wort is cooled and yeast is added The mixture is allowed to ferment until the yeast is killed by the alcohol
Storage Stored in containers to allow it to mature It is then filtered then ………
Supplied to Consumer
Batch Processing Raw materials Nutrients fed Into vessel Reactor vessel Fermenter Microbes growing and bringing about fermentation process Micro-organisms fed in
Product formed Microbes no longer growing Products and microbes removed separately
Yeast are facultative organisms- will grow with or without oxygen In the absence of O 2 , they live by fermentation. End products are alcohol (ethanol) and CO 2 In the presence of O 2 they live by respiration. CO 2 is final product Torula yeast. Candida utilis
Conditions favoring growth of yeasts: air, sugar, acid food, liquid, wide temperature range Where yeasts are found: environments high in sugar - skins of fruits, nectar of flowers, surfaces of plants and mucous membranes of animals
Associations with humans: Some yeasts are normal flora of the oral cavity, skin, GI tract and vagina
Useful fermentations Saccharomyces cerevisiae is yeast that is used to ferment sugars to ethanol and CO 2 CO 2 is the desired end product of bread makers that leavens bread. Ethanol is the sought after end product of brewers and winemakers.
Commercial yeasts for bakers, brewers and wine makers
Harmful associations - Agents of disease in humans and other animals Candida albicans associates with humans in the mouth, intestine and vagina. It grows in most moist areas. It can cause disease under some conditions. Candida albicans budding cells and colonies
Harmful associations - Agents of disease in humans and other animals Candida causes thrush in the oral cavity, athlete’s foot, and is the most frequent cause of vaginitis in women. Candidiasis in the oral cavity (thrush) and between toes (“athlete’s foot”)
Lactic Acid Bacteria
The main bacteria used in manufacture of dairy products are commonly known as Lactic Acid Bacteria (LAB).
The bacteria utilise the lactose in the milk to produce lactic acid.
Starters are used in the manufacture of cheese.
Role of Lactic Acid
The fresh acidic flavour of unripened cheese
Important to the formation and texturising of the curd.
Produces volatile flavours
Synthesis of proteolytic and lipolytic enzymes - important in cheese ripening.
May influence micro-flora.
Most cheeses are ripened before consumption from 2 weeks for semi-hard Caerphilly to 2 years for parmesan.
Ripened by enzymes derived from rennet, starter m/orgs, non-starter m/orgs and from the milk itself.
How do you make cheese?
Normal produced from anaerobic fermentation from milk
Involves fermentation of milk (lactose) by lactic acid bacteria (streptococcus)
Milk (containing lactose) Starter culture Rennet added Soft curd Firm curd Salting Moulding and pressing Ripening and maturation
The production of cheese
Cheese is produced from Milk ________ using anaerobic
bacteria. Anaerobic bacteria respire without using
__ Oxygen ______.
The way in which cheese is made involves using a starter
_ Culture ______ which is added to the milk and left for a few
hours to ferment at a temperature of _ 37degrees ____ C. The soft
curd is then _ Salted ______, moulded and pressed to make the
Fig A : Streptococcus used to make Edam Cheese
A cultured dairy product
Soured by LAB
Role of LAB is to produce acid and flavour compounds.
Mixed culture usually added to develop different flavour profiles within the product.
Making yogurt Milk containing lactose Lactic acid bacteria added to the milk Bacteria feed off lactose in milk Lactic acid produced increases the milk acidity Milk protein caesin thickens and coagulates to produce yogurt
The production of yogurt
Yoghurt is produced from MILK using ______. These lactic acid bacteria feed on the _______ in the milk and lactic acid is produced which increases the ______ of the milk. As this occurs the milk _______, called caesin, coagulates the milk and thickens producing yogurt!!! Flavouring and colouring can then be added.
BACTERIA ACIDITY LACTOSE THICKENS
The souring of milk is a fermentation process
Fresh milk contains sugars(lactose)and some bacteria
The bacteria feed on the sugars
The lactose is converted into Lactic acid by BACTERIAL FERMENTATION
The increased acidity makes the milk turn sour
Sub Topic B…Problems with profit and waste…
WORKING WITH MICROBES
Microbes can be harmful…
Useful microbes like yeast and Lactic acid bacteria are not harmful to humans.
Some types of microbe are harmful though…
They cause diseases
Scientists studying these harmful microbes MUST take precautions to STOP them escaping and contaminating equipment….
..Sterile conditions are VITAL….
Wear lab.coats,overalls,gloves and masks where necessary.
Wash hands CAREFULLY.
Sterilise equipment and work surfaces.
No food or drinks in the lab.
Careful disposal of microbes using HIGH TEMPERATURES.
These precautions are needed in all biotechnological Processes to avoid contamination of pure cultures of other Microbes by unwanted types from the surroundings
PENICILLIN WAS DISCOVERED BECAUSE OF POOR BIOTECHNOLOGY PRECAUTIONS WHICH LED TO CONTAMINATED CULTURE PLATES IN ALEXANDER FLEMING’S LAB…..BUT OF COURSE,MOST CASES OF CONTAMINATION ARE NOT USEFUL AT ALL… THEY CAN BE VERY HARMFUL…. EG MRSA IN HOSPITALS DUE TO POOR HYGIENE PRACTICE….
Precautions during manufacturing processes are very important as well..
A particular danger can be SPORES from Bacteria and Fungi which are Resistant to normal hygiene measures
THEY CAN ONLY BE KILLED BY VERY HIGH TEMPERATURES IN AN AUTOCLAVE,OR BY CHEMICALS..
USING BACTERIA FOR DECOMPOSITION
Decay is important as it recycles raw materials and gets rid of waste at the same time.
Decay is the decomposition of ORGANIC matter by Micro-organisms
They feed on the waste to provide themselves with ENERGY.
During the process,both carbon and nitrogen are recycled
DO YOU REMEMBER THE CARBON AND NITROGEN CYCLES ?????
N 2 Nitrogen fixing bacteria in soil and nodules of plants Nitrates are made into proteins in plants NO 3 - Animals get their protein by eating Death and decay Bacteria break down the protein into nitrates NO 3 - Which can be taken back up by plants and made into proteins Denitrifying bacteria use nitrates and release nitrogen into the air Lightning and the addition of fertilisers also adds nitrates to soil Nitrogen is returned to the soil so that plants can use it to produce new proteins..
Carbon dioxide reservoir in the air Animals Decomposers Plants eating respiration respiration death death respiration photosynthesis Carbon is recycled into carbon dioxide which plants need For PHOTOSYNTHESIS
Kew Gardens compost heap… … Britains’ largest!
What do we do with our waste then ?????
Flushed away down the drains and sewers.
Cannot be emptied into the water system
Must be treated to be made safe
Micro-organisms help to make sewage harmless to the environment.
Just flush it away ?
Untreated sewage causes problems
It LOWERS the oxygen concentration of rivers
It also lowers their pH (makes acid rivers!)
Causes diseases from the poisons,and harmful micro-organisms
Such diseases include Typhoid,Polio,Dysentry and Cholera !!
So what do we do then ?
Use micro-organisms to breakdown the waste to produce products which are harmless to the environment
They do this using their ‘decaying’action
The micro organisms need LOTS of OXYGEN to do this
Why do you think this is ??
Its all to do with respiration..
Lack of oxygen means ANAEROBIC respiration
This means that the microrganisms will only partially breakdown waste
Lots of oxygen allows AEROBIC respiration
AEROBIC respiration allows the COMPLETE breakdown of the waste material
Sewage Treatment-a summary.
National and local legislation regulates the quality of water that can be returned to the environment. A range of purification steps are required to meet the targets:
Consists of three stages:
Bulk physical removal of
suspended organic matter.
Microbial degradation to lower the organic content.
Remaining organic pollutants and minerals removed.
Whats in Sewage ??
A wide variety of waste materials
Different types of micro organism feed on different types of waste
So a wide variety of Micro organisms MUST be provided so that ALL the waste can be broken down
THESE ARE SETTLEMENT TANKS WHERE OXYGEN IS ADDEDTO THE SEWAGE BY BIG ROTATING ARMS.WHAT IS THIS OXYGEN FOR ?
USEFUL PRODUCTS FROM WASTE MATERIALS
BIOGAS (usually methane) can be produced from sewage sludge and domestic refuse.
High quality PROTEIN foods from waste such as Whey(from cheese making) and fruit pulps (after juice extraction)
In this way,useless or poisonous substances are converted Into useful substances such as fuel and food…
Biogas utilisation Electrical energy Thermal energy Feeding in gas grid Biogas cleaning Biogas upgrading Cogeneration Cooking Lighting Cooling Heating Direct burning Vehicle fuel Spreading Gardening Agriculture Transport Energy crops, grass from Landscape maintenance (grass, maize, beets) Agricultural residues (manure, slurry) f e r m e n t a t i o n Bioenergy System with Liquid and Solid Feeding Storage Separation solid components become compost liquid components back to the fermentation or spreading
Profit from waste !!!
The main aim in UPGRADING waste is to convert it to more useful substances
Most commonly this involves raising the levels of PROTEIN,or increasing the ENERGY CONTENT of the waste
Just one more thing on fermentation…
Some plant material can be used to produce ETHANOL by fermentation.
Ethanol and Biogas have advantages over the use of fossil fuels such as oil and coal
The raw materials are renewable and will not run out
Burning them produces less pollution than the fossil fuels
First of all….some Bacterial Genetics
Bacteria have a chromosome which controls all of its activities
Genetic engineering allows us to transfer pieces of chromosome from different organisms into bacteria
This allows bacteria to make new substances
This process involves several steps…..
How is it done ?
Useful genes in other organisms are identified
The required gene is separated from the chromosome
The gene is inserted into the ‘host’ bacteria
The bacteria reproduces containing the new gene
Increased production of useful products results from this
THIS IS CALLED GENETIC ENGINEERING…
Genetic engineering vs. selective breeding selective genetic
Single characteristics not always possible
Very slow..depends on animals/plants with relatively long life cycles
Desired characteristic confined to one type of organism
Single characteristic can be selected
Very rapid..bacteria reproduce very quickly
Characteristic can be transferred form one organism to another
More advantages of genetic engineering..
Expensive and difficult to produce substances can be made cheaply and easily eg……..
Insulin for Diabetes
Antibiotics such as Penicillin
Vaccines for the control of diseases
This is how its done………
Genetic Engineering First, the nucleus of human cells are burst Human cell Nucleus
Genetic Engineering The chromosomes are cut up into small fragments and the required gene identified. Chromosome fragments Fragment containing required gene
Genetic Engineering Next the fragments are spread out and the required one isolated. Segment with required gene
Genetic Engineering Cytoplasm Bacterial chromosome Bacterial cell wall Plasmid Structure of a typical bacterium
Genetic Engineering Plasmid Plasmids are loops of DNA separate from the main chromosome .
Genetic Engineering By using special enzymes, we can make a cut in the plasmid DNA Cut here
Next, we introduce the prepared HUMAN gene to the mixture. If all goes according to plan, the human gene will fit into the cut in the plasmid Prepared human gene
Genetic Engineering PLASMIDS ARE INSERTED INTO THE BACTERIA
Genetic Engineering Agar containing nutrients Colonies growing from single bacteria containing the plasmids with the human gene
Genetic Engineering These colonies will have the correct plasmid to produce the product from the human gene. Cells from this colony will be grown on a large scale and the medium analysed for the presence of the product from the human gene, eg Insulin
The need for Insulin is increasing…
People are living longer
Populations are increasing
Diabetes often occurs at middle/old age
Unhealthy lifestyles contribute to diabetes
Better medical treatments mean that people are living longer
So what's the problem then ?
Purifying Insulin from the pancreas of slaughtered cattle and pigs is slow and expensive.
Animal Insulin is not as effective as Human insulin.
Some people are allergic to animal Insulin
Many diabetics object to the use of a product from slaughtered animals…
And the solution ?
The insulin produced from bacteria which have been genetically altered is pure Human insulin
Its production is quick and inexpensive
It has non of the physiological and ethical problems associated with the use of cattle or pig insulin
There are dangers involved with genetic engineering.It involves Creating new strains of bacteria which MIGHT prove harmful To animals and plants……an ethical dilemma..
Contain enzymes produced by bacteria
Many of the stains on clothes are Proteins(blood,gravy,grass,etc)
The enzymes break down and digest proteins
They work at relatively low temperatures
This saves energy and money
Disadvantages of Batch Processing
Slow and Expensive….Fermenter has to be cleaned and sterilised between each product batch.
Enzymes or micro-organisms cannot be recovered for use again at the end of each batch every time.
Continuous flow processing solves these problems by relying on..
ENZYME IMMOBILISATION TECHNIQUES
Restricts the movement of Enzymes or cells
Usually by attaching them to beads of jelly or other carriers
Keeps the enzymes/cells separate from the product
This results in increased productivity and reduced costs compared to batch processing
Chemicals which prevent the growth of micro-organisms.
There are many different diseases caused by bacteria.
Different bacteria are affected by different antibiotics
One antibiotic may only work against certain types of bacteria
A range of different antibiotics is needed for the treatment Of bacterial diseases
Production of antibiotics, most notably penicillin and the beta lactam antibiotics are produced by Penicillium molds The penicillin is secreted by the mould and collected from the Nutrient jelly..