Wednesday, September 07, 2005
BIOLOGY - Biotechnology
BIOTECHNOLOGY! (our favourite!)
Definition:
Biotechnology is the use of living organisms and their products for the modification human health or human environment.
ANCIENT
Bread-making
* makes use of floor and yeast
* the enzyme amylase converts starch to sugar
* due to lack of oxygen, yeast respires anaerobically and converts the sugar to carbon dioxide and alcohol
* the carbon dioxide causes the bread to rise while the alcohol is driven off by baking, but also contributes to the unique taste of bread
Wine-making
* makes use of yeast and sugar (from grapes or barley or etc)
* yeast respires anaerobically to convert the sugar to alcohol and carbon dioxide
* Japanese sake produced from fermentation of rice
Yoghurt
*makes use of bacteria
*ferment milk with lactobacillus bulgaricus and streptococcus thermophilus
*streptococcus removes the oxygen, causing anaerobic respiration
*lactobacillus then converts the lactose to lactic acid
*lactic acid causes milk protein to curdle. and taada. you have yoghurt. whoop dee.
Cheese
*makes use of bacteria and fungi
*ferment milk with ... WELL IT'S THE SAME THING AS YOGHURT ACTUALLY.
*but then after you get the nice curdled milk proteins...
*the curdled milk proteins together with the fats in milk are removed and acted upon by a mixture of bacteria and fungi.
*different bacteria and fungi give you different cheese
*mm-mmm.
NON-ANCIENT! aka... er... modern?
Single-cell protein
*use of microorganisms to provide food for animals
--> Why use it? well. because...
1) there's a whole variety of substrates for you to exploit at a low commerical cost
2) rapid growth of microorganisms
3) high protein content. mm. how nutritious
4) easily manipultaed
5) there's the technology for it
--> Why people don't eat it?
1) tasteless. people aren't very willing to eat tasteless bacteria-made food. I mean. How would you like it if you knew that your food was synthetically made with tiny little invisible-to-the-eye microorganisms?
2) risk of contamination. gaspes.
3) it's very hard to keep it in a nice and sterile condition
--> Some very nice examples:
1) Cheese making produces whey( a mixture of protein and lactose) as waste product. with a bit of tweaking here and there by yeast, it can be converted into high-grade proteins and vitamins. Yum yum. They are then used to feed cattle.
2) In oil distillation, there is a waxy substance produced as waste product. Yeast is used to act on it and its... converted to animal feed. Erm. Say ewww??
Bovine somatotrophin using recomibanant gene technique
The hormone BST can be used to induce cows to give more milk. In short, the BST gene is inserted into E. Coli, E. Coli is cloned, E. Coli produces a great quantity of BST, BST is extracted, BST is injected into cow, Cow makes more milk. Moo.
However, there are of course very bad problems with using it:
1) There may be a mastitis infection in cow's udder. And the cow will be more suceptible to diseases.
2) Cow's immunity system weakened
3) Consumer may have increased BST as there may be residue of the hormone in the milk. As they drink it, the hormone will then accumulate.
4) Cows need to eat more
5) There is not such a great demand for milk in the west
Biosensors
Biosensors are sensors which contain a biological component e.g. antibody or enzyme.
Examples:
-Using the enzyme glucose oxidase to check glucose level in blood
-Check contamination level in food by using biosensors to detect microorganisms
Production of Penicillin
-Made using a closed fermenter
-26 degrees celsius + pH 5/6 + sterile air + nutrient broth (lactose) + penicillium
-as the growth of the fungi slows down, Penicillin is formed
-nutrient broth with penicillin is extracted via crystallisation
Which brings us to ...FERMENTERS. (:!
(hahahahahahaha. ziwei is now going crazy.)
Aqueous fermentation is when the fermention is of a substrate that has high water content. This is done using fermenters!
Closed/batch fermenter
- The batch germenter is a closed fermenter. The substrate is put into the nutrient broth and then left there to ferment. During the fermentation, nothing is put in or taken away, except the venting of waste gases.
-During a closed fermentation, environmental factors are constantly changing although temperate is controlled. Expotential growth only lasts for a short period of time.
Advantages
1) The vessel is versatile, so it can be used for different processes at different times, allowing the manufacturer to meet the market's demands.
2) It is easy to set up and control the environmental factors.
3) If a culture is contaminated, only one batch will be lost, minimizing the manufacturer's costs.
Open/continuous fermenter
-In a continuous fermenter, nutrients are continually being added to balance the ones that are used up. Thus, expotential growth lasts for a longer period of time.
-It is important for the environmental factors to be constant, namely pH, oxygen level, concentration of nutrients and accumulation of products.
Advantages
1) a smaller vessel is needed since the production is more productive, what with the microorganisms being in constant expotential growth
2) it can give greater production --> more cash for the manufacturer
Disadvantages
1) it is very difficult to keep all the environmental factors constant, and the system might be unbalanced. in the case that the continuous fermenter breaks down, there will be a lot of waste and thus a lot of money lost.
2) practical problems might pop up, such as foaming, clumping of cells and microbial growth blocking the inlets
Parts of a fermenter
-Cylindrical tank to... hold the nutrient broth and substrates
-Inlets for air to enter, and outlets for waste air to be vented out
-pH probe: makes sure that production is at optimum pH as enzymes are protein in nature and thus sensitive to the acidity and alkalinity
-temperature probe: makes sure that production is at optimum temperature. Too cold: enzymes inactive. Too hot: enzyme structure changes, enzymes denatured.
-aeration system (stirrer and sparger): introduction of air so that the microorganisms can respire, and to expose the substrates to more nutrient medium.
-water jacket: for temperature control
-inlet for acid/alkali: for pH control
...did I miss out anything?! *PANIC* -ziwei
Definition:
Biotechnology is the use of living organisms and their products for the modification human health or human environment.
ANCIENT
Bread-making
* makes use of floor and yeast
* the enzyme amylase converts starch to sugar
* due to lack of oxygen, yeast respires anaerobically and converts the sugar to carbon dioxide and alcohol
* the carbon dioxide causes the bread to rise while the alcohol is driven off by baking, but also contributes to the unique taste of bread
Wine-making
* makes use of yeast and sugar (from grapes or barley or etc)
* yeast respires anaerobically to convert the sugar to alcohol and carbon dioxide
* Japanese sake produced from fermentation of rice
Yoghurt
*makes use of bacteria
*ferment milk with lactobacillus bulgaricus and streptococcus thermophilus
*streptococcus removes the oxygen, causing anaerobic respiration
*lactobacillus then converts the lactose to lactic acid
*lactic acid causes milk protein to curdle. and taada. you have yoghurt. whoop dee.
Cheese
*makes use of bacteria and fungi
*ferment milk with ... WELL IT'S THE SAME THING AS YOGHURT ACTUALLY.
*but then after you get the nice curdled milk proteins...
*the curdled milk proteins together with the fats in milk are removed and acted upon by a mixture of bacteria and fungi.
*different bacteria and fungi give you different cheese
*mm-mmm.
NON-ANCIENT! aka... er... modern?
Single-cell protein
*use of microorganisms to provide food for animals
--> Why use it? well. because...
1) there's a whole variety of substrates for you to exploit at a low commerical cost
2) rapid growth of microorganisms
3) high protein content. mm. how nutritious
4) easily manipultaed
5) there's the technology for it
--> Why people don't eat it?
1) tasteless. people aren't very willing to eat tasteless bacteria-made food. I mean. How would you like it if you knew that your food was synthetically made with tiny little invisible-to-the-eye microorganisms?
2) risk of contamination. gaspes.
3) it's very hard to keep it in a nice and sterile condition
--> Some very nice examples:
1) Cheese making produces whey( a mixture of protein and lactose) as waste product. with a bit of tweaking here and there by yeast, it can be converted into high-grade proteins and vitamins. Yum yum. They are then used to feed cattle.
2) In oil distillation, there is a waxy substance produced as waste product. Yeast is used to act on it and its... converted to animal feed. Erm. Say ewww??
Bovine somatotrophin using recomibanant gene technique
The hormone BST can be used to induce cows to give more milk. In short, the BST gene is inserted into E. Coli, E. Coli is cloned, E. Coli produces a great quantity of BST, BST is extracted, BST is injected into cow, Cow makes more milk. Moo.
However, there are of course very bad problems with using it:
1) There may be a mastitis infection in cow's udder. And the cow will be more suceptible to diseases.
2) Cow's immunity system weakened
3) Consumer may have increased BST as there may be residue of the hormone in the milk. As they drink it, the hormone will then accumulate.
4) Cows need to eat more
5) There is not such a great demand for milk in the west
Biosensors
Biosensors are sensors which contain a biological component e.g. antibody or enzyme.
Examples:
-Using the enzyme glucose oxidase to check glucose level in blood
-Check contamination level in food by using biosensors to detect microorganisms
Production of Penicillin
-Made using a closed fermenter
-26 degrees celsius + pH 5/6 + sterile air + nutrient broth (lactose) + penicillium
-as the growth of the fungi slows down, Penicillin is formed
-nutrient broth with penicillin is extracted via crystallisation
Which brings us to ...FERMENTERS. (:!
(hahahahahahaha. ziwei is now going crazy.)
Aqueous fermentation is when the fermention is of a substrate that has high water content. This is done using fermenters!
Closed/batch fermenter
- The batch germenter is a closed fermenter. The substrate is put into the nutrient broth and then left there to ferment. During the fermentation, nothing is put in or taken away, except the venting of waste gases.
-During a closed fermentation, environmental factors are constantly changing although temperate is controlled. Expotential growth only lasts for a short period of time.
Advantages
1) The vessel is versatile, so it can be used for different processes at different times, allowing the manufacturer to meet the market's demands.
2) It is easy to set up and control the environmental factors.
3) If a culture is contaminated, only one batch will be lost, minimizing the manufacturer's costs.
Open/continuous fermenter
-In a continuous fermenter, nutrients are continually being added to balance the ones that are used up. Thus, expotential growth lasts for a longer period of time.
-It is important for the environmental factors to be constant, namely pH, oxygen level, concentration of nutrients and accumulation of products.
Advantages
1) a smaller vessel is needed since the production is more productive, what with the microorganisms being in constant expotential growth
2) it can give greater production --> more cash for the manufacturer
Disadvantages
1) it is very difficult to keep all the environmental factors constant, and the system might be unbalanced. in the case that the continuous fermenter breaks down, there will be a lot of waste and thus a lot of money lost.
2) practical problems might pop up, such as foaming, clumping of cells and microbial growth blocking the inlets
Parts of a fermenter
-Cylindrical tank to... hold the nutrient broth and substrates
-Inlets for air to enter, and outlets for waste air to be vented out
-pH probe: makes sure that production is at optimum pH as enzymes are protein in nature and thus sensitive to the acidity and alkalinity
-temperature probe: makes sure that production is at optimum temperature. Too cold: enzymes inactive. Too hot: enzyme structure changes, enzymes denatured.
-aeration system (stirrer and sparger): introduction of air so that the microorganisms can respire, and to expose the substrates to more nutrient medium.
-water jacket: for temperature control
-inlet for acid/alkali: for pH control
...did I miss out anything?! *PANIC* -ziwei
# we mugged! @ 12:47 AM 
