Fermentation is the process used to manufacture antibiotics, foods and drinks. It mainly involves the use microorganisms. It is a modern and a very useful technique. This process is used commercially across the globe to ferment products such as yogurt, cheese, bread, beer and various other products.
Yeast is added on to a sugary juice, like the grape juice, in an airtight container. The cap is attached with an air trap which allows the carbon dioxide to exit the container and does not allow the oxygen to enter. The yeast respires anaerobically. Once there is excess ethanol in the container, the yeast cells die, forming the beer. This is then extracted and mixed.
Yeast is added into warm water and flour is added. The mixture is kneaded and put on rest. During this period it is cut off of air and the yeast respires anaerobically producing ethanol and carbon dioxide. Sugar may be added to provide it the nutrients it needs for respiring. The enzymes in the flour break down the glucose, which is the reducing sugar, and converts it into energy, ethanol and carbon dioxide. The carbon dioxide bubbles forming helps the dough to rise. When put in oven the bubbles rise and the ethanol evaporates. Once cooked, this forms the bread.
A fermentor is a cylinder which is used for fermentation of antibodies, foods and drinks. It is also called a bioreactor. The fermentor may also be called either a batch fermentor or an industrial fermentor depending on its use and its product. The fermentor has various tubes going into and out of it providing air and nutrients as well as acids and alkalis for maintaining pH. The cylinders are computerized and are maintained by the use of probes which are connected to the computers. The microorganism which is required for a specific product is placed in the fermentor in the bottom of a liquid called a broth. The solution is stirred by the stirrers which helps in fermentation. The following factors show how microorganisms are taken care of for producing higher yields of antibodies or food like cheese or yogurt:
- The fermentation process produces heat energy which raises the temperature. This could kill the microorganism present in the fermentor. To prevent this a water jacket is present around the fermentor which has cold water flowing through it. This maintains the temperature for the microorganism to grow and reproduce in which results in a higher yield.
- Acids and Alkalis are added in to the fermentor which maintains the pH level to the optimum value. The acids and alkalis are added through a specific tube.
- Filtered air is sent into the fermentor so that the microorganism present in it can respire aerobically and would grow and reproduce. The air is filtered so that any microorganism present in the air does not flow into the fermentor and contaminate the process.
- Nutrients are constantly provided to the bacteria so that it can respire and grow and reproduce efficiently.
- Temperature indicators and pH indicators are present in the fermentor which helps in finding out the pH and the temperature of the broth.
- The stirrers stirs the broth so that the microorganisms remain suspended in the nutrients and respire effectively and reproduce. If there were no stirrers, then the microorganisms would have remained in the bottom and be cut off of the nutrient. This also helps in maintain the temperature of the broth.
- After the products are produced it is sent through the outlet pipe and the microorganisms are cleared out. Steam is passed into the fermentor to sterilize it and the bioreactor is then again used.
All the above factors are necessary to maintain and are essential for the high yield. By this we mean that such as if a bacteria is used to produce an antibiotic then these factors are necessary to maintain so that the bacteria effectively grow and reproduce. If the process is perfect then this produces a higher yield of antibiotic.
Fermentation of Antibiotic
Antibiotics are fermented by the bioreactors. One of the famous antibiotics fermented is penicillin from the bacteria Penicillium. The process starts the same. The bacteria is kept in the fermentor for several days, probably more than 2 weeks! The conditions inside the bioreactors are kept constant for the best growth and reproduction of the bacteria. Once the bacteria is ready for harvesting, the bacteria is sent out of the bioreactor through the outlet pipe and the fluid, which the bacteria releases during the process, is collected. After a number of chemical processes the extracted penicillin is “cleaned” or “purified” from the waste products of the bacteria and is crystallized. The antibiotic can then be stored in a powder form.
Single Cell Proteins
Single cell proteins (SCPs) are artificial food which are formed from the microorganisms. The microorganisms are either genetically modified or are set in certain conditions so that it produces protein substances. These are used to form single cell proteins which are then used as food. This was intended to be used to end the scarcity of food. But today most of the single cell proteins are used to feed animals and only few are used to feed humans. The single cell proteins are rich in proteins and can be used to replace the use of meat in diet.
This is kind of an effective way of feeding people. This is because using natural meat means that this meat is produced from the food chain. By this I mean that the cow feeds on grass, the biomass is decreased as it travels into the cow, and when the meat from the cow is consumed by humans then the biomass is further decreased. The use of SCPs provide a lot of energy. This much energy is provided without the loss of biomass in the microorganisms.
Mycoprotein is an example of single cell protein. “Myco” means “fungus” as in mycology. The mycoprotein can be used to feed humans instead of meat or chicken or even mutton. It has rich amount of proteins and minerals in it. However it is not fermented in a normal bioreactor. A special, long bioreactor is used which forms a loop around itself. This loop fermentor moves the broth around the bioreactor by the help of filtered air compressing into the bioreactor. The material harvested is odorless and colorless and tasteless. Flavorings and colors is added artificially to form its taste exactly like meat.