Many processes in industry require micro organisms. For example, they are essential in decomposition of waste of animal and plant. Also nitrogen is recycled in ecosystem with micro organisms. Apart from these, micro organisms play an important role in food production and water treatment. Fermentation is a process where micro organisms are most important. Here, carbohydrates like sugar are turned into alcohol or acid with the help of treatment with micro organisms. Many of food items are produced using micro organism like cheese, curd, beer, wine, butter and bread. (Lowry, Rosebrough, Farr, & Randall, 1951)
Saccharomyces cerevisiae is the most common yeast used in the production of beer. It is also known as baker's yeast. Barley grain or wheat grain is dried and then crushed to mix with hot water and yeast for fermentation process. In the process, sugar is converted into alcohol and carbon dioxide. Then beer is separated from the mixture after 5 days, matured and used for consumption. (Lowry, Rosebrough, Farr, & Randall, 1951)
For wine too, fermentation process is used, where sugar is extracted from crushed grapes and yeast is mixed with it for fermentation which converts sugar into alcohol. (Lowry, Rosebrough, Farr, & Randall, 1951)
Some drinks contain pro-biotic bacteria, like yoghurt based drinks, which gives health benefits to the host. The presence of Lactobacillus bulgaricus which is a bacterial strain translates the lactose sugar into lactic acid which causes the milk to clout by lowering the pH which creates the texture and taste of curd. (Lowry, Rosebrough, Farr, & Randall, 1951)
Application of Microbes in Waste Treatment Industry:
Use of micro organisms in sewage and waste water treatment has been carried out since long time. Use of micro organisms which grow naturally in sewage treatment systems are commonly used in the usual approach of sewage treatment. One would find most of the sewage treatment plants are huge in size as the treatment of sewage by micro organisms require large amount of oxygen, for which it requires good amount of room. Developments of air lift fermenters and tubular loop reactors have been made for improving the efficiency of the plant. These two have better efficiency for oxygen transfer. USA and Germany have tried Aeration by pure oxygen. There are many companies now who market sewage treatment plants which uses pure oxygen. (Meevootisom, Somsuk, Prajaktham, & Flegel, 1983)
Application of Environmental Microbes in Agriculture:
The soil health has become degraded due to excessive usage of chemical fertilizers in conventional agriculture approach. Due to this the capacity of soil to retain soil carbon has gone down. Due to soil structural degradation, the capacity of soil to store nutrients and water has gone down. Because of this, it affects the plant growth and water can become adversely saline. Plant's health and quality of soil can be rapidly restored by application of microbes and substrate of carbon. A spray applicator is used to spray liquid microbes. Generally, 100 L per hectare of mixture of 10 parts of water with one part microbial concentration is used in agricultural soil. There are other nutrients that can be mixed along with this mixture like humates, compost teas, liquid seaweed, etc for soil benefits. (Meevootisom, Somsuk, Prajaktham, & Flegel, 1983)
Microbial Production of Primary Metabolites:
There is a significant contribution of Microbial production of primary metabolites to quality of life. Valuable products such as amino acids, solvents, organic acids, vitamins etc can be produced by micro organisms that are growing on carbon sources, through fermentation. Food's nutritive value can be increased and flavor can be added when such products are added to food. (Ohashi, Katsuta, Nagashima, Kamei, & Yano,1989)
Vitamins:
Vitamin B2, also known as Riboflavin can be produced either by fermentation or by chemical synthesis. Vitamin B2 produced by fermentation is generally used in animal feed and the one produced by chemical synthesis is utilized for pharmaceutical and food.
Fermentation is also used to produce Vitamin B12. Propionibacterium shermanii and
Pseudomonas denitrificans are the types of bacteria used by the industry to produce Vitamin B12. The key to the P. shermanii fermentation is apparently avoidance of feedback repression by vitamin B12. the early stage is conducted in absence of the precursor 5,6-dimethylbenzimidazole under the anaerobic conditions. Vitamin B 12 syntheses are prevented by these conditions and accumulation of the intermediate, cobinamide is allowed. Then, dimethylbenzimidazole is added while turning the air on which converts cobinamide to vitamin. (Ohashi, Katsuta, Nagashima, Kamei, & Yano,1989)
Organic Acids
For commercial production of organic acid, Filamentous fungi have used extensively. Mycelial fungi have been majorly used to produce citric acid. Estimated figure of production is 100000t of citric acid per year. Aspergilhts niger or its mutants are used for commercial process. There are number of processes used for the production of citric acid. Some processes deployed are Koji fermentation process, the liquid culture shallow pan process, and the submerged fermentation process. Citric acid is used as flavor enhancing ingredient and as an acidifying material. It also helps to slow down the rancidity in oils and fats as an antioxidant. Also its used as stabilizers in various foods. Its salts are also used in jellies and jams as buffers. Out of the total supply of citric acid, pharma industry uses 16%. (Ohashi, Katsuta, Nagashima, Kamei, & Yano,1989)
Microbial Production of Secondary Metabolites:
Microbial secondary metabolites are very important for health of humans. They are low molecular mass product and of utmost importance for the production of cultures. Some examples of Microbial secondary metabolites would be cholesterol lowering drugs, antibiotics, anti tumor agents and some other drugs. They are not of ususal structure and are formed at a very late growth phase of the production of microorganisms. The synthesis of Microbial secondary metabolites can be affected to a great extent by making changes in the concentration and type of nutrients formulating the culture media. To explain the pessimistic carbon catabolite effects on secondary metabolite production, there are various mechanisms in bacteria and fungi described. It is useful to have its knowledge and manipulation to set different conditions for fermentation and strain improvement. (Savidge & Cole, 1975)
Production of Antibiotics by Microorganisms:
There are number of microorganisms that produce antibiotics and restrain the production of other microorganisms at a very low concentration. Because of this, the application of antibiotics have been extensive in chemotherapy, food preservation, plant pathology, as research tools in biochemistry and molecular biology and veterinary medicine. There are more than 100 antibiotics produced commercially through the process of microbial fermentation out of 7000 currently present antibiotics. Alexander Fleming discovered the first antibiotic in the year 1929 known as penicillin. This was produced on an extensive scale in 1940 using the cultures of Penicillium notatum. (Savidge & Cole, 1975)
Production of Fatty Acids by Microorganisms:
Microbial oxidants that produce fatty acids from alkenes have gained attention as surfactants. Microorganisms construct complex fatty acids that contain OH groups and alkyl branches apart from the straight-chain acids. Some of these complex acids are surfactants, like corynomucolic acids. (Savidge & Cole, 1975)
Production of Phospholipids by Microorganisms:
Phospholipids are major components of microbial membrane. The level of phospholipids increases to a great extent when certain CxHy degrading bacteria or yeasts are grown on alkene substrates. Phospholipids have potent surfactants when grown from hexadecane grown Acineto bacter sp. Phospholipids are responsible for wetting elemental sulphur necessary for growth are produced from Thiobacillus thiooxidans. (Senthilvel & Pai, 1998)
Importance of recombinant DNA technology in microbial biotechnology:
One form of genetically engineered DNA is Recombinant DNA. What is done here is one strand of DNA is taken from an organism and this strand is inserted or combined with DNA of organism from other species. Here an artificial DNA is created by combining DNA of two different species, which would not occur together normally. This type of DNA does not occur through processes with cell or ribosome, but such are engineered exclusively and hence it differs from genetic recombination. (Senthilvel & Pai, 1998)
This technology has been gaining lot of importance as the knowledge and awareness about it is spreading. It is becoming more and more widely used in areas of cure for genetic diseases and for agricultural purposes as such land is getting reduced. Some areas where Recombinant DNA technology will have an impact are:
For better yield of crops in conditions of drought and heat.
For research on Recombinant Vaccines for diseases like Hepatitis B
Prevention and cure of sickle cell anemia
For research on prevention and remedy of cystic fibrosis
For production and growth of clotting factors
Production of insulin
Production of recombinant pharmaceuticals
Plants that produce their own insecticides
Germ line and somatic gene therapy (Senthilvel & Pai, 1998)
Conclusion:
All sectors of concern to mankind are greatly impacted by the activities of microorganisms. From the above discussions we can find uses of microorganisms in all sectors like pharma industry, food, waste treatment, agriculture and environment. The importance, scope and impact of microbiology has increased by manifolds. Lot of efforts have been put to save environment and researches have been carried out and are still going on to save environment in a green manner with the use of microorganisms. These efforts are carried out worldwide. (Eric, 1979)
