Fermentation is a series of steps taken for conversion of a particular substance into its simpler form. Microbes plays a vital role in the fermentation process. It has its applications in making beer, wine bread, yogurt, and other foods. Classically fermentation is known for converting sugar to carbon dioxide and alcohol aerobically by yeast. Now, fermentation has become a well-known industrial process of making a wide variety of metabolites and biomaterials on large scale.
Fermentation is of generally of two types based upon its operation i.e. batch fermentation and continuous fermentation. In batch fermentation microbes are grown on a fixed amount of substrate and nutrients which are added at the beginning of the process. In continuous fermentation, microbes are grown continuously and the substrate is added continuously at intermittent rate and product is withdrawn periodically to achieve the desired growth rate of microbes. Continuous fermentation leads to high productivity but it has a high risk of contamination and its recovery is expensive.
Applications-Many anti-microbial drugs classified as anti-bacterial, antifungal, antiviral and anti-parasitic drugs like penicillin, cephalosporin etc. which treat microbial infections are produced by fermentation. Certain anti-tumor antibiotics are also formed by fermentation which is used for breast cancer, acute leukemia, and sarcomas etc. Some steroids are also biotransformed into useful therapeutic drugs e.g.- prednisolone is obtained from hydrocortisone by biotransformation. Certain enzymes produced by bacteria and fungi are produced by fermentation like L-glutaminase and L- asparaginase which has anti-tumor activity. Fermentation has also lead to the development of recombinant hepatitis B, DNA vaccine for HIV. Bacteria used in the manufacture of probiotics Lactobacillus and Bifidobacterium species are produced by fermentation. Diagnostic products like malaria detection kits based on ELISA method made of recombinant Plasmodium falciparum HRP-II proteins are formed by fermentation. Many secondary metabolites generally alkaloid based are manufactured by fermentation having an anti-carcinogenic and anti-microbial effect.