Induction of mutations using gamma irradiation to improve the enzymatic metabolites production in microorganisms

BACKGROUND AND OBJECTIVES:Enzymes are biological polymers that usually were used pure or complex, in small amounts. Microorganisms such as Penicillium sp., Trichoderma sp., Aspergillus sp., Streptomyces sp. Bacillus sp. were the biological agents used for the synthesis of enzymatic metabolites (cellulase, xylanase, chitinase and pectinase, laccase, phytase and protease) which are required in agricultural industries. Natural mutation is the most important factor in the genetic changes and to create new microbial strains, but it happens at a very slow rate due to mechanisms of genome protection and genetic stability of species.MATERIALS AND METHODS:To access new microbial strains with the potential to produce diverse or more efficient metabolites, induced mutation by gamma irradiation is used to produce new mutant strains.RESULTS AND DISCUSSION:Induced mutation leaded to reduce the cost and time of screening, in studies of the secondary metabolism pathways of microbes or to produce new and more efficient metabolites needed in industries and sometimes to change the ratio of metabolites produced by microorganisms in industrial fermentation. Random and hereditary genetic mutation induction using gamma ray irradiation, screening mutants in the lab scales and optimizing the fermentation conditions of selected mutants to produce required metabolites are the common steps of obtaining strains with more enzyme production efficiency.CONCLUSION:Nuclear Science and Technology Research Institute (NSTRI) has made several achievements in the field of applying the induced mutation technique with gamma irradiation and producing more efficient microbial mutants (Trichoderma, Aspergillus and Bacillus) for the production of various hydrolytic enzymes.