Evaluation of Chitinase production in Serratia marcescens

Background and Objectives: Chitinase is one of the most important mycolytic enzymes with industrial significance, and produced by a number of organisms. Chitinase-producing microorganisms are reported normally eukaryotic fungi, and very few are bacteria. Production of chitinase from bacteria has distinct advantages over fungi, due to the formation of mycelia of fungi in the later phase of fermentation. In this research, we evaluated the chitinase-producing properties in bacteria isolated from shrimp pond’s sediments. Materials and Methods: Water samples and sediments were collected from shrimp aquaculture ponds in Choebdeh-Abadan. Species identification was conducted using valid identification keys, biochemical tests and PCR amplification. The pure colonies maintained on peptone glycerol agar were streaked on colloidal chitin agar medium plates and then investigated for their ability to hydrolyze and growth on chitin plates due to secretion of chitinase. Results: The appearance of the colonies obtained from the S. marcescens species was red and pink with a round shape, a smooth surface and a moderate size. Small pink bacilli under the microscope, TSI, Simon s citrate and positive VP, MR and negative indole represented the properties of S. marcescens. The 16SrRNA sequencing results also confirmed the species with 98% similarity using BLAST program in GenBank. The results of culture on colloidal chitin agar medium indicated that S. marcescens consumed chitin at a high rate, and produced a clear zone with large diameters. Conclusion: S. marcescens can feed on chitin in the shrimp shell due to the production of chitinase and thus shrimp ponds can be a suitable habitat for this strain. Since chitinase is an important enzyme in the industry, S. marcescens isolated from shrimp ponds can be used for isolation and purification of this enzyme.