Utilization of various chitinous sources for production of mycolytic enzymes by Pantoea dispersa in bench-top fermenter

Abstract

The fermentative processing parameters (agitation, aeration, and pH) were optimized for the production of mycolytic enzymes and growth of novel marine isolate Pantoea dispersa. It was studied in a bench-top 5 l fermenter. Medium suitable for mycolytic enzymes production and growth was screened and used to optimize fermentation conditions. Monreal and Reese medium (g/l: chitin, 5.0; yeast extract, 0.5; (NH 4) 2SO 4, 1.0; MgSO 4·7H 2O, 0.3; KH 2PO 4, 1.36), served as the basal medium. Screening was carried out by a one-factor at a time optimization method. Among the four different media used, medium IV (g/l: chitin, 15; urea, 0.32; CaCl 2, 0.10; MgSO 4·7H 2O, 0.08) increased biomass and mycolytic enzymes production compared to Monreal and Reese medium. Highest mycolytic enzymes production was achieved at 72 h, however alkaline protease level was higher at 60 h. The fermentative processing parameters set up for reaching maximum response for mycolytic enzymes and biomass productions were obtained at 300 rpm agitation, 0.5 vvm aeration and without controlling the pH and dissolved oxygen (DO). The higher production was obtained in fermenter in reduced time as compared to shake flask level conditions. Different chitinous sources, such as crustacean waste chitin, solid crustacean wastes, dried fungal mycelia of Fusarium sp. and Macrophomina phaseolina were compared with commercially available sigma and matsyafed chitin, for the production of mycolytic enzymes and biomass. Acid-swollen forms of crustacean waste chitin and commercially available sigma chitin were found to be better and used for further studies.