Studies on Optimization and Characterization in Effective Production of Pullulan and Bio Film Formation

Abstract

Pullulan is a well-known extra cellular polysaccharide produced by yeast-like fungus Aureobasidium pullulans (A. pullulans). As it has a wide range of commercial and industrial applications with high demand, the investigations on the production of pullulan with Aureobasidium pullulans have been emphasized in the present work objective. The effect of growth parameters such as, initial pH and temperature were optimized in order to maximize the growth of A. pullulans and pullulan production. The initial pH of the fermentation medium was varied between acidic to base natures and found the optimized value. Incubation temperature significantly affects the morphology of an organism, inturn it will affect the synthesis of pullulan. And hence, the optimum temperature is predicted to fix essential condition for the fermentation. Similarly, the required fermentation time for pullulan formation was optimized towards higher productivity. In the continuation of optimization processes the media composition for pullulan fermentation also optimized using Response Surface Methodology. Sucrose, Yeast extract, Ammonium Sulphate, K2HPO4, NaCl, media components are used and also optimized. All the optimized parameters are yielded maximum cellmass and pullulan concentration. newlineIn order to economize the process, fermentation was carried out with wide varieties of carbon sources. Crude substrates such as, Cassava peel, Corn Cob, Potato Peel, Banana Peel were investigated. All the crude carbon sources support the A. pullulans growth and pullulan production. The highest concentration of pullulan was obtained for the crude substrate of Corn Cob hydrosylate. The various ranges of initial Corn Cob concentration effect were studied. Characterization of exo-polysaccharide was carried out using IR spectroscopy. Fourier transform infrared (FTIR) spectra were recorded with a Perkin Elmer-Spectrum RX1 spectrometer (32 scans; resolution, 4 cm-1) over KBr pellet.