Thirunavukarasu_2016_Int.Biodeterior.Biodegradation_110_99

The yeast, Cryptococcus sp. MTCC 5455 was grown on various agro-industrial residues for the production of lipase. A maximum lipase activity of 75319Ug dry substrate-1 (Ugds-1) and a biomass of 1035mggds-1 was obtained at 25C and 120h using cottonseed oil cake with 71% moisture content and 30% (v/w) inoculum. The recovery of the enzyme was increased by 14.1%, when the fermented substrate was extracted in 2mM CaCl2.2H2O solution. The crude enzyme partially purified by (NH4)2SO4 precipitation showed a major 22kDa protein on SDS-PAGE. The enzyme has good potential for hydrolysis of poly(butylene succinate) (PBS) and poly(butylene succinate-co-butylene adipate) (PBSA) and complete degradation of the polymeric films were observed at 72h and 16h respectively. The degradation was evaluated by Fourier transform infrared (FTIR) and 1H NMR spectroscopy. The complete hydrolysis of polymers by Cryptococcus sp. lipase makes the process ideal and also serves as a baseline for its exploitation in polymer degradation.