Biodegradation of a keratin waste and the concomitant production of detergent stable serine proteases from Paecilomyces lilacinus

CAVELLO, I.A.; CAVALITTO, S.F.; HOURS, R.A.

Trivandrum

Congreso; International Conference on New Horizons in Biotechnology (NHBT); 2011

National Institute for Interdisciplinary Science and Technology (NIIST)

Paecilomyces lilacinus strain LPS # 876, isolated from alkaline soils from Buenos Aires Province, (Argentine) efficiently degraded feather keratin during submerged cultivations, producing extracellular proteases. The present study describes the characterization of crude protease and its compatibility in commercial detergents. The optimum pH and temperature for proteolytic activity were 10.0 and 60°C, respectively. Protease activity was enhanced in the presence of 1mM metal ions, such as Ca 2+ and Mg2+ but was strongly inhibited by PMSF, a serine protease inhibitor and by Hg 2+ suggesting the presence of thiol-dependent serine proteases. The crude protease showed extreme stability toward non-ionic (5% Tween 20; 5% Tween 85 and 5% Triton -100) and anionic (1% SDS) surfactants, and relative stability toward oxidizing agent (1 to 3% of H2O2 and 1 to 3% of Sodium perborate) . In addition, it showed excellent stability and compatibility with various solid (7mg/ml) and liquid (1%v/v) detergent at temperature from 30 to 50°. In presence of solid detergent, the enzyme preparation retained more than 95% of it initial activity after pre-incubation for 1 h at 40°C with Ariel and Drive, followed by Skip and Ala matic. With liquid detergent, the enzyme preparation retained 97% of it original activity after pre-incubation for 1 h at 40°C with Ace. The protective effect of polyhydric alcohol, such a propylene glycol, PEG 4000 and glycerol on the heat inactivation were also examined. Among the polyols examined, the best results were obtained with glycerol from 50° to 60° C. Considering it promising properties P. lilacinus enzymatic preparation may be considered a potential candidate for future use in biotechnological processes, particularly in detergent and in the processing of poultry wastes, particularly keratinous wastes.