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

CAVELLO, IVANA; CAVALITTO, SEBASTIÁN FERNANDO; HOURS, ROQUE ALBERTO

APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY

HUMANA PRESS INC

Lugar: Oregon; Año: 2012 vol. 167 p. 945 - 958

0273-2289

Paecilomyces lilacinus (LPS 876) efficiently degraded keratin in chicken featherduring submerged cultivation producing extracellular proteases. Characterization of crudeprotease activity was done including its compatibility in commercial detergents. OptimumpH and temperature were 10.0 and 60 °C, respectively. Protease activity was enhanced byCa2+ but was strongly inhibited by PMSF and by Hg2+ suggesting the presence of thioldependentserine proteases. The crude protease showed extreme stability toward non-ionic(Tween 20, Tween 85, and Triton X-100) and anionic (SDS) surfactants, and relativestability toward oxidizing agent (H2O2 and sodium perborate). In addition, it showedexcellent stability and compatibility with various solid and liquid commercial detergentsfrom 30 to 50 °C. The enzyme preparation retained more than 95% of its initial activity withsolid detergents (Ariel? and Drive?) and 97% of its original activity with a liquiddetergent (Ace?) after pre-incubation at 40 °C. The protective effect of polyols (propyleneglycol, PEG 4000, and glycerol) on the heat inactivation was also examined and thebest results were obtained with glycerol from 50 to 60 °C. Considering its promisingproperties, P. lilacinus enzymatic preparation may be considered as a candidate foruse in biotechnological processes (i.e., as detergent additive) and in the processing ofkeratinous wastes.