SCREENING OF KERATINOLYTIC BACTERIA FROM PATAGONIAN MERINO WOOL WITH POTENTIAL FOR TEXTILE PROCESSES

MARTÍN IGLESIAS; CYNTHIA SEQUEIROS; SEBASTIÁN GARCÍA; NELDA LILA OLIVERA

Rosario

Congreso; L Reunión SAIB 2014; 2014

SAIB

Keratinolytic enzymes attenuate wool fiber scales imparting shrink-resistance, softness and whiteness to the wool. Our aim was to isolate native bacteria from patagonian Merino wool and assess their wool keratinase activity regarding the potential for shrink-proofing process. For bacterial isolation, wool samples were divided in two sub-samples, one of them was suspended is saline solution and plated on Skim milk (SM) and selective actinomycete agar. The second sub-sample was incubated in mineral salt medium with wool as a sole source of carbon and nitrogen, and then plated on SM. To detect the best protease producers, spots of culture supernatants were plated on SM and the diameter of the digestion halos measured. Keratinase activity was assessed using milled wool as substrate. One unit of enzyme activity (UE) was defined as the amount of enzyme which liberates 1 μmol tyrosine/min. From 135 isolates, 66 showed proteolytic activity. Seventeen strong protease producers were selected to test keratinase activity. Nine strains hydrolyzed wool proteins producing about 0,05 to 0,01 UE/ml of supernatant. Wool keratin shows high recalcitrance to proteolytic degradation due to the tight packing of its protein chains. The capability of these isolates to produce wool keratinolytic enzymes makes them interesting candidates for the development of shrink-proofing treatments for the wool industry