DETERGENT COMPATIBLE COLD-ACTIVE ALKALINE AMYLASES FROM CLAVISPORA LUSITANIAE CB13

Abstract

After two stages of screening, five environment isolates of yeasts showing amylolytic activity at alkaline pH and residual activity at cold temperatures were isolated from rotten vegetables. Based on pH and temperature robustness, amylases from CB13 were selected for further characterization. The enzymes from this yeast-isolate showed optimum activity at pH 11 and temperature 40oC, 42 % residual activity at 4oC, no dependence on Ca2+ for activity and stability, resistance to EDTA and SDS, and amplification in activity in presence of Mn2+ and Co2+. The amylolytic activity was thermostable showing retention of 50% of optimum activity after boiling for 30 min. The enzymes retained nearly 80% of activity after exposing to various detergent components, and also to commercially available laundry detergents for 2h. The morphological, physiological and molecular characterization of the isolate CB13 led to its identification as Clavispora lusitaniae. This is the first report on the screening of detergent compatible α-amylase with residual cold-activity from yeast isolated from rotten vegetables.