Goan mangrove yeast: a source of therapeutic enzyme L-asparaginase

Abstract

Mangrove forests support robust microorganisms due to their changing temperature and salinity conditions. Tropical yeasts isolated from such habitats have the potential to produce clinically significant enzymes like L-asparaginase. L-asparaginase converts L-asparagine to L-aspartate and ammonia. In this study, 14 tropical yeasts were isolated from mangrove sediments collected from Madkai, Goa, India. From these, on screening with two different indicator dyes phenol red and bromothymol blue, five isolates were positive for L-asparaginase enzyme as indicated by rapid plate assay technique. Isolate having highest enzyme activity was identified as belonging to genus Cyberlindnera. The study of effect of physical parameters on enzyme production revealed optimal incubation time of 48 h, pH of medium 7.0 and incubation temperature of 28 degrees C. Evaluation of carbon and nitrogen sources indicated L-asparagine as sole nitrogen source and glucose as carbon source achieved maximum enzyme production. L-Asparaginase activity of isolate GULAMMS8 under optimal medium composition and parameter conditions that are glucose as carbon source with L-asparagine as sole nitrogen source and pH of 7.0, an incubation temperature of 28 degrees C showed a two-fold increase, while the incubation period was halved. This work is a primary study on L-asparaginase producing tropical mangrove yeast belonging to genus Cyberlindnera aiming to understand the influence of physical factors and nutrient sources on enzyme production.