Study of hydrolytic enzymes activity and stability of the isolated yeast close to Zygoascus hellenicus

Lipase is one of the most well-known and essential biocatalysts in the detergent, food, and pharmaceutical industries. Microbial lipase sources such as yeasts are applicable due to their stability in harsh conditions. In this study, the effect of temperature, initial pH, and incubation time were investigated to improve the extracellular lipase production by yeast, named Zygoascus hellenicus strain MZ_574439 T. Strain MZ_574439 T has already been isolated and registered from Iran. In the current project, strain MZ_574439 T with 99% similarity to Z. hellenicus was isolated from water samples. Our findings showed that the isolated strain has a remarkable difference from its close phylogenetic species in the production of lipase and can produce extracellular lipase up to 7.2 U/ml while the Z. hellenicus has no ability of lipase production. The isolated strain was not able to produce other hydrolytic enzymes. The enzyme activity results showed that the best activity for the isolated lipase is pH= 7 and 37 °C. The best stability condition for the enzyme occurs at 50 °C and pH =7. From the current study, it can be concluded that Z. hellenicus produces lipase. The lipase enzyme production was optimized with different physiological conditions. Yeast extract could be a better source for maximum lipase production.