Study of Hydrolytic Enzymes Activity and Stability of the Isolated Yeast Close to Zygoascus hellenicus

Background: Lipase is one of the most well-known and essential biocatalysts in the de-tergent, food, and pharmaceutical industries. Microbial lipase sources such as yeasts are applicable due to their stability in harsh conditions. Objective: 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. Methods: 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. Results: Our findings showed that the isolated strain has a remarkable difference from its close phy-logenetic 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 pro-duce other hydrolytic enzymes. The enzyme activity results showed that the best activity for the iso-lated lipase is pH= 7 and 37°C. The best stability condition for the enzyme occurs at 50°C and pH =7. Conclusion: From the current study, it can be concluded that Z. hellenicus produces lipase. The li-pase enzyme production was optimized with different physiological conditions. Yeast extract could be a better source for maximum lipase production.