Selection of lipases-producing yeasts from mangrove and marine environments

Abstract

In order to isolate highly efficient lipase producing yeast, the present study aimed to investigate lipase production by using various carbon source as the substrates. Seventy-three yeast strains were isolated from mangrove forests, sea water and sea sediments by enrichment technique. These strains were screened for lipase production on agar medium containing tributyrin and Tween 80 by plate assay method. A clear zone on tributyrin solid medium was observed from 60 yeast strains, and 10 strains showed opaque zone on Tween 80 solid medium. The enzyme activity index (EAI) of strain SPA4-2 was sharply high value on tributyrin medium (EAI=3.38) whereas BP12 strain was effective highly value on Tween 80 medium (EAI=2.16). The lipase activity of the yeast strains SPA4-2 and BP12 were also estimated in media containing various carbon sources such as 20 g/L each of tributyrin, Tween 80, commercial palm oil and waste cooking oil. The results implied that extracellular lipase activity of SPA4-2 and BP12 after incubation at 120 h in medium supplemented with commercial palm oil were 1.53±0.11 and 0.75±0.06 units/mL, respectively. The yeast strain SPA4-2 that produced high lipase activity was identified as Cryptococcus liquefaciens with 99.83% sequence similarity to C. liquefaciens CBS 968^T (AF181515).  These results indicated the strain SPA4-2 was suitable for lipase production and will be utilized in the industries in the future.