Identification Of Lipase – Producing Psychrophilic Yeast, Leucosporidium Sp.

Abstract

Cold-active enzymes have recently received great attention due to their potential applications in a broad range of industrial, agricultural and medical processes. One of the enzymes is lipase (triacyglycerol acylhydrolases E.C 3.1.1.3) which is unique in catalyzing the hydrolysis of triacylglycerols into free fatty acids and glycerol. In this particular research, an obligate psychrophilic microorganism was isolated from Casey Station, Antarctica. The growth of this microorganism has been tested at different temperatures, 4C, 27C and 37C. At 4C, the microorganism was able to grow whereas at 27C and 37C, there was no growth at all. The presence of lipase enzyme in this microorganism was detected by halo zone on palm oil (substrate) agar plates. Identification of this microorganism was done based on its morphological, biochemical and molecular characteristics. For the morphology analysis, two types of microscopy observation were carried out: phase contrast microscopy and Scanning Electron Microscopy (SEM). Both observations showed budding structures. This suggested that this particular microorganism is psychrophilic yeast. Biochemical tests were done based on its capability to ferment and assimilate sugar. In addition, assimilation of nitrate was also tested. In molecular approach, the genomic DNA (gDNA) of this microorganism was successfully extracted and the extracted gDNA was used for amplification via polymerase chain reaction (PCR) technique using Internal Transcribed Spacer (ITS) primers. The PCR product obtained was sequenced and submitted for Basic Local Alignment Search Tool (BLAST) at National Center for Biotechnological Information (NCBI). The analysis showed that this microorganism contained ITS sequences (highest identity with Leocosporidium sp.).