Molecular characterization of Yarrowia lipolytica strains isolated from different environments and lipase profiling

Authors: ONUR AKPINAR, FÜSUN BAHRİYE UÇAR

Abstract: In order to analyze yeasts that produce industrial compounds, it is essential to identify them accurately. Yarrowia lipolytica is one of the most extensively studied 'nonconventional' yeasts, being a strictly aerobic microorganism capable of producing important metabolites and having an intense secretory activity, which justifies efforts to use it in industry (as a biocatalyst), in molecular biology, and in studies of genetics. Therefore, in this study, an accurate identification of Y. lipolytica strains was performed using 3 different molecular biological methods (RFLP analysis of ITS1-5.8S rDNA-ITS2 and 18S rDNA regions and sequencing of the D1/D2 domain of the 26S rDNA region). The 26S rRNA gene sequence of the strains showed sequence homology with various Y. lipolytica strains from the National Center for Biotechnology Information. A number of different lipids (tributyrin, olive oil, and fish oil) were screened in terms of the growth of Y. lipolytica strains and lipase production. It was determined that all lipid-related substrates supported lipase production levels ranging from 4.27 U/mL (tributyrin) to 37.08 U/mL (fish oil). Fish oil (1%) showed maximum specific activity in the supernatant (264.85 U/mg of protein) and TEM TAN 46. The Y. lipolytica strain that was produced in the media containing fish oil was found to be the best lipase producer.

Keywords: Yarrowia lipolytica, molecular characterization, PCR-RFLP of rDNA, sequencing of D1/D2 domain, extracellular lipase

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