초록
<P><B>Abstract</B></P><P><B>BACKGROUND:</B> As a new protein expression and self‐immobilization system, cell‐surface displayed enzymes have attracted increasing attention. In this study, <I>Geotrichum</I> sp. lipase (GSL), an important enzyme for the enrichment of polyunsaturated fatty acids (PUFAs), was first displayed on the cell surface of <I>Saccharomyces cerevisiae</I>.</P><P><B>RESULTS:</B> The activity of displayed GSL was higher (43.7 U g<SUP>−1</SUP> dry cell) than that of <I>Candida antarctica</I> lipase B (26.26 U g<SUP>−1</SUP> dry cell) and that of <I>Rhizopus oryzae</I> lipase (4.1 U g<SUP>−1</SUP> dry cell). It also exhibited higher thermostability than the free lipase, and retained 89% of the original activity after incubation at 40 °C for 3 h, compared with 48% at 35 °C for the free lipase at pH 8.5. Interestingly, the displayed lipase had a wider pH range and better pH stability. It had higher activity at all pH values than the free GSL, and retained 86% of the original activity in the pH range 9.5 to 10.5, whereas the activity of the free GSL could not be detected at pH 10.</P><P><B>CONCLUSION:</B> This work presented a method to prepare a whole‐cell biocatalyst with better stability and broader pH tolerance which will provide a useful strategy for other cost‐effective self‐immobilized industrial lipases. Copyright © 2011 Society of Chemical Industry</P>