초록
<P><B>Highlights</B></P><P>► CALB-displaying <I>P. pastoris</I> exhibited high synthetic activity as a whole-cell biocatalysts. ► It showed good tolerance for temperature and high substrate concentrations. ► 12 kinds of flavor esters were synthesized very efficiently in a 5-l batch reactor. ► This biocatalyst is promising for potential use for the commercial production.</P> <P><B>Abstract</B></P><P><I>Candida antarctica</I> lipase B (CALB) has been employed as an efficient catalyst in the preparation of many flavor esters. A CALB-displaying yeast whole-cell biocatalyst could be an attractive alternative to commercial immobilized CALB because of its low-cost preparation and high enzymatic activity. We investigated the potential application of CALB-displaying <I>Pichia pastoris</I> cells for the production of flavor esters. The optimal conditions for flavor esters synthesis by this biocatalyst were determined in 50-ml shake flasks. Under optimized conditions, the synthesis of 12 kinds flavor esters were scaled up in a 5-l batch stirred reactor. Among these, the mole conversions of 10 exceeded 95% after reactions for 4h. In addition, this biocatalyst showed good tolerance for high substrates concentration and excellent operational stability. Repeated use of the cells in 10 batches resulted in an activity loss of less than 10%. Thus, CALB-displaying <I>P. pastoris</I> whole cells are robust biocatalysts with potential commercial application in the large-scale production of flavor esters in non-aqueous media.</P>