Cell surface display of Staphylococcus haemolyticus L62 lipase in Escherichia coli and its application as a whole cell biocatalyst for biodiesel production

Staphylococcus haemolyticus L62 (SHL62) lipase was displayed on the cell surface of Escherichia coli using an autotransporter protein of Pseudomonas putida EstA beta 8 as an anchoring motif. Localization of the SHL62 lipase on the cell surface of E. coli was confirmed by immunofluorescence microscopy, flow cytometry analysis, Western blot, protease accessibility, and whole-cell enzyme activity assays. SHL62 lipase activity of whole cells reached 168 U/g dry cell weight toward p-nitrophenyl caprylate after being induced by 0.1 mM IPTG for 24 h. The optimum temperature and pH of the displayed SHL62 lipase was 40-45 degrees C and pH 10, respectively. The displayed SHL62 was stable up to 45 C, at which it had >80% of maximum activity. The displayed SHL62 lipase showed a preference for medium chain fatty acids of p-nitrophenyl esters. Moreover, the displayed SHL62 lipase was used as a whole cell catalyst to produce biodiesel that was obtained at a yield of nearly 89.4% after a 96 h reaction at 30 degrees C. These results suggest that the displayed SHL62 lipase on the cell surface of E. coli using an EstA beta 8 anchoring motif can be used for biocatalytic applications. (C) 2013 Elsevier B.V. All rights reserved.