Transesterification of plant oils using Staphylococcus haemolyticus L62 lipase displayed on Escherichia coli cell surface using the OmpA signal peptide and EstAβ8 anchoring motif
•Staphylococcus haemolyticus L62 lipase was displayed on E. coli cell surface.•L62 lipase was fused with E. coli OmpA signal peptide and Pseudomonas putida EstAβ8.•Displayed L62 lipase showed high lipase activity toward various triglycerides.•L62 lipase performed transesterification reactions using various oils and alcohols.
Staphylococcus haemolyticus L62 (SHL62) lipase was displayed on the outer membrane of Escherichia coli using the OmpA signal peptide and the autotransporter EstAβ8 protein. Localization of SHL62 lipase on the outer membrane of E. coli was confirmed using immunofluorescence microscopy and flow cytometry analysis. Lipase activity of the displayed SHL62 lipase was also measured using spectrophotometry and pH titration. SHL62 lipase activity of whole cells reached 2.0 U/ml culture (OD600 nm of 10) when it was measured by the p-nitrophenyl caprylate assay after being induced with 1 mM IPTG for 24 h. The optimum temperature and pH for the lipase was 45 °C and 10, respectively. Furthermore, it maintained more than 90% of maximum lipase activity at up to 50 °C and in a pH range of 5–9. The hydrolytic activity assay conduted with various substrates confirmed that p-nitrophenyl caprylate and corn oil were preferred substrates among various synthetic and natural substrates, respectively. The displayed SHL62 lipase produced fatty acid esters from various alcohols and plant oils through transesterification.
Journal: Enzyme and Microbial Technology - Volume 67, December 2014, Pages 32–39