Co-expression, purification and characterization of the lipase and foldase of Burkholderia contaminans LTEB11

Abstract Genes encoding lipase LipBC ( lipA ) and foldase LifBC ( lipB ) were identified in the genome of Burkholderia contaminans LTEB11. Analysis of the predicted amino acid sequence of lipA showed its high identity with lipases from Pseudomonas luteola (91%), Burkholderia cepacia (96%) and Burkholderia lata (97%), and classified LipBC lipase in the lipase subfamily I.2. The genes lipA and lipB were amplified and cloned into expression vectors pET28a(+) and pT7-7, respectively. His-tagged LipBC and native LifBC were co-expressed in Escherichia coli and purified. LipBC and LifBC have molecular weights of 35.9 kDa and 37 kDa, respectively, and remain complexed after purification. The Lip-LifBC complex was active and stable over a wide range of pH values (6.5–10) and temperatures (25–45 °C), with the highest specific activity (1426 U mg −1 ) being against tributyrin. The Lip-LifBC complex immobilized on Sepabeads was able to catalyze the synthesis of ethyl-oleate in n ‑hexane with an activity of 4 U g −1 , maintaining high conversion (>80%) over 5 reaction cycles of 6 h at 45 °C. The results obtained in this work provide a basis for the development of applications of recombinant LipBC in biocatalysis.