Efficient Bioconversion Of Daptomycin To Its Nucleus By Heterologous Expression Of Deacylase Genes In Streptomyces

BACKGROUND Daptomycin is an effective clinical drug for treating Staphylococcus aureus bacteraemia. Daptomycin and its derivatives are essential resources for antimicrobial screening and drug development. The daptomycin nucleus is a critical intermediate for producing daptomycin and its derivatives; it is catalysed by deacylase from Actinoplanes utahensis. However, the yield of the daptomycin nucleus was low by the original strain. RESULTS In this study, the deacylase gene was overexpressed in the heterologous hosts of three different Streptomyces strains, and the efficiency of recombinant Streptomyces coelicolor was higher than that of the other two strains. Daptomycin and its nucleus were isolated, their structures were identified by nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS), and its bioconversion was confirmed by high-performance liquid chromatography (HPLC). The optimal conditions were a phosphate buffer with 0.2 mol L-1 KCl, pH 7.0, and temperature of 40 degrees C, with a reaction time >4 h; in these conditions, the bioconversion efficiency increased from 71.04% to 85.02%, which is an increase of 16.44%. In addition, daptomycin nucleus yield could reach 4.36 g L-1 when 8 g L-1 daptomycin was added to the 200 mL reaction system by recombinant S. coelicolor, and the yield was 1.23 g L-1 when 6 g L-1 of daptomycin was introduced into wild-type strain in a preliminary study for further industrialization applications. CONCLUSION These results are helpful for enhancing daptomycin nucleus production in recombinant Streptomyces. Our work could make it possible to commercialise the daptomycin nucleus-overproducing stains and provide a library of chemical substances for antibacterial screening and drug development. (c) 2021 Society of Chemical Industry (SCI).