Comparison of RfbC gene expression in different chassis cells of Marine bacteria P. a. HAao2018

Abstract

Marine bacteria are one of the most abundant and diverse microbial populations in Marine ecosystems. It is well known that the Marine environment is very complex, which also makes Marine microorganisms have some unique functions to cope with the complex environment, such as the ability to produce exopolysaccharides. The Marine bacterium Pseudoalteromonas agarivorans Hao 2018 was obtained from the body surface biofilm isolation of abalone. It was found that the antioxidant activity of exopolens produced by this bacterium would change regularly under the disturbance of environmental factors, and the composition and proportion of monosaccharides in exopolens and the structure of polysaccharides were significantly changed. Based on transcriptomic analysis, the synthesis module of the rhamnoose precursor in P.a.Hao 2018 exopolysaccharide was successfully identified. In this study, the second key enzyme gene RfbC (DTDP-4-dehydrorhamnoose 3,5 differential isomerase) in the synthesis module of the rhamnoose precursor was cloned and heterologous expressed. Escherichia coli BL21 and Bacillus subtilis 168 were selected as expression hosts, and pHT43 was used as plasmid vector to construct recombinant expression vector. After induced expression, the enzyme protein was purified. The expression of RfbC in different hosts was detected by BCA protein concentration assay kit. The implementation of this study laid a foundation for the exploration of the synthetic pathway of Marine bacteria rhamnose, and provided a theoretical basis for the wide application of P.a.Hao 2018 rhamnose.