Analysis of D-Sorbitol Dehydrogenase Gene in Gluconobacter oxydans WSH-003

Abstract:

Gluconobacter oxydans WSH-003 is an L-sorbose production strain，mainly used of industrial production of Vitamin C. It can effectively oxidize D-sorbitol into L-sorbose with a high yield. The whole genome sequence of G. oxydans WSH-003 reveals that there are three different gene clusters for D-sorbitol dehydrogenase，whereas the gene expression of these three gene clusters in this strain has not been studied. In this study，two D-sorbitol dehydrogenases were proved to be PQQ dependent D-sorbitol dehydrogenase（PQQ-SLDH） and one was FAD dependent D-sorbitol dehydrogenase（FAD-SLDH） by using the BLAST software in NCBI. The transcription analysis of strain cells from 4 h，8 h，12 h，20 h and 40 h in fermentation cultivation were further studied using the high through-out RNA-Seq technology. The result showed that sldhAB2 on gene locus O1G_RS0104395/O1G_RS0104400 had a very low transcript level （FPKM，Fragments Per Kilobase of exon model per Million mapped reads） in all 5 time points，compared with the high FPKM of sldhAB1 on gene locus O1G_RS0105425/O1G_RS0105430 and sldSLC on gene locus O1G_RS0106820/O1G_RS0106825 /O1G_RS0106830. Here，we illustrated that the gene cluster sldSLC and sldAB1 played an important role in the oxidization of D-sorbitol to L-sorbose，which may contribute to the further study of D-sorbitol dehydrogenase genes in the strain.