Enhanced production of L-sorbose by systematic engineering of dehydrogenases in Gluconobacter oxydans  

作　　者：Li Liu Yue Chen Shiqin Yu Jian Chen Jingwen Zhou 

机构地区：[1]National Engineering Laboratory for Cereal Fermentation Technology,Jiangnan University,1800 Lihu Road,Wuxi,Jiangsu,214122,China [2]School of Biotechnology and Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,1800 Lihu Road,Wuxi,Jiangsu,214122,China [3]Science Center for Future Foods,Jiangnan University,1800 Lihu Road,Wuxi,Jiangsu,214122,China [4]Jiangsu Provisional Research Center for Bioactive Product Processing Technology,Jiangnan University,1800 Lihu Road,Wuxi,Jiangsu,214122,China

出　　处：《Synthetic and Systems Biotechnology》2022年第2期730-737,共8页合成和系统生物技术（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(Key Program,31830068).

摘　　要：L-Sorbose is an essential intermediate for the industrial production of vitamin C(L-ascorbic acid).However,the formation of fructose and some unknown by-products significantly reduces the conversion ratio of D-sorbitol to L-sorbose.This study aimed to identify the key D-sorbitol dehydrogenases in Gluconobacter oxydans WSH-003 by gene knockout.Then,a total of 38 dehydrogenases were knocked out in G.oxydans WSH-003,and 23 dehydrogenase-deficient strains could increase L-sorbose production.G.oxydans-30,wherein a pyrroloquinoline quinone-dependent glucose dehydrogenase was deleted,showed a significant reduction of a by-product with the extension of fermentation time.In addition,the highest conversion ratio of 99.60%was achieved in G.oxydans MD-16,in which 16 different types of dehydrogenases were inactivated consecutively.Finally,the gene vhb encoding hemoglobin was introduced into the strain.The titer of L-sorbose was 298.61 g/L in a 5-L bioreactor.The results showed that the systematic engineering of dehydrogenase could significantly enhance the production of L-sorbose.

关 键 词：D-sorbitol dehydrogenase Gluconobacter oxydans L-ascorbic acid Metabolic engineering 

分 类 号：Q93[生物学—微生物学]