An lglucitol oxidizing dehydrogenase from Bradyrhizobium japonicumUSDA 110 for production of dsorbose with enzymatic or electrochemical cofactor regeneration

作者：Gauer Sabrina; Wang Zhijie; Otten Harm; Etienne Mathieu; Bjerrum Morten Jannik; Lo Leggio Leila; Walcarius Alain; Giffhorn Friedrich; Kohring Gert Wieland^*

来源：Applied Microbiology and Biotechnology, 2014, 98(7): 3023-3032.

DOI：10.1007/s00253-013-5180-7

• Dehydrogenase
• Cofactor regeneration
• Electrochemistry
• L-glucitol
• D-sorbose

A gene in Bradyrhizobium japonicum USDA 110, annotated as a ribitol dehydrogenase (RDH), had 87 % sequence identity (97 % positives) to the N-terminal 31 amino acids of an l-glucitol dehydrogenase from Stenotrophomonas maltophilia DSMZ 14322. The 729-bp long RDH gene coded for a protein consisting of 242 amino acids with a molecular mass of 26.1 kDa. The heterologously expressed protein not only exhibited the main enantio selective activity with d-glucitol oxidation to d-fructose but also converted l-glucitol to d-sorbose with enzymatic cofactor regeneration and a yield of 90 %. The temperature stability and the apparent K (m) value for l-glucitol oxidation let the enzyme appear as a promising subject for further improvement by enzyme evolution. We propose to rename the enzyme from the annotated RDH gene (locus tag bll6662) from B. japonicum USDA as a d-sorbitol dehydrogenase (EC 1.1.1.14).

• 出版日期2014-4