Dynamic Co-Cultivation Process of Corynebacterium glutamicum Strains for the Fermentative Production of Riboflavin

Fermentation

DinaR. Kallman¹  Nadav Bar¹  Fernando Pérez-García¹  VolkerF. Wendisch²  Arthur Burgardt² 

[1]Department of Chemical Engineering Faculty of Natural Sciences, Norges Teknisk-Naturvitenskapelige Universitet (NTNU), NO-7491 Trondheim, Norway

[2]Genetics of Prokaryotes, Faculty of Biology & Center for Biotechnology (CeBiTec), Bielefeld University, 33617 Bielefeld, Germany

关键词: Corynebacterium glutamcium;    riboflavin;    mannose;    xylose;    bioreactor;    co-cultivation;   

DOI  :  10.3390/fermentation7010011

来源: DOAJ

【 摘 要 】

Residual streams from lignocellulosic processes contain sugar mixtures of glucose, xylose, and mannose. Here, the industrial workhorse Corynebacterium glutamicum was explored as a research platform for the rational utilization of a multiple sugar substrate. The endogenous manA gene was overexpressed to enhance mannose utilization. The overexpression of the xylA gene from Xanthomonas campestris in combination with the endogenous xylB gene enabled xylose consumption by C. glutamicum. Furthermore, riboflavin production was triggered by overexpressing the sigH gene from C. glutamicum. The resulting strains were studied during batch fermentations in flasks and 2 L lab-scale bioreactors separately using glucose, mannose, xylose, and a mixture of these three sugars as a carbon source. The production of riboflavin and consumption of sugars were improved during fed-batch fermentation thanks to a dynamic inoculation strategy of manA overexpressing strain and xylAB overexpressing strain. The final riboflavin titer, yield, and volumetric productivity from the sugar mixture were 27 mg L⁻¹, 0.52 mg g⁻¹, and 0.25 mg L⁻¹ h⁻¹, respectively. It reached a 56% higher volumetric productivity with 45% less by-product formation compared with an equivalent process inoculated with a single strain overexpressing the genes xylAB and manA combined. The results indicate the advantages of dynamic multi strains processes for the conversion of sugar mixtures.

【 授权许可】

Unknown