title: Glutathione enhances 2-keto-l-gulonic acid production based on Ketogulonicigenium vulgare model iWZ663.
abstract: Ketogulonicigenium vulgare is used widely during the industrial production of 2-keto-l-gulonic acid (2-KLG), the precursor of vitamin C, in a coculture with Bacillus megaterium. We analyzed the sulfate and coenzyme A metabolic module in the genome-scale metabolic model (GSMM) iWZ663 and found that the poor growth of K. vulgare was due to a deficiency in key reductases in the sulfate metabolic pathway. To carefully investigate the metabolism of sulfate, we developed a chemically defined medium (CDM) to produce pure cultures of K. vulgare. The addition of glutathione and l-cysteine to a flask culture of K. vulgare increased the cell growth, 2-KLG titer, and the intracellular coenzyme A level by 38.7%, 45.5%, and 85.3%, respectively, with glutathione, and by 25.6%, 35.8%, and 44.7%, respectively, with l-cysteine. The addition of glutathione to a 7-L fermenter culture of K. vulgare and B. megaterium increased the 2-KLG productivity by 20.9%. This study shows that the analysis of a specific metabolic module in GSMM can provide a potential strategy for optimizing microbial physiological functions.
authors: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
authors: Zheng
authors: Z
authors: Huang
authors: Wei
authors: W
authors: Zou
authors: Jie
authors: J
authors: Liu
authors: Liming
authors: L
authors: Liu
mesh_terms: D001709:Biotechnology / Q000379:methods; D049109:Cell Proliferation; D005285:Fermentation; D005978:Glutathione / Q000494:pharmacology*; D007218:Industrial Microbiology; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D010205:Pantothenic Acid; D041902:Rhodobacteraceae / Q000187:drug effects* / Q000378:metabolism*; D013400:Sugar Acids / Q000032:analysis / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism
chemical_list: D013400:Sugar Acids; D013431:Sulfates; D010205:Pantothenic Acid; D005978:Glutathione; C011491:provitamin C