title: Gelatin enhances 2-keto-L-gulonic acid production based on Ketogulonigenium vulgare genome annotation.
abstract: In the two-step fermentative production of vitamin C, its precursor 2-keto-L-gulonic acid (2-KLG) was synthesized by Ketogulonicigenium vulgare through co-culture with Bacillus megaterium. The reconstruction of the amino acid metabolic pathway through completed genome sequence annotation demonstrated that K. vulgare was deficient in one or more key enzymes in the de novo biosynthesis pathways of eight different amino acids (L-histidine, L-glycine, L-lysine, L-proline, L-threonine, L-methionine, L-leucine, and L-isoleucine). Among them, L-glycine, L-proline, L-threonine, and L-isoleucine play vital roles in K. vulgare growth and 2-KLG production. The addition of those amino acids increased the 2-KLG productivity by 20.4%, 17.2%, 17.2%, and 11.8%, respectively. Furthermore, food grade gelatin was developed as a substitute for the amino acids to increase the cell concentration, 2-KLG productivity, and L-sorbose consumption rate by 10.2%, 23.4%, and 20.9%, respectively. As a result, the fermentation period decreased to 43 h in a 7-L fermentor.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China. mingll@jiangnan.edu.cn
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
authors.forename: Kejie
authors.initials: K
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001205:Ascorbic Acid / Q000096:biosynthesis*; D001410:Bacillus megaterium / Q000235:genetics* / Q000378:metabolism; D005285:Fermentation; D005780:Gelatin; D016680:Genome, Bacterial; D041902:Rhodobacteraceae / Q000235:genetics* / Q000378:metabolism; D013400:Sugar Acids / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000596:Amino Acids; D013400:Sugar Acids; D005780:Gelatin; C011491:provitamin C; D001205:Ascorbic Acid