title: [Enhancing 2-keto-L-gulonic acid production under hyperosmotic stress by adding sucrose].
abstract: This study aimed to further enhance 2-keto-L-gulonic acid (2-KLG) production efficiency. A strategy for enhancing Ketogulonigenium vulgare growth and 2-KLG production by improving B. megaterium growth with sucrose was developed based on the time course of osmolality during 2-KLG industrial scale fermentation and effects of osmolality on cells growth and 2-KLG production. Results showed that the accumulation of 2-KLG and the feeding of alkaline matter led to an osmolality rise of 832 mOsmol/kg in the culture broth. High osmotic stress (1 250 mOsmol/kg) made the growth ofB. megaterium and K. vulgare decreased 15.4% and 31.7%, respectively, and consequently the titer and productivity of 2-KLG reduced 67.5% and 69.3%, respectively. When supplement sucrose under high osmotic condition (1 250 mOsmol/kg), B. megaterium growth was significantly improved, with the result that 2-KLG production was increased 87%. Furthermore, by applying this sucrose addition strategy further to batch fermentation in 3 L fermentor, the productivity of 2-KLG increased 10.4%, and the duration of fermentation declined 10.8%. The results presented here provide a potential strategy for enhancing the target metabolites produced by mixed strains at environmental stress.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Kejie
authors.initials: K
authors.lastname: Chen
authors.forename: Jingwen
authors.initials: J
authors.lastname: Zhou
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Guocheng
authors.initials: G
authors.lastname: Du
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
mesh_terms: D001410:Bacillus megaterium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D007218:Industrial Microbiology; D009995:Osmosis; D041902:Rhodobacteraceae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013312:Stress, Physiological; D013395:Sucrose / Q000494:pharmacology*; D013400:Sugar Acids / Q000378:metabolism*
chemical_list: D013400:Sugar Acids; D013395:Sucrose; C011491:provitamin C