title: Two-helper-strain co-culture system: a novel method for enhancement of 2-keto-L-gulonic acid production.
abstract: A novel two-helper-strain co-culture system (TSCS) was developed to enhance 2-keto-L-gulonic acid (2-KLG) productivity for vitamin C production. Bacillus megaterium and B. cereus (with a seeding culture ratio of 1:3, v/v), used as helper strains, increased the 2-KLG yield using Ketogulonigenium vulgare compared to the conventional one-helper-strain (either B. cereus or B. megaterium) co-culture system (OSCS). After 45 h cultivation, 2-KLG concentration in the TSCS (69 g l(-1)) increased by 8.9 and 7 % over that of the OSCS (B. cereus: 63.4 g l(-1); B. megaterium: 64.5 g l(-1)). The fermentation period of TSCS was 4 h shorter than that of OSCS (B. cereus). The increased cell numbers of K. vulgare stimulated by the two helper strains possibly explain the enhanced 2-KLG yield. The results imply that TSCS is a viable method for enhancing industrial production of 2-KLG.
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, China, mandlaa@foxmail.com.
authors.lastname: Mandlaa
authors.forename: Weichao
authors.initials: W
authors.lastname: Yang
authors.forename: Litao
authors.initials: L
authors.lastname: Han
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
mesh_terms: D001409:Bacillus cereus / Q000254:growth & development*; D001410:Bacillus megaterium / Q000254:growth & development*; D005285:Fermentation; D041902:Rhodobacteraceae / Q000254:growth & development* / Q000378:metabolism*; D013400:Sugar Acids / Q000378:metabolism*; D013997:Time Factors
chemical_list: D013400:Sugar Acids; C011491:provitamin C