title: [Production of L(+)-tartaric acid by immobilized Rhizobium strain BK-20].
abstract: The cis-epoxysuccinate hydrolase (CESH) from Rhizobium strain BK-20 is the key enzyme for L(+)-tartaric acid production. To establish a highly efficient and stable production process, we first optimized the enzyme production from Rhizobium strain BK-20, and then developed an immobilized cell-culture process for sustained production of L(+)-tartaric acid. The enzyme activity of free cells reached (3 498.0 +/- 142.6) U/g, and increased by 643% after optimization. The enzyme activity of immobilized cells reached (2 817.2 +/- 226.7) U/g, under the optimal condition with sodium alginate as carrier, cell concentration at 10% (W/V) and gel concentration at 1.5% (W/V). The immobilized cells preserved high enzyme activity and normal structure after 10 repeated batches. The conversion rate of the substrate was more than 98%, indicating its excellent production stability.
authors.forename: Xiang
authors.initials: X
authors.lastname: Lan
authors.forename: Wenna
authors.initials: W
authors.lastname: Bao
authors.forename: Haifeng
authors.initials: H
authors.lastname: Pan
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Xie
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000464:Alginates / Q000737:chemistry; D018914:Cells, Immobilized; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006867:Hydrolases / Q000378:metabolism*; D012231:Rhizobium / Q000201:enzymology / Q000378:metabolism*; D013644:Tartrates / Q000378:metabolism*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D013644:Tartrates; D020723:Glucuronic Acid; D006867:Hydrolases; C029768:tartaric acid