title: Production of ectoine through a combined process that uses both growing and resting cells of Halomonas salina DSM 5928T.
abstract: Using ectoine-excreting strain Halomonas salina DSM 5928(T), we developed a new process for high-efficiency production of ectoine, which involved a combined process of batch fermentation by growing cells and production by resting cells. In the first stage, batch fermentation was carried out using growing cells under optimal fermentation conditions. The second stage was the production phase, in which ectoine was synthesized and excreted by phosphate-limited resting cells. Optimal conditions for synthesis and excretion of ectoine during batch fermentation in a 10 l fermentor were 0.5 mol l(-1) NaCl and an initial monosodium glutamate concentration of 80 g l(-1) respectively. The pH was adjusted to 7.0 and the temperature was maintained at 33°C. In phosphate-limited resting cells medium, monosodium glutamate and NaCl concentration was 200 g l(-1) and 0.5 mol l(-1), respectively, as well as pH was 7.0. The total concentration of ectoine produced was 14.86 g l(-1), the productivity and yield of ectoine was 7.75 g l(-1) day(-1) and 0.14 g g(-1), respectively, and the percentage of ectoine excreted was 79%. These levels of ectoine production and excretion are the highest reported to date.
authors.affiliation: Environmental Science and Engineering College, Dalian Maritime University, 1 Linghai Road, 116026 Dalian, People's Republic of China.
authors.forename: Ya-jun
authors.initials: YJ
authors.lastname: Lang
authors.forename: Lin
authors.initials: L
authors.lastname: Bai
authors.forename: Ya-nan
authors.initials: YN
authors.lastname: Ren
authors.forename: Ling-hua
authors.initials: LH
authors.lastname: Zhang
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nagata
mesh_terms: D000599:Amino Acids, Diamino / Q000096:biosynthesis* / Q000737:chemistry; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003470:Culture Media; D000431:Ethanol / Q000737:chemistry; D005285:Fermentation; D018698:Glutamic Acid / Q000737:chemistry; D020632:Halomonas / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
chemical_list: D000599:Amino Acids, Diamino; D003470:Culture Media; D000431:Ethanol; D018698:Glutamic Acid; D012965:Sodium Chloride; C045628:ectoine