title: Gluconic acid production by gad mutant of Klebsiella pneumoniae.
abstract: Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g.
authors.affiliation: Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, People's Republic of China.|Department of Biological Engineering, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, People's Republic of China.|Biorefinery Research Center, Jeonbuk Branch Institute, KRIBB, Jeongeup, Jeonbuk, 580-185, South Korea.
authors.forename: Dexin
authors.initials: D
authors.lastname: Wang
authors.affiliation: Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, People's Republic of China.|Department of Biological Engineering, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, People's Republic of China.
authors.forename: Chenhong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wei
authors.affiliation: Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, People's Republic of China.|School of Life Science and Technology, ShanghaiTech University, Shanghai, People's Republic of China.
authors.forename: Jiping
authors.initials: J
authors.lastname: Shi
authors.affiliation: Biorefinery Research Center, Jeonbuk Branch Institute, KRIBB, Jeongeup, Jeonbuk, 580-185, South Korea.
authors.forename: Chul Ho
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, People's Republic of China.
authors.forename: Biao
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Biological Engineering, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, People's Republic of China. hanzs@ysu.edu.cn.
authors.forename: Zengsheng
authors.initials: Z
authors.lastname: Han
authors.affiliation: Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, People's Republic of China. haoj@sari.ac.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Hao
mesh_terms: D001426:Bacterial Proteins; D061249:Batch Cell Culture Techniques / Q000379:methods*; D002237:Carbohydrate Dehydrogenases / Q000172:deficiency*; D003470:Culture Media / Q000032:analysis; D005285:Fermentation; D017353:Gene Deletion; D005942:Gluconates / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D060847:Metabolic Engineering; D009876:Operon
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D005942:Gluconates; D002237:Carbohydrate Dehydrogenases; D005947:Glucose; C030691:gluconic acid
keywords: Gluconate dehydrogenase; Gluconic acid; Glucose oxidation pathway; Klebsiella pneumoniae