title: Asymmetric synthesis of (R)-1,3-butanediol from 4-hydroxy-2-butanone by a newly isolated strain Candida krusei ZJB-09162.
abstract: Biocatalytic asymmetric preparation of (R)-1,3-butanediol has been attracting much attention in pharmaceuticals industry. A new ideal strain, ZJB-09162, which exhibited high reduction activity and excellent (R)-stereospecificity towards 4-hydroxy-2-butanone, has been successfully isolated from soil samples. Based on morphology, physiological tests (API 20 C AUX), and 5.8S-ITS sequence, the isolate was identified as Candida krusei. Kinetic characterization demonstrated that carbonyl reductase from C. krusei ZJB-09162 preferred NADH to NADPH as cofactor, indicating it might be a new carbonyl reductase. (R)-1,3-Butanediol was produced in 19.8 g/L, 96.6% conversion, and 99.0% ee at optimal pH 8.5, 35 °C with a 2:1 molar ratio of glucose to 4H2B. In order to achieve higher product titer, the substrate loading was optimized in fixed catalysts and fixed substrate/catalysts ratio mode. The bioreduction of 4-hydroxy-2-butanone at a concentration of 45.0 g/L gave (R)-1,3-butanediol in 38.7 g/L and 83.9% conversion. Therefore, C. krusei ZJB-09162 was, for the first time, proven to be a promising biocatalyst for enzymatic preparation of (R)-1,3-butanediol.
authors.affiliation: Institute of Bioengineering, Zhejiang University of Technology, Hangzhou, People's Republic of China.
authors.forename: Ren-Chao
authors.initials: RC
authors.lastname: Zheng
authors.forename: Zheng
authors.initials: Z
authors.lastname: Ge
authors.forename: Zhao-Kuan
authors.initials: ZK
authors.lastname: Qiu
authors.forename: Yuan-Shan
authors.initials: YS
authors.lastname: Wang
authors.forename: Yu-Guo
authors.initials: YG
authors.lastname: Zheng
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D002074:Butanones / Q000378:metabolism*; D002072:Butylene Glycols / Q000378:metabolism*; D002175:Candida / Q000302:isolation & purification* / Q000378:metabolism*; D016000:Cluster Analysis; D003067:Coenzymes / Q000378:metabolism; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D016533:Mycological Typing Techniques; D009243:NAD / Q000378:metabolism; D010802:Phylogeny; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013237:Stereoisomerism
chemical_list: D002074:Butanones; D002072:Butylene Glycols; D003067:Coenzymes; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012340:RNA, Ribosomal, 5.8S; D009243:NAD; C028491:1,3-butylene glycol; C005222:methylethyl ketone; D000429:Alcohol Oxidoreductases