摘要
考察了β-环糊精(β-cyclodextrin,CD)对雄甾-4-烯-3,17-二酮(androst-4-ene-3,17-dione,AD)在水中的溶解度及微生物对其11α羟化反应的影响,结果表明β-环糊精能显著提高底物AD在发酵培养基中的溶解度,增溶效果优于有机溶剂。在底物投料浓度0.2%(w/v)时,与4%无水乙醇投料方式相比,8g/L CD能使AD转化率提高约10%,达到73.2%,并且使转化时间缩短至60h左右。在CD与AD的最佳摩尔比1:1的条件下,能使投料浓度提高至0.3%(w/v)。本研究采用ROESY对CD-AD包合物结构进行鉴定,结果表明甾体母核深入到环糊精笼形分子空腔内部,形成稳定的包合物。
The effects of β-cyclodextrin on water-solubility of steroid substrate androst-4-ene-3, 17-dione （AD） and hydroxylation by Metarhizium anisopliae M28-203 were investigated. The results indicated that β-cyclodextrin could improve the solubility of androst-4-ene-3, 17-dione in fermentation medium efficiently. Compared with 4% ethanol, 8 g/L 13-cyclodextrin could increase the conversion rate by 10% when the substrate concentration was 0.2% （w/v）. Furthermore, the transformation time was shortened to 60 h. These suggested that the solubilization of β-cyclodextrin could facilitate the transportation of substrate inside the cell and then improve steroid bioconversion efficiency. Moreover β-cyclodextrin could improve substrate concentration to 0.3 % （w/v） with the optimal molar ratio of β-cyclodextrin： AD of 1：1. Rotating frame overhauser effect spectroscopy （ROESY） was applied in structure determination of β-cyclodextrin： AD inclusion complex. The data indicated that the steroid skeletal was immersed in the β-cyclodextrin cavity and stable inclusion complex was formed.
出处
《工业微生物》
CAS
CSCD
2011年第1期1-4,共4页
Industrial Microbiology
基金
国家自然科学基金(No.30772676)资助
