Soni Pankaj, Prasad Gandhan S, Banerjee Uttam C
Biocatalysis Laboratory, Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar 160 062, India.
Bioprocess Biosyst Eng. 2006 Aug;29(3):149-56. doi: 10.1007/s00449-006-0066-z. Epub 2006 Jun 13.
Culture conditions have been optimized for a newly isolated yeast strain Candida viswanathii PBR2 which is capable of reducing a wide variety of aryl ketones with high stereospecificity. Studies on the culture conditions and catalytic performance of this microorganism showed that the carbonyl reductase occurs constitutively in the cells and its production is enhanced by feeding with acetophenone (2 mM) during the early period of cultivation. Mannitol (1%, wv(-1)) was found to be beneficial both for growth and enzyme production. Supplementation of the media with yeast extract (1.0%, wv(-1)) and Ca(2+ ) (4 mM) enhanced the enzyme production. The optimal temperature and pH for the growth and enzyme production were 25 degrees C and 9.0, respectively. Excellent conversions along with almost absolute enantioselectivity were observed when the resting cells of this yeast strain were exploited to carry out the stereoselective reduction of a number of aryl ketones.
已针对新分离出的酵母菌株维斯瓦纳蒂念珠菌PBR2优化了培养条件，该菌株能够以高立体特异性还原多种芳基酮。对该微生物的培养条件和催化性能的研究表明，羰基还原酶在细胞中组成性存在，并且在培养初期通过加入苯乙酮（2 mM）可提高其产量。发现甘露醇（1%，wv(-1)）对生长和酶的产生均有益。向培养基中添加酵母提取物（1.0%，wv(-1)）和Ca(2+)（4 mM）可提高酶的产量。生长和酶产生的最佳温度和pH分别为25℃和9.0。当利用该酵母菌株的静止细胞对多种芳基酮进行立体选择性还原时，观察到了优异的转化率以及几乎绝对的对映选择性。
