Central Laboratories for Key Technologies, KIRIN Company Ltd., 1-13-5 Fukuura Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan.
Appl Microbiol Biotechnol. 2013 Jul;97(14):6231-9. doi: 10.1007/s00253-013-4964-0. Epub 2013 May 15.
A genetically-engineered strain of the yeast Candida utilis harboring genes encoding (1) an acetoacetyl-CoA transferase from Clostridium acetobutylicum ATCC 824, (2) an acetoacetate decarboxylase, and (3) a primary-secondary alcohol dehydrogenase derived from Clostridium beijerinckii NRRL B593 produced up to 0.21 g/L of isopropanol. Because the engineered strain accumulated acetate, isopropanol titer was improved to 1.2 g/L under neutralized fermentation conditions. Optimization of isopropanol production was attempted by the overexpression and disruption of several endogenous genes. Simultaneous overexpression of two genes encoding acetyl-CoA synthetase and acetyl-CoA acetyltransferase increased isopropanol titer to 9.5 g/L. Moreover, in fed-batch cultivation, the resultant recombinant strain produced 27.2 g/L of isopropanol from glucose with a yield of 41.5 % (mol/mol). This is the first demonstration of the production of isopropanol by genetically engineered yeast.
一株经基因工程改造的产朊假丝酵母（Candida utilis）菌株，其携带的基因编码物包括：（1）来自丙酮丁醇梭菌（Clostridium acetobutylicum ATCC 824）的乙酰乙酰辅酶 A 转移酶，（2）乙酰乙酸脱羧酶，以及（3）源自拜氏梭菌（Clostridium beijerinckii NRRL B593）的主辅醇脱氢酶。该工程菌株可生产高达 0.21 g/L 的异丙醇。由于该工程菌株积累了乙酸，因此在中性发酵条件下，异丙醇的产量提高到 1.2 g/L。通过过表达和敲除几种内源性基因来尝试优化异丙醇的生产。同时过表达编码乙酰辅酶 A 合成酶和乙酰辅酶 A 乙酰转移酶的两个基因，将异丙醇的产量提高到 9.5 g/L。此外，在分批补料培养中，重组菌株从葡萄糖中生产了 27.2 g/L 的异丙醇，得率为 41.5%（摩尔/摩尔）。这是首例通过基因工程酵母生产异丙醇的报道。
