Palnitkar S, Lachke A
Division of Biochemical Sciences, National Chemical Laboratory, Pune, India.
Can J Microbiol. 1992 Mar;38(3):258-60. doi: 10.1139/m92-043.
The effect on D-xylose utilization and the corresponding xylitol and ethanol production by Candida shehatae (ATCC 22984) were examined with different nitrogen sources. These included organic (urea, asparagine, and peptone) and inorganic (ammonium chloride, ammonium nitrate, ammonium sulphate, and potassium nitrate) sources. Candida shehatae did not grow on potassium nitrate. Improved ethanol production (Y(p/s), yield coefficient (grams product/grams substrate), 0.34) was observed when organic nitrogen sources were used. Correspondingly, the xylitol production was also higher with organic sources. Ammonium sulphate showed the highest ethanol:xylitol ratio (11.0) among all the nitrogen sources tested. The ratio of NADH- to NADPH-linked D-xylose reductase (EC 1.1.1.21) appeared to be rate limiting during ethanologenesis of D-xylose. The levels of xylitol dehydrogenase (EC 1.1.1.9) were also elevated in the presence of organic nitrogen sources. These results may be useful in the optimization of alcohol production by C. shehatae during continuous fermentation of D-xylose.
研究了不同氮源对嗜杀假丝酵母（ATCC 22984）利用D-木糖以及相应木糖醇和乙醇产量的影响。这些氮源包括有机氮源（尿素、天冬酰胺和蛋白胨）和无机氮源（氯化铵、硝酸铵、硫酸铵和硝酸钾）。嗜杀假丝酵母在硝酸钾上无法生长。当使用有机氮源时，乙醇产量有所提高（Y(p/s)，产率系数（克产物/克底物），0.34）。相应地，有机氮源的木糖醇产量也更高。在所有测试的氮源中，硫酸铵的乙醇:木糖醇比率最高（11.0）。在D-木糖乙醇发酵过程中，NADH连接的D-木糖还原酶与NADPH连接的D-木糖还原酶（EC 1.1.1.21）的比率似乎是限速因素。在有机氮源存在的情况下，木糖醇脱氢酶（EC 1.1.1.9）的水平也有所提高。这些结果可能有助于优化嗜杀假丝酵母在D-木糖连续发酵过程中的酒精生产。
