Microbial reduction using ethanol as an energy source

前手性酮的微生物还原被认为是一种制备手性仲醇的有效方法。最近，一种以乙醇代替糖为能源的酵母介导的面包师生物还原新工艺被开发出来。本研究旨在研究以乙醇为能源的微生物还原，并研究培养条件与还原能力的关系。1.以乙醇为能源的微生物的筛选与生物还原多年来的许多供试菌株以乙醇和/或醋酸盐为能源，以葡萄糖为能源进行NAD(P)H的生物还原。然后，模具只使用葡萄糖作为能源，而不使用乙醇或醋酸酯。另一方面，一些细菌有效地利用乙醇而不是葡萄糖。研究了在酵母细胞中通过乙醇的氧化途径从相应的氧化形式中再生NAD(P)H的方案。2.以乙醇为能源再生NAD(P)H的能力与培养条件对吸氧率的关系。酵母菌7099在较厌氧条件下培养，以乙醇为能源再生NAD(P)H的能力较低。这与乙醛脱氢酶活性较低有关，但乙醇脱氢酶活性不受该培养条件的影响。

The microbial reduction of prochiral ketones has been recognaized as a useful technique to prepare a chiral secondary alcohols. Recently, a new procedure for the baker's yeast-mediated bioreduction using ethanol instead of sugar as the energy source was developed. This research is to study the microbial reduction using ethanol as the energy source and to study the relation between culitivation conditions and the reduction ability.1.Screening of microbials using ethanol as an energy source for NAD(P)H regneration coupled with a bioreductionMany of the tested strains of years use ethanol and/or acetate as an energy source for NAD(P)H regneration coupled with a bioreduction in the same manner as glucose. Then, molds use only glucose as the energy source but ethanol or acetate. On the other hand, some of bacterias use ethanol effectively but glucose.A scheme for NAD(P)H regeneration from the corresponding oxidezed from through the oxidative pathway of ethanol in yeast cells was studied. THe results suggested tha NADH was regenerated through alcoholic oxidation into acetate and NADPH through acetate oxidation into carbon cioxide.2.Relationship between the ability using ethanol as energy sourcet for NAD(P)H regeneration and the culture condition on oxygen absorption rate.Yeasts, Saccharomysex cerevisiae HUT 7099, cultured under more anaerobic conditions had the lower ablity using ethanol as energy source for NAD(P)H regeneration. The reason was related to lower activity of aldehyde dehydrogenase though the activity of alcohol dehydrogenase was not influensed by such culture conditions.