酿酒酵母呼吸缺陷型和野生型酒精发酵特性的比较分析*

比较了酒精发酵生产菌株IFFI1300及其呼吸缺陷型突变株在酒精产量、发酵动力学、耐酒精能力及与酒精发酵相关的乙醇脱氢酶活性等方面的特性。结果表明：1)发酵终期的酒精产量，45株呼吸缺陷型的平均值与野生型没有显著性差异；但部分缺陷型的酒精产量高于野生型。2)酒精发酵动力学结果显示，呼吸缺陷型酒精产生速度略高于野生型。3)单位重量干菌体的乙醇脱氢酶活性，呼吸缺陷型高于野生型。以上结果提示：呼吸缺陷型用于酒精发酵以提高酒精产量和缩短发酵周期是有潜力的。4)单位体积发酵液的乙醇脱氢酶活性则野生型高于呼吸缺陷型，主要原因在于呼吸缺陷型的生物量明显低于野生型。5)呼吸缺陷型菌株之间的耐酒精能力差别很小，耐酒精能力的高低与酒精产量的高低没有明显的正相关性。一般的，酒精产量高的菌株耐酒精能力较强。在实验结果的基础上，对呼吸缺陷型用于酒精发酵的优越性和可行性进行了讨论。

COMPARING CHARACTERISTICS OF ETHANOL PRODUCTION BY RESPIRATORY DEFICIENT MUTANTS AND WILD STRAIN IN SACCHROMYCES CEREVISIAE

In order to compare the characteristics of ethano l production, a serie s respiratory deficient mutants (rho -) of Saccharomyces cerevisiae and the ir wil d parent strain (rho +) were assayed for ethanol yield, ethanol fermentation ki netics, ethanol tolerance, and activities of ethanol-dehydrogenase. The data i nd icated that: Though the average amount of ethanol produced by mutants rho - a nd by wild rho + strains were similar, some mutants produced a little more amount of ethanol than wild type. The kinetics curve of ethanol fermentation suggested t h at rho - mutants had a little higher ethanol fermenting speeds than wild type . Th e activity of ethanol-dehydrogenase per unit weight of protein of rho - mutan ts c ells were higher than that of wild strain rho +; the activity of ethanol-dehyd rogenase per unit volume of fermentation medium of rho + were higher than that rho - mutants,mainly due to the higher biomass of rho + were higher than that of rho - mutan ts. Some rho - mutants could tolerate higher ethanol concentration than wild rh o + stra in, but some not. If higher ethanol tolerance and higher ethanol yield rho - mu tants were used in fermenting process,higher ethanol yield would be expected,but some problems such as that rho - mutants grew slowly should be considered.