产朊假丝酵母利用不同有机酸作碳源的研究

Studies on Differential Uptake of Organic Acids by Candida utilis

分别通过不同有机酸为惟一碳源,研究了产朊假丝酵母(Candida utilis)能够利用的有机酸的种类,旨在为微生物的基础研究和应用基础研究提供部分依据。分别通过对培养时间和菌体在不同有机酸合成培养基中OD值进行统计分析,发现培养时间和柠檬酸、乳酸、琥珀酸、L-苹果酸培养基的OD值极显著相关(P<0.01);培养时间和乙酸、酒石酸、富马酸和草酸培养基的OD值无相关性。通过对比菌体培养前后有机酸合成培养基pH值的变化发现乙酸、酒石酸、富马酸和草酸合成培养基的pH值没有明显变化,而苹果酸、乳酸、琥珀酸和柠檬酸为碳源的合成培养基的pH值均明显增大。从而说明产朊假丝酵母能利用L-苹果酸、乳酸、琥珀酸、柠檬酸为碳源,而不能利用乙酸、酒石酸、草酸、富马酸为碳源。

Yeast species differ remarkably in their ability to degrade extracellular organic acids, and to utilise them as their only source of carbon . In this study, using different kinds of organic acids as the only carbon sources, we study the kinds of organic acids, which candida utilis can use. Respectively doing statistical analysis to time and OD value, we find that time and the OD value is notable interrelated（P 〈 0.01） when Candida utilis grew in the culture medium of citric acid, lactic acid, succinic acid,or malic acid. But time and the OD value is noninterrelated when Candida utilis grew in the culture medium of organic acid of acetic acid, tartaric acid, fumaric acid or oxalic acid. Through determing pH value of organic acid synthetic medium before and at the end of study, we find that the pH value of the culture medium of citric acid, acetic acid, tartaric acid, fumaric acid, oxalic acid are no obvious change; hut the pH value of the culture medium of lactic acid, succinic acid or malic acid are all increased evidently. Candida utilis can degrade extracellular citric acid , lactic acid , succinic acid, and malic acid. But it can not degrade extracellular acetic acid, tartaric acid, fumaric acid and oxalic acid.