Studies on Differential Uptake of Organic Acids by Candida utilis

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(P0.01)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;but 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.