Cultivation of the yeast candida lipolytica on hydrocarbons. I. Degradation of n‐alkanes in batch fermentation of gas oil

Abstract

The growth of batch‐cultivated yeast Candida lipolytica on three kinds of gas oil using mineral medium was studied. A linear dependence was found between the production of yeast biomass and the consumption of n‐alkanes, while the decrease of freezing point of gas oil during cultivation had a distinct course. This disproportion was explained by different degradation of individual n‐alkanes contained in gas oil. The rate of degradation of pentadecane, hexadecane, and heptadecane was the same during the entire cultivation. On the contrary, in the first phase the utilization of shorter chain n‐alkanes, nonane to tetradecane, was more rapid while that of longer chain homologs, octadecane to pentacosane, lagged. Rapid utilization of longer chain n‐alkanes did not occur before the concentration of the other n‐alkanes decreased. Only then the rapid decrease of freezing point appeared.