PRODUCTION OF FATTY ACIDS AND LIPID BY A CANDIDA SP GROWING ON A FRACTION OF N-ALKANES PREDOMINATING IN TRIDECANE

A Candida sp. was grown on a fraction of n‐alkanes (dodecane 22%, tridecane 48%, tetradecane 28%) as sole carbon source. The growth rate was increased most markedly by using high concentrations of n‐alkanes (16.7% v/v). When grown in a 5 liter fermentor, the yeast reached its highest yield (60 g. of cell dry wt/l) with a concomitant high yield of fatty acids (21 g of fatty acids/l), by using a nitrogen‐deficient medium. To achieve good growth, it was essential to use an inoculum (1 part into 10) of rapidly growing cells and beneficial to increase the agitation rate gradually once growth had begun. After 108 hr maximum conversions of substrate to product were: 71.5% (w/w) for alkanes into cells and 24.8% (w/w) for alkanes into fatty acids. Of the, total fatty acids at the end of the fat‐accumulating phase of growth 54% were shorter in chain length than palmitic acid (C16H32O2). When grown on glucose, as sole carbon source, less than 2% of the total fatty acids were shorter than palmitic acid. When n‐alkanes were added to cells growing on glucose, short‐chain fatty acids (C10 to C14) were synthesized immediately, indicating a derepressed enzyme system for hydrocarbon assimilation and the absence of diauxie. The production of these acids was at the apparent sacrifice of linoleic acid synthesis. In spite of the high conversion ratios, it is concluded that it would be uneconomical to produce fatty acids, even expensive ones such as lauric acid, by microbial transformation of n‐alkanes. Copyright © 1968 John Wiley & Sons, Inc.