Downloaded from www.microbiologyresearch.org by IP: 54.191.40.80 On: Fri, 25 Aug 2017 15:32:16 Journal of General Microbiology ( 1987), 133, 2 18 1-2 190. Printed in Great Britain 2181 Production of Long-chain Alcohols by Yeasts By MICHAEL J. WHITE,' ROGER C. HAMMOND2 AND ANTHONY H. ROSE1* ' Zyrnology Laboratory, School of Biological Sciences, Bath University, Bath, Avon BA2 7AY, UK Unilever Research Laboratory, Colworth Laboratory, Colworth House, Sharnbrook, Bedford MK44 ILQ, UK (Received 16 February 1987; revised 12 March 1987) Fourteen yeast strains from six genera were analysed for the presence of long-chain alcohols. Six strains from three genera contained long-chain alcohols, highest levels being found in Candida afbicans. The alcohols were identified and determined by TLC, GLC and GLC-MS. The major long-chain alcohols synthesized by these organisms were saturated, primary alcohols with C1 4, CI6 or C18 chain length. Unsaturated long-chain alcohols were not detected. In all strains that produced long-chain alcohols, the relative proportions were C I 6 > C18 > C14. Long-chain alcohol contents were higher in organisms from anaerobically, as compared with aerobically, grown cultures reaching about 650 pg (g dry wt organisms)-' in stationary-phase cultures of C. afbicans. In cultures of C. albicans, synthesis of long-chain alcohols occurred only after the end of exponential growth. The alcohols were predominantly present as free alcohols. The fatty-acyl chain-length profile of the triacylglycerol and to a lesser extent the sterol/wax ester fractions from C . albicans reflected that of the long-chain alcohols produced by this yeast. INTRODUCTION Long-chain alcohols occur as components of animal, higher plant and microbial lipids as free alcohols, precursors of glycerol ether lipids and in combination with carboxylic acids as wax esters (Mahadevan, 1978 ; Harwd & Russell, 1984). Among micro-organisms that synthesize long-chain alcohols, bacteria have been studied most intensively (Stewart & Kallio, 1959; Raymond & Davis, 1960; Baptist et al., 1963 ; Day et al., 1970 ; Allen et af., 197 1 ; Naccarato et af., 1972; Lloyd & Russell, 1983). Some long-chain alcohol-containing bacteria, such as mycobacteria (Ratledge, 1976), have been studied because of their medical importance. Other bacteria have been investigated for their industrial importance in, for example, degradation of oil spillage (Higgins & Gilbert, 1978). In oil-degrading micro-organisms, long-chain alcohols are produced as intermediates in terminal oxidation of alkanes, and may also be found esterified with long-chain carboxylic acids which are produced by further oxidation of the alcohols (Ratledge, 1978; Britton, 1984). When grown on carbon sources other than alkanes, some bacteria synthesize long-chain primary alcohols by reduction of CoA esters of long-chain carboxylic acids which arise either from activity of the fatty acid synthase (Day et al., 1970; Naccarato et al., 1972; Lloyd & Russell, 1983) or are supplied exogenously (Naccarato et al., 1974; Lloyd & Russell, 1983). Some yeasts are able to grow on alkanes (Britton, 1984) and certain of these organisms may accumulate wax esters containing long-chain alcohols. These yeasts include Candida guilliermondii (Muratov et al., 1979) and Rhodotorula glutinis (Zalashko et al., 1979; Zalashko & Salokhina, 1982). Reports of long-chain alcohol production by yeasts grown on non-alkane Abbreviations: PCMB, pchloromercuribenzoate; TMS ethers, trimethylsilyl ethers. 0001-4006 0 1987 SGM