Ethanol and phenylacetylcarbinol production processes of Candida tropicalis TISTR 5306 and Saccharomyces cerevisiae TISTR 5606 in fresh juices from longan fruit of various sizes

摘要

Fresh juice from C grade longan (mg/g fresh fruit; total sugars 51.6 ± 0.5, nitrogen0.021 ± 0.004; gallic acid 0.025 ± 0.001; ellagic acid 0.016 ± 0.001) with addition of8.52 g ammonium sulfate/l was the optimal medium for cultivation processes ofSaccharomyces cerevisiae TISTR 5606 and Candida tropicalis TISTR 5306 capable ofproducing ethanol and phenylacetylcarbinol (PAC) among five longan grades. S. cerevisiaeTISTR 5606 produced ethanol (33.4 ± 3.2 g/L) at a significantly higher level (p ≤ 0.05)than C. tropicalis TISTR 5306 (22.3 ± 1.1 g/L) with similar ethanol yields (Y_(p/s)) between0.21 and 0.22 g ethanol produced/g sugars consumed. Whole cells of C. tropicalis TISTR5306 produced a significantly higher (p ≤ 0.05) PAC level (27.2 ± 0.7 mM) than S. cerevisiaeTISTR 5606 (3.59 ± 1.33 mM) after 6 hr in an equivalent volume biphasic biotransformationsystem.