We previously isolated 18 Saccharomyces cerevisiae strains from coconut toddy in Sri Lanka. All the 18 strains (SLY-1 to SLY-18) could grow aerobically up to 18 mmol L À1 vanillin in yeast extract-peptone-dextrose (YPD) medium, and the SLY-10 strain showed the highest vanillin tolerance (up to 21 mmol L À1 ). Among these 18 strains, even in the presence of 24 mmol L À1 vanillin, five strains (SLY-3, SLY-4, SLY-8, SLY-9 and SLY-10) produced alcohol at 72 h in the range of 11.4-33.1 g L À1 and the SLY-10 strain showed highest alcohol production. The five strains showed the conversion of vanillin to vanillyl alcohol. They also tolerated other strong inhibitors: 4-hydroxybenzoic acid (24 mmol L À1 ), furfural (30 mmol L À1 ), 5-hydroxymethyl-2-furaldehyde (5-HMF, 36 mmol L À1 ) and acetic acid (75 mmol L À1 ). All these five strains showed no growth and no alcohol production when cultured in the medium with inhibitor mixture of 2.7 mmol L À1 vanillin, 30 mmol L À1 furfural, 30 mmol L À1 5-HMF, 75 mmol L À1 acetic acid and 75 mmol L À1 formic acid but showed significant growth and alcohol production of 16.2-32.7 g L À1 with inhibitor mixture of 30% concentration (0.81 mmol L À1 vanillin, 9 mmol L À1 furfural, 9 mmol L À1 5-HMF, 22.5 mmol L À1 acetic acid and 22.5 mmol L À1 formic acid). The four strains (SLY-3, SLY-4, SLY-8 and SLY-9) were shown to tolerate the inhibitor mixture to a similar extent and better than SLY-10, while SLY-10 was the best to vanillin alone. ARTICLE HISTORY

'Toddy' is an alcoholic beverage obtained by the natural fermentation of phloem sap. We isolated 27 yeast strains from coconut toddy in Sri Lanka. Sequences of the 26S rDNA gene D1/D2 region from 18 strains showed 100% identity to Saccharomyces cerevisiae, while eight strains showed 99% identity to Pichia manshurica and a single isolate showed 99% identity to Saccharomycodes ludwigii. Regarding salt tolerance, all isolated strains of S. cerevisiae were found to grow in the presence of 10.0% (w/v) NaCl in yeast extract-peptone-dextrose (YPD), one of the isolates (SLY-10) grew even with 13.0% (w/v) NaCl. All the isolates grew well at 40 C, and the 18 S. cerevisiae strains showed significant growth even at 42 C. All the 18 S. cerevisiae strains still showed growth better than reference strains did in a medium with 7.5% (w/v) NaCl at 40 C. All S. cerevisiae isolates produced relatively high alcohol concentrations than reference strains did when growing on batch-fermented media with 100 gÁL À1 glucose in at 40 C. The five strains (SLY-3, SLY-4, SLY-8, SLY-9 and SLY-10) produced significant amounts of alcohol even at 45 C: alcohol productivity over 24 h at 40 C and 45 C was similar in two different glucose concentrations, and the amount of produced alcohol was higher with 160 gÁL À1 glucose than with 100 gÁL À1 glucose, significantly at 45 C.