Thermo-and salt-tolerant <i>Saccharomyces cerevisiae</i> strains isolated from fermenting coconut toddy from Sri Lanka

‘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 <i>Saccharomyces cerevisiae</i>, while eight strains showed 99% identity to <i>Pichia manshurica</i> and a single isolate showed 99% identity to <i>Saccharomycodes ludwigii</i>. Regarding salt tolerance, all isolated strains of <i>S. cerevisiae</i> 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 <i>S. cerevisiae</i> strains showed significant growth even at 42 °C. All the 18 <i>S. cerevisiae</i> strains still showed growth better than reference strains did in a medium with 7.5% (w/v) NaCl at 40 °C. All <i>S. cerevisiae</i> isolates produced relatively high alcohol concentrations than reference strains did when growing on batch-fermented media with 100 g·L⁻¹glucose 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 g·L⁻¹ glucose than with 100 g·L⁻¹glucose, significantly at 45 °C.

椰花酒（Toddy）是一种由植物韧皮部汁液自然发酵制得的酒精饮品。本研究从斯里兰卡的椰花酒中分离得到27株酵母菌。对其中18株菌株的26S rDNA基因D1/D2区域序列进行测序分析，结果显示其与酿酒酵母（Saccharomyces cerevisiae）的同源性达100%；另有8株菌株与曼苏尔毕赤酵母（Pichia manshurica）同源性为99%，剩余1株菌株与路德类酵母（Saccharomycodes ludwigii）同源性为99%。关于耐盐性：所有分离得到的酿酒酵母菌株均可在含10.0%（w/v）氯化钠的酵母提取物-蛋白胨-葡萄糖（YPD）培养基中生长，其中菌株SLY-10甚至可在13.0%（w/v）氯化钠条件下生长增殖。所有分离菌株均可在40℃条件下良好生长，且18株酿酒酵母甚至可在42℃下实现显著增殖。在40℃、含7.5%（w/v）氯化钠的培养基中，18株酿酒酵母的生长状况仍优于参考菌株。在40℃、初始葡萄糖浓度为100 g·L⁻¹的分批发酵培养基中培养时，所有酿酒酵母分离株的酒精产量均高于参考菌株。菌株SLY-3、SLY-4、SLY-8、SLY-9及SLY-10甚至可在45℃下实现可观的酒精产量：在两种不同葡萄糖浓度条件下，40℃与45℃下24小时的酒精产率基本一致；当葡萄糖浓度为160 g·L⁻¹时，酒精产量高于100 g·L⁻¹组，且该差异在45℃下尤为显著。

搜集汇总

背景与挑战

背景概述

该数据集包含从斯里兰卡椰子酒发酵过程中分离的27株酵母菌株，其中18株被鉴定为Saccharomyces cerevisiae，这些菌株表现出显著的耐盐和耐热特性，能在高浓度NaCl（最高13.0%）和高温（最高45°C）条件下生长，并在高温发酵中产生较高的酒精浓度，适用于生物技术和发酵研究。