Limtong Savitree, Am-In Somjit, Kaewwichian Rungluk, Kaewkrajay Chutima, Jindamorakot Sasitorn
Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand.
Academy of Science, Royal Society of Thailand, Bangkok, 10300, Thailand.
Antonie Van Leeuwenhoek. 2020 Dec;113(12):2077-2095. doi: 10.1007/s10482-020-01479-2. Epub 2020 Oct 20.
This study aimed to explore communities and the ethanol-fermenting ability of yeasts in fresh coconut, palmyra, and nipa palm saps. From the 90 samples of coconut, palmyra, and nipa palm saps, 204 yeast isolates were isolated and identified as 15 species in the phylum Ascomycota and a species (one strain) in Basidiomycota. Saccharomyces cerevisiae, Hanseniaspora guilliermondii, and Lachancea thermotolerans were found in the saps of all three palm species. Candida tropicalis and Pichia kudriavzevii were obtained from the coconut and palmyra palm saps, Hanseniaspora vineae, Lachancea fermentati, and Pichia manshurica were present in the coconut and nipa palm saps, whereas Torulaspora delbrueckii was found in the palmyra and nipa palm saps. The species with the highest occurrence in the saps of coconut, palmyra, and nipa palms was S. cerevisiae with 76.67%, 86.70%, and 100% frequency of occurrence, respectively. Using principal coordinates analysis for ordination, no marked difference was observed in the yeast communities from the saps of the three palm species. A total of 199 isolates were found to possess ethanol-fermentation ability when cultivated using shake flask in 160 g/L of glucose medium at 28°C for 48 h. Lachancea fermentati YSP-383, isolated from nipa palm sap, produced the highest amount of ethanol (76.74 g/L). Twenty-six isolates of Candida sanyaensis (1), C. tropicalis (1), H. guilliermondii (7), L. fermentati (8), L. thermotolerans (1), Pichia kudriavzevii (2), and S. cerevisiae (6) produced high amounts of ethanol ranging from 69.57 to 76.74 g/L. The result demonstrated that yeasts in the palm saps could play roles in the natural fermentation of palm saps.
本研究旨在探索新鲜椰子、扇叶树头榈和尼帕榈树液中的酵母群落及其乙醇发酵能力。从90份椰子、扇叶树头榈和尼帕榈树液样本中，分离出204株酵母菌株，鉴定为子囊菌门的15个种和担子菌门的1个种（1株）。在所有三种棕榈树的树液中均发现了酿酒酵母、季也蒙毕赤酵母和耐热有孢汉逊酵母。热带假丝酵母和库德里阿兹威毕赤酵母从椰子和扇叶树头榈树液中分离得到，葡萄汁有孢汉逊酵母、发酵有孢圆酵母和曼氏毕赤酵母存在于椰子和尼帕榈树液中，而德巴利有孢圆酵母在扇叶树头榈和尼帕榈树液中被发现。在椰子、扇叶树头榈和尼帕榈树液中出现频率最高的物种是酿酒酵母，其出现频率分别为76.67%、86.70%和100%。使用主坐标分析进行排序，未观察到三种棕榈树树液中的酵母群落有明显差异。当在28℃下于160 g/L葡萄糖培养基中使用摇瓶培养48 h时，共发现199株菌株具有乙醇发酵能力。从尼帕榈树液中分离出的发酵有孢圆酵母YSP-383产生的乙醇量最高（76.74 g/L）。26株三亚假丝酵母（1株）、热带假丝酵母（1株）、季也蒙毕赤酵母（7株）、发酵有孢圆酵母（8株）、耐热有孢汉逊酵母（1株）、库德里阿兹威毕赤酵母（2株）和酿酒酵母（6株）产生的乙醇量较高，范围为69.57至76.74 g/L。结果表明，棕榈树液中的酵母可能在棕榈树液的自然发酵中发挥作用。
