Wang Chunxiao, Mas Albert, Esteve-Zarzoso Braulio
Departament de Bioquímica i Biotecnologia, Universitat Rovira i Virgili Tarragona, Spain.
Front Microbiol. 2016 Apr 13;7:502. doi: 10.3389/fmicb.2016.00502. eCollection 2016.
The present study analyzes the lack of culturability of different non-Saccharomyces strains due to interaction with Saccharomyces cerevisiae during alcoholic fermentation. Interaction was followed in mixed fermentations with 1:1 inoculation of S. cerevisiae and ten non-Saccharomyces strains. Starmerella bacillaris, and Torulaspora delbrueckii indicated longer coexistence in mixed fermentations compared with Hanseniaspora uvarum and Metschnikowia pulcherrima. Strain differences in culturability and nutrient consumption (glucose, alanine, ammonium, arginine, or glutamine) were found within each species in mixed fermentation with S. cerevisiae. The interaction was further analyzed using cell-free supernatant from S. cerevisiae and synthetic media mimicking both single fermentations with S. cerevisiae and using mixed fermentations with the corresponding non-Saccharomyces species. Cell-free S. cerevisiae supernatants induced faster culturability loss than synthetic media corresponding to the same fermentation stage. This demonstrated that some metabolites produced by S. cerevisiae played the main role in the decreased culturability of the other non-Saccharomyces yeasts. However, changes in the concentrations of main metabolites had also an effect. Culturability differences were observed among species and strains in culture assays and thus showed distinct tolerance to S. cerevisiae metabolites and fermentation environment. Viability kit and recovery analyses on non-culturable cells verified the existence of viable but not-culturable status. These findings are discussed in the context of interaction between non-Saccharomyces and S. cerevisiae.
本研究分析了在酒精发酵过程中，不同非酿酒酵母菌株与酿酒酵母相互作用导致的可培养性缺失。在酿酒酵母和十种非酿酒酵母菌株以1:1接种的混合发酵中追踪相互作用情况。与葡萄汁有孢汉逊酵母和美丽梅奇酵母相比，巴氏有孢圆酵母和戴尔布有孢圆酵母在混合发酵中显示出更长的共存时间。在与酿酒酵母的混合发酵中，发现每个物种内的菌株在可培养性和营养消耗（葡萄糖、丙氨酸、铵、精氨酸或谷氨酰胺）方面存在差异。使用酿酒酵母的无细胞上清液和模拟酿酒酵母单发酵以及与相应非酿酒酵母物种的混合发酵的合成培养基进一步分析这种相互作用。与对应相同发酵阶段的合成培养基相比，酿酒酵母无细胞上清液诱导可培养性丧失更快。这表明酿酒酵母产生的一些代谢物在其他非酿酒酵母的可培养性降低中起主要作用。然而，主要代谢物浓度的变化也有影响。在培养试验中观察到物种和菌株之间的可培养性差异，因此显示出对酿酒酵母代谢物和发酵环境的不同耐受性。对不可培养细胞的活力试剂盒和复苏分析证实了活但不可培养状态的存在。在非酿酒酵母和酿酒酵母相互作用的背景下讨论了这些发现。
