Britton Scott J, Rogers Lisa J, White Jane S, Neven Hedwig, Maskell Dawn L
International Centre for Brewing and Distilling, Institute of Biological Chemistry, Biophysics, and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, EH14 4AS Edinburgh, United Kingdom.
Research & Development, Brewery Duvel Moortgat, 2870 Puurs-Sint-Amands, Belgium.
FEMS Microbes. 2023 Jan 9;4:xtad002. doi: 10.1093/femsmc/xtad002. eCollection 2023.
can undergo filamentous growth in response to specific environmental stressors, particularly nitrogen-limitation, whereby cells undergo pseudohyphal differentiation, a process where cells transition from a singular ellipsoidal appearance to multicellular filamentous chains from the incomplete scission of the mother-daughter cells. Previously, it was demonstrated that filamentous growth in is co-regulated by multiple signaling networks, including the glucose-sensing RAS/cAMP-PKA and SNF pathways, the nutrient-sensing TOR pathway, the filamentous growth MAPK pathway, and the Rim101 pathway, and can be induced by quorum-sensing aromatic alcohols, such as 2-phenylethanol. However, the prevalent research on the yeast-pseudohyphal transition and its induction by aromatic alcohols in has been primarily limited to the strain Σ1278b. Due to the prospective influence of quorum sensing on commercial fermentation, the native variation of yeast-to-filamentous phenotypic transition and its induction by 2-phenylethanol in commercial brewing strains was investigated. Image analysis software was exploited to enumerate the magnitude of whole colony filamentation in 16 commercial strains cultured on nitrogen-limiting SLAD medium; some supplemented with exogenous 2-phenylethanol. The results demonstrate that phenotypic switching is a generalized, highly varied response occurring only in select brewing strains. Nevertheless, strains exhibiting switching behavior altered their filamentation response to exogenous concentrations of 2-phenylethanol.
在特定环境应激源，特别是氮限制的情况下，细胞可进行丝状生长，在此过程中细胞会经历假菌丝分化，即细胞从单个椭圆形外观转变为多细胞丝状链，这是母细胞与子细胞不完全分裂的过程。此前已证明，细胞的丝状生长由多个信号网络共同调节，包括葡萄糖感应的RAS/cAMP-PKA和SNF途径、营养感应的TOR途径、丝状生长MAPK途径以及Rim101途径，并且可由群体感应芳香醇（如2-苯乙醇）诱导。然而，关于酿酒酵母假菌丝转变及其在酿酒酵母中由芳香醇诱导的研究主要局限于Σ1278b菌株。由于群体感应对商业发酵的潜在影响，研究了商业酿造菌株中酵母到丝状表型转变的天然变异及其由2-苯乙醇诱导的情况。利用图像分析软件对在氮限制的SLAD培养基上培养的16种商业菌株（有些添加了外源2-苯乙醇）的全菌落丝状化程度进行计数。结果表明，表型转换是一种普遍存在且高度可变的反应，仅在特定的酿造菌株中出现。然而，表现出转换行为的菌株改变了它们对外源2-苯乙醇浓度的丝状化反应。
