Data underlying the study on Engineering Saccharomyces cerevisiae for fast vitamin-independent aerobic growth

Chemically defined media for cultivation of <em>Saccharomyces cerevisiae </em>strains are commonly supplemented with a mixture of multiple Class-B vitamins, whose omission leads to strongly reduced growth rates. Fast growth without vitamin supplementation is interesting for industrial applications, as it reduces costs and complexity of medium preparation and may decrease susceptibility to contamination by auxotrophic microbes. In this study, suboptimal growth rates of <em style="color:rgb(33, 33, 33);">S. cerevisiae</em> CEN.PK113-7D in the absence of pantothenic acid, <em style="color:rgb(33, 33, 33);">para</em>-aminobenzoic acid (<em style="color:rgb(33, 33, 33);">p</em>ABA), pyridoxine, inositol and/or biotin were corrected by single or combined overexpression of <em style="color:rgb(33, 33, 33);">ScFMS1</em>, <em style="color:rgb(33, 33, 33);">ScABZ1</em>/<em style="color:rgb(33, 33, 33);">ScABZ2</em>, <em style="color:rgb(33, 33, 33);">ScSNZ1</em>/<em style="color:rgb(33, 33, 33);">ScSNO1</em>, S<em style="color:rgb(33, 33, 33);">cINO1</em> and <em style="color:rgb(33, 33, 33);">Cyberlindnera fabianii BIO1</em>, respectively. Several strategies were explored to improve growth of <em style="color:rgb(33, 33, 33);">S. cerevisiae</em> CEN.PK113-7D in thiamine-free medium. Overexpression of <em style="color:rgb(33, 33, 33);">ScTHI4</em> and/or <em style="color:rgb(33, 33, 33);">ScTHI5</em> enabled thiamine-independent growth at 83% of the maximum specific growth rate of the reference strain in vitamin-supplemented medium. Combined overexpression of seven native <em style="color:rgb(33, 33, 33);">S. cerevisiae</em> genes and <em style="color:rgb(33, 33, 33);">CfBIO1</em> enabled a maximum specific growth rate of 0.33 ± 0.01 h^-1 in vitamin-free synthetic medium. This specific growth rate was only 18 % lower than that of a congenic reference strain in vitamin-supplemented medium. Physiological parameters of the engineered vitamin-independent strain in aerobic glucose-limited chemostat cultures (dilution rate 0.10 h^-1) grown on vitamin-free synthetic medium were similar to those of similar cultures of the parental strain grown on vitamin-supplemented medium. Transcriptome analysis revealed only few differences in gene expression between these cultures, which primarily involved genes with roles in Class-B vitamin metabolism. These results pave the way for development of fast-growing vitamin-independent industrial strains of <em>S. cerevisiae</em>.

用于培养酿酒酵母（Saccharomyces cerevisiae）菌株的化学成分限定培养基，通常需添加多种B族维生素（Class-B vitamins）的混合物；若省略该添加剂，则菌株生长速率会显著降低。无需额外添加维生素即可实现快速生长，在工业应用中极具价值——这不仅能降低培养基制备的成本与复杂度，还可降低营养缺陷型微生物污染的风险。本研究中，酿酒酵母CEN.PK113-7D在缺乏泛酸（pantothenic acid）、对氨基苯甲酸（para-aminobenzoic acid, pABA）、吡哆醇（pyridoxine）、肌醇（inositol）和/或生物素（biotin）时的亚最优生长速率，可通过分别或联合过表达ScFMS1、ScABZ1/ScABZ2、ScSNZ1/ScSNO1、ScINO1以及费比恩类林达酵母BIO1（Cyberlindnera fabianii BIO1）得以矫正。本研究还探索了多种策略，以提升酿酒酵母CEN.PK113-7D在不含硫胺素（thiamine）培养基中的生长能力。过表达ScTHI4和/或ScTHI5可使菌株在不依赖硫胺素的条件下生长，其最大比生长速率可达维生素补充型参考菌株的83%。联合过表达7个酿酒酵母内源基因与CfBIO1后，菌株在无维生素合成培养基中的最大比生长速率可达0.33 ± 0.01 h⁻¹，仅比维生素补充型同基因背景参考菌株低18%。在以葡萄糖为限制性底物的有氧恒化培养（稀释率0.10 h⁻¹）中，工程化维生素非依赖型菌株在无维生素合成培养基上的生理参数，与亲本菌株在维生素补充型培养基上的同类培养物基本一致。转录组分析（transcriptome analysis）显示，二者的基因表达差异仅寥寥数种，且主要涉及B族维生素代谢相关基因。上述研究结果为构建快速生长、无需维生素的工业酿酒酵母菌株铺平了道路。