Biotechnology Process Engineering Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji-ro, Cheongwon-gu, Cheongju-si, Chungcheongbuk-do 28116, Republic of Korea.
Interdisciplinary Program for Bioengineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
FEMS Yeast Res. 2020 Mar 1;20(2). doi: 10.1093/femsyr/foaa011.
Yarrowia lipolytica is a non-conventional, heterothallic, oleaginous yeast with wide range of industrial applications. Increasing ploidy can improve advantageous traits for industrial applications including genetic stability, stress resistance, and productivity, but the construction of knockout mutant strains from polyploid cells requires significant effort due to the increased copy numbers of target genes. The goal of this study was to evaluate the effectiveness of a mating-type switching strategy by single-step transformation without a genetic manipulation vestige, and to optimize the conventional method for increasing ploidy (mating) in Y. lipolytica. In this study, mating-type genes in haploid Y. lipolytica cells were scarlessly converted into the opposite type genes by site-specific homologous recombination, and the resulting MATB-type cells were mated at low temperature (22°C) with addition of sodium citrate with each MATA-type haploid cell to yield a MATA/MATB-type diploid strain with genetic information from both parental strains. The results of this study can be used to increase ploidy and for whole genome engineering of a yeast strain with unparalleled versatility for industrial application.
解脂耶氏酵母是一种非常规的、异型接合的、产油酵母，具有广泛的工业应用。增加倍性可以提高遗传稳定性、抗逆性和生产力等工业应用的有利特性，但由于靶基因的拷贝数增加，从多倍体细胞中构建敲除突变株需要大量的工作。本研究旨在评估单步转化不依赖遗传操作痕迹的交配型转换策略的有效性，并优化解脂耶氏酵母中增加倍性（交配）的常规方法。在这项研究中，通过位点特异性同源重组，将单倍体解脂耶氏酵母细胞中的交配型基因无痕转化为相反类型的基因，然后将得到的 MATB 型细胞在低温（22°C）下与添加柠檬酸钠的每个 MATA 型单倍体细胞交配，生成具有来自双亲本的遗传信息的 MATA/MATB 型二倍体菌株。这项研究的结果可用于增加倍性，并对酵母菌株进行全基因组工程改造，为工业应用提供无与伦比的多功能性。
