Division of Systems and Synthetic Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden.
PLoS One. 2020 Apr 3;15(4):e0231161. doi: 10.1371/journal.pone.0231161. eCollection 2020.
There is a need for development of sustainable production processes for production of fats/oils and lipid derived chemicals. The dimorphic oleaginous yeast Yarrowia lipolytica is a promising organism for conversion of biomass hydrolysate to lipids, but in many such processes hyphae formation will be problematic. We have therefore constructed and compared the performance of strains carrying deletions in several published gene targets suggested to abolish hyphae formation (MHY1, HOY1 and CLA4). The MHY1-deletion was the only of the tested strains which did not exhibit hyphae formation under any of the conditions tested. The MHY1-deletion also had a weak positive effect on lipid accumulation without affecting the total fatty acid composition, irrespective of the nitrogen source used. MHY1 has been suggested to constitute a functional homolog of the stress responsive transcription factors MSN2/4 in Saccharomyces cerevisiae, the deletion of which are highly stress sensitive. However, the deletion of MHY1 displayed only minor difference on survival of a range of acute or long term stress and starvation conditions. We conclude that the deletion of MHY1 in Y.lipolytica is a reliable way of abolishing hyphae formation with few detectable negative side effects regarding growth, stress tolerance and lipid accumulation and composition.
需要开发可持续的生产工艺来生产油脂和衍生自脂质的化学品。两型态产油酵母解脂耶氏酵母是将生物质水解物转化为脂质的有前途的生物，但在许多此类过程中，菌丝形成将是一个问题。因此，我们构建并比较了携带几种已发表的基因靶点缺失的菌株的性能，这些基因靶点被认为可以消除菌丝形成（MHY1、HOY1 和 CLA4）。在测试的菌株中，只有 MHY1 缺失菌株在测试的任何条件下都不会形成菌丝。MHY1 缺失对脂质积累也有微弱的积极影响，而不影响总脂肪酸组成，无论使用何种氮源。MHY1 被认为构成了酿酒酵母中应激响应转录因子 MSN2/4 的功能同源物，其缺失对压力高度敏感。然而，MHY1 的缺失在一系列急性或长期应激和饥饿条件下的存活中仅显示出微小的差异。我们得出结论，在解脂耶氏酵母中缺失 MHY1 是一种可靠的方法，可以消除菌丝形成，而对生长、应激耐受性和脂质积累和组成几乎没有可检测的负面影响。
