Yamada Ryosuke, Kashihara Tomomi, Ogino Hiroyasu
Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
World J Microbiol Biotechnol. 2017 May;33(5):99. doi: 10.1007/s11274-017-2269-7. Epub 2017 Apr 20.
Oleaginous yeasts are considered a promising alternative lipid source for biodiesel fuel production. In this study, we attempted to improve the lipid productivity of the oleaginous yeast Rhodosporidium toruloides through UV irradiation mutagenesis and selection based on ethanol and HO tolerance or cerulenin, a fatty acid synthetase inhibitor. Glucose consumption, cell growth, and lipid production of mutants were evaluated. The transcription level of genes involved in lipid production was also evaluated in mutants. The ethanol and HO tolerant strain 8766 2-31M and the cerulenin resistant strain 8766 3-11C were generated by UV mutagenesis. The 8766 2-31M mutant showed a higher lipid production rate, and the 8766 3-11C mutant produced a larger amount of lipid and had a higher lipid production rate than the wild type strain. Transcriptional analysis revealed that, similar to the wild type strain, the ACL1 and GND1 genes were expressed at significantly low levels, whereas IDP1 and ME1 were highly expressed. In conclusion, lipid productivity in the oleaginous yeast R. toruloides was successfully improved via UV mutagenesis and selection. The study also identified target genes for improving lipid productivity through gene recombination.
产油酵母被认为是生物柴油燃料生产中一种有前景的替代脂质来源。在本研究中，我们试图通过紫外线照射诱变，并基于对乙醇和过氧化氢的耐受性或脂肪酸合成酶抑制剂浅蓝菌素进行筛选，来提高产油酵母红冬孢酵母的脂质生产率。评估了突变体的葡萄糖消耗、细胞生长和脂质产量。还评估了突变体中参与脂质生产的基因的转录水平。通过紫外线诱变产生了耐乙醇和过氧化氢的菌株8766 2 - 31M以及抗浅蓝菌素的菌株8766 3 - 11C。8766 2 - 31M突变体显示出较高的脂质生产率，并且8766 3 - 11C突变体比野生型菌株产生了更多的脂质且脂质生产率更高。转录分析表明，与野生型菌株相似，ACL1和GND1基因表达水平显著较低，而IDP1和ME1高度表达。总之，通过紫外线诱变和筛选成功提高了产油酵母红冬孢酵母的脂质生产率。该研究还确定了通过基因重组提高脂质生产率的靶基因。
