Park Young-Kyoung, Dulermo Thierry, Ledesma-Amaro Rodrigo, Nicaud Jean-Marc
1UMR1319, Team BIMLip: Biologie Intégrative du Métabolisme Lipidique, Institut Micalis, INRA-AgroParisTech, Université Paris-Saclay, Domaine de Vilvert, 78352 Jouy-en-Josas, France.
Lesaffre International, Marcq-en-Baroeul, France.
Biotechnol Biofuels. 2018 Jun 7;11:158. doi: 10.1186/s13068-018-1154-4. eCollection 2018.
Odd chain fatty acids (odd FAs) have a wide range of applications in therapeutic and nutritional industries, as well as in chemical industries including biofuel. is an oleaginous yeast considered a preferred microorganism for the production of lipid-derived biofuels and chemicals. However, it naturally produces negligible amounts of odd chain fatty acids.
The possibility of producing odd FAs using was investigated. wild-type strain was shown able to grow on weak acids; acetate, lactate, and propionate. Maximal growth rate on propionate reached 0.24 ± 0.01 h at 2 g/L, and growth inhibition occurred at concentration above 10 g/L. Wild-type strain accumulated lipids ranging from 7.39 to 8.14% (w/w DCW) depending on the carbon source composition, and odd FAs represented only 0.01-0.12 g/L. We here proved that the deletion of the gene improved odd FAs production, which reached a ratio of 46.82% to total lipids. When this modification was transferred to an obese strain, engineered for improving lipid accumulation, further increase odd FAs production reaching a total of 0.57 g/L was shown. Finally, a fed-batch co-feeding strategy was optimized for further increase odd FAs production, which generated 0.75 g/L, the best production described so far in .
A strain able to accumulate high level of odd chain fatty acids, mainly heptadecenoic acid, has been successfully developed. In addition, a fed-batch co-feeding strategy was optimized to further improve lipid accumulation and odd chain fatty acid content. These lipids enriched in odd chain fatty acid can (1) improve the properties of the biodiesel generated from lipids and (2) be used as renewable source of odd chain fatty acid for industrial applications. This work paves the way for further improvements in odd chain fatty acids and fatty acid-derived compound production.
奇数链脂肪酸（奇数脂肪酸）在治疗和营养行业以及包括生物燃料在内的化学工业中有着广泛应用。解脂耶氏酵母是一种产油酵母，被认为是生产脂质衍生生物燃料和化学品的优选微生物。然而，它天然产生的奇数链脂肪酸数量可忽略不计。
研究了使用解脂耶氏酵母生产奇数脂肪酸的可能性。野生型菌株显示能够在弱酸（乙酸盐、乳酸盐和丙酸盐）上生长。在2 g/L时，丙酸盐上的最大生长速率达到0.24±0.01 h⁻¹，浓度高于10 g/L时出现生长抑制。野生型菌株根据碳源组成积累的脂质范围为7.39%至8.14%（w/w干重），奇数脂肪酸仅占0.01 - 0.12 g/L。我们在此证明，删除OLE1基因可提高奇数脂肪酸产量，其占总脂质的比例达到46.82%。当这种修饰转移到为改善脂质积累而改造的肥胖菌株时，显示奇数脂肪酸产量进一步增加，总计达到0.57 g/L。最后，优化了补料分批共进料策略以进一步提高奇数脂肪酸产量，该策略产生了0.75 g/L，这是目前解脂耶氏酵母中报道的最佳产量。
已成功开发出一种能够积累高水平奇数链脂肪酸（主要是十七碳烯酸）的解脂耶氏酵母菌株。此外，优化了补料分批共进料策略以进一步提高脂质积累和奇数链脂肪酸含量。这些富含奇数链脂肪酸的脂质可以（1）改善由解脂耶氏酵母脂质生成的生物柴油的性能，以及（2）用作工业应用中奇数链脂肪酸的可再生来源。这项工作为进一步提高奇数链脂肪酸和脂肪酸衍生化合物的生产铺平了道路。
