Optimization of odd chain fatty acid production by Yarrowia lipolytica

Abstract

BackgroundOdd chain fatty acids (odd FAs) have a wide range of applications in therapeutic and nutritional industries, as well as in chemical industries including biofuel. Yarrowia lipolytica 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.ResultsThe possibility of producing odd FAs using Y. lipolytica was investigated. Y. lipolytica 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−1 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 PHD1 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 Y. lipolytica.ConclusionsA Y. lipolytica 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 Y. lipolytica 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.Electronic supplementary materialThe online version of this article (10.1186/s13068-018-1154-4) contains supplementary material, which is available to authorized users.

Screening a genomic library for genes involved in propionate tolerance in Yarrowia lipolytica

“…As shown in a previous study (Park et al, ), propionate is an important substrate for lipid synthesis in Y . lipolytica , especially when it comes to the production of odd‐chain FAs.…”

“…These effects have been observed in several studies of lipid production employing Y . lipolytica (Fontanille et al, ; Kolouchova et al, 2015; Park et al, ). Our previous study showed that propionate inhibited the growth of a WT strain: The growth rate was 0.236 hr −1 in 2 g/L propionate medium and dropped to 0.029 hr −1 in 100 g/L propionate medium (Park et al, ).…”

“…lipolytica (Fontanille et al, ; Kolouchova et al, 2015; Park et al, ). Our previous study showed that propionate inhibited the growth of a WT strain: The growth rate was 0.236 hr −1 in 2 g/L propionate medium and dropped to 0.029 hr −1 in 100 g/L propionate medium (Park et al, ). For this reason, it will be necessary to improve microbial resistance to propionate and other weak acids if they are to be used as substrates in lipid production.…”

“…Propionate, one of the most common VFAs, can be used by Yarrowia lipolytica as its sole carbon source in lipid production (Fontanille, Kumar, Christophe, Nouaille, & Larroche, 2012;Kolouchová, Schreiberová, Sigler, Masák, & Řezanka, 2015;Gao et al, 2017). Recently, Y. lipolytica was metabolically engineered to produce unusual lipids, namely, odd-chain FAs, using propionate (Park, Dulermo, Ledesma-Amaro, & Nicaud, 2018). In the wild-type (WT) strain, lipid content ranged from 7.39% to 8.14% (w/w dry cell weight [DCW]), depending on the composition of the carbon source, and oddchain FAs represented 22.9% to 36.5% of total lipids, corresponding to a concentration of 0.01-0.12 g/L.…”

Volatile fatty acids as novel building blocks for oil‐based chemistry via oleaginous yeast fermentation

“…On the other hand, a higher lipid content and yield in C. albidus was promoted by predominance of acetic acid (Fei et al, ). In addition, not only the lipid concentration but also lipid distribution was affected by different VFAs, as it has been demonstrated that increasing propionic and butyric acid could enhance odd‐chain FA production in several OY (Kolouchová et al, ; J. Liu et al, ; Park, Dulermo, Ledesma‐Amaro, & Nicaud, ).…”