High-oleate yeast oil without polyunsaturated fatty acids

Abstract

BackgroundOleate-enriched triacylglycerides are well-suited for lubricant applications that require high oxidative stability. Fatty acid carbon chain length and degree of desaturation are key determinants of triacylglyceride properties and the ability to manipulate fatty acid composition in living organisms is critical to developing a source of bio-based oil tailored to meet specific application requirements.ResultsWe sought to engineer the oleaginous yeast Yarrowia lipolytica for production of high-oleate triacylglyceride oil. We studied the effect of deletions and overexpressions in the fatty acid and triacylglyceride synthesis pathways to identify modifications that increase oleate levels. Oleic acid accumulation in triacylglycerides was promoted by exchanging the native ∆9 fatty acid desaturase and glycerol-3-phosphate acyltransferase with heterologous enzymes, as well as deletion of the Δ12 fatty acid desaturase and expression of a fatty acid elongase. By combining these engineering steps, we eliminated polyunsaturated fatty acids and created a Y. lipolytica strain that accumulates triglycerides with > 90% oleate content.ConclusionsHigh-oleate content and lack of polyunsaturates distinguish this triacylglyceride oil from plant and algal derived oils. Its composition renders the oil suitable for applications that require high oxidative stability and further demonstrates the potential of Y. lipolytica as a producer of tailored lipid profiles.Electronic supplementary materialThe online version of this article (10.1186/s13068-018-1131-y) contains supplementary material, which is available to authorized users.

Homology‐independent genome integration enables rapid library construction for enzyme expression and pathway optimization in Yarrowia lipolytica

“…Similar to previous studies (Friedlander et al, ; Tsakraklides et al, ; Xue et al, ), the above result demonstrated the efficiency of one‐step library construction using homology‐independent integration, but its potential for multivariate modular library construction for metabolic pathway optimization has not been explored. Therefore, as a proof of concept, the β‐carotene synthetic pathway was optimized through homology‐independent modular combinatorial integration.…”

“…Instead of improving the HR efficiency, an alternative approach is to use the inherent NHEJ pathway to integrate DNA into Y. lipolytica . Although NHEJ‐mediated genome integration has been reported for strain construction and enzyme activity screening (Friedlander et al, ; Tsakraklides et al, ; Xue et al, ; Ye, Sharpe, & Zhu, ), it has only been used to integrate single DNA fragments (one gene or several genes in one vector). The potential for simultaneously integrating multiple DNA fragments for modular library construction has not been explored.…”

Isolation, identification and screening of yeasts towards their ability to assimilate biodiesel‐derived crude glycerol: microbial production of polyols, endopolysaccharides and lipid

“…Eventually, a SCO presenting indeed very high concentrations of the FA C18:1 ( ω ‐9) (i.e. concentrations >70% w/w of total FAs) and presenting excellent composition as regards its potential transformation into second generation biodiesel or as a fatty material amenable for its employment for various lubricant applications (Papanikolaou and Aggelis ; Patel et al ; Uprety et al ; Athenaki et al ; Carsanba et al ; Tsakraklides et al ) was synthesized.…”

“…The highest SCO production in the current investigation was reported by R. glutinis NRRL YB‐252 (L max = 7·2 g l −1 , Y L/X = 38·2% w/w), that are values quite interesting and comparable to several ones reported in the literature concerning growth of ‘red’ yeasts (genera Rhodosporidium or Rhodotorula ) on various low‐cost hydrophilic carbon sources (Saenge et al ; Uçkun Kiran et al ; Patel et al , , , ; Uprety et al , b). Lipid produced by R. glutinis NRRL YB‐252 cultivated in high Gly 0 concentrations presented high quantities of oleic acid (>70% w/w), suggesting the use of Gly as substrate in order for lipid presenting excellent composition as regards its potential transformation into second generation biodiesel or its utilization as starting fatty material amenable for various lubricant applications (Uprety et al ; Tsakraklides et al ) to be created. Analysis of SCO produced for all yeast strains indicated the presence in variable quantities of the FAs oleic, palmitic, stearic and linoleic.…”

“…Moreover, SCO presenting high concentrations of the FA C18:1 ( ω ‐9), a perfect FA composition in order second generation biodiesel to be created, was synthesized in significant quantities by the yeast R. glutinis . Besides biodiesel synthesis, lipids presenting high oleic acid concentrations can present interest in various lubricant applications (Tsakraklides et al ). In addition, mannitol that is another compound has been synthesized in non‐negligible concentrations in the current investigation as the principal product of Gly fermentation by Y. lipolytica strains, presents interest as sweetener and food additive (the cost of mannitol is ≈3·5 US $ per kg).…”