Engineering Yarrowia lipolytica for efficient γ-linolenic acid production

Abstract

γ-linolenic acid (GLA) has various well-documented beneficial physiological effects and high biological significance. Because the natural supply of GLA is insufficient, microbial GLA production is a promising method for pharmaceutical and nutraceutical purposes. To establish and develop a biotechnological process for GLA production by Yarrowia lipolytica, the codon-optimized △6-desaturase from Mortierella alpina was introduced into this yeast under the control of the strong hp4d promoter. A recombinant Y. lipolytica strain was constructed, which produced 4.6% GLA in total fatty acids. By using a temperature-shift strategy of cultivation, consisting in preliminary growth at 28 °C followed by 6-day culture at 20 °C, optimal levels of dry cell weight (DCW), lipid content and GLA concentration were obtained from the recombinant strain: 18.55 g/L, 1.16 g/L and 71.6 mg/L, respectively. These DCW, lipid and GLA values were respectively 25.7%, 19.6% and 60.9% higher than those obtained in the control cultivation experiment at the standard constant temperature of 28 °C. This work demonstrates the excellent capacity of Y. lipolytica for GLA production, by combining metabolic engineering with a temperature-shift strategy.

Engineering Yarrowia lipolytica for arachidonic acid production through rapid assembly of metabolic pathway

“…Whereas, using C18:2 as a substrate, C18:3 was synthesized in the engineered Y. lipolytica strain via the novel ARA biosynthesis pathway. For YL 6-1 strain, the C18:3 content reached to 2.8% of total fatty acids at 72 h. Recently, we have constructed an engineered Y. lipolytica capable of producing C18:3 (6% of TFA) under the optimized fermentation process [39]. Using C18:3 as a substrate, this engineered strain was thus able to produce C20:3 via the novel ARA biosynthesis pathway.…”

Soluble Sugar and Lipid Readjustments in the Yarrowia lipolytica Yeast at Various Temperatures and pH

“…In [31], a three-fold increase in α-linolenic acid production under low-temperature cultivation in the Y. lipolytica line with transformed ∆12-15 desaturase (RkD12-15) was shown. So far, some studies have used low temperature cultivation in some yeast species, namely Y. lipolytica and Mortierella alpina, to produce polyunsaturated fatty acids [32,33]. When cultivated at 28 • C for 24 h followed by 20 • C, Y. lipolytica could increase γ-linolenic acid production by 60.9% [32].…”

“…So far, some studies have used low temperature cultivation in some yeast species, namely Y. lipolytica and Mortierella alpina, to produce polyunsaturated fatty acids [32,33]. When cultivated at 28 • C for 24 h followed by 20 • C, Y. lipolytica could increase γ-linolenic acid production by 60.9% [32]. The elevating temperature increased the long-chain fatty acid levels in Y. lipolytica yeast.…”

Metabolic Engineering of Oleaginous Yeasts for Production of Fuels and Chemicals

“…In the engineered strain, a high level of ARA production (0.4% of total FAs) was achieved. Similarly, the same group also engineered Y. lipolytica for the production of γ-linolenic acid (GLA) ( Sun et al, 2017 ). An optimized GLA production at 71.6 mg/L was obtained by applying a novel temperature-shift strategy.…”

“…Among oleaginous yeasts, Yarrowia lipolytica is the most-well studied one. Thanks to the availability of genetic tools ( Madzak, 2015 ; Schwartz et al, 2015 ), Y. lipolytica has been used for a variety of biotechnological applications, including the production of PUFAs ( Xue et al, 2013 ; Liu et al, 2017 ; Sun et al, 2017 ), citric acid ( Förster et al, 2007 ; Moeller et al, 2013 ; Tan et al, 2016 ), and alkanes ( Xu et al, 2016 ). Moreover, Y. lipolytica has also been shown to be rather robust and able to grow on a variety of substrates ( Papanikolaou et al, 2002 ; Ledesma-Amaro and Nicaud, 2016b ; Mirończuk et al, 2016 ).…”