Transcriptomic Analyses during the Transition from Biomass Production to Lipid Accumulation in the Oleaginous Yeast Yarrowia lipolytica

ABSTRACTIn the oleaginous yeastYarrowia lipolytica,de novolipid synthesis and accumulation are induced under conditions of nitrogen limitation (or a high carbon-to-nitrogen ratio). The regulatory pathway responsible for this induction has not been identified. Here we report that the SNF1 pathway plays a key role in the transition from the growth phase to the oleaginous phase inY. lipolytica. Strains with aY. lipolyticasnf1(Ylsnf1) deletion accumulated fatty acids constitutively at levels up to 2.6-fold higher than those of the wild type. When introduced into aY. lipolyticastrain engineered to produce omega-3 eicosapentaenoic acid (EPA),Ylsnf1deletion led to a 52% increase in EPA titers (7.6% of dry cell weight) over the control. Other components of theY. lipolyticaSNF1 pathway were also identified, and their function in limiting fatty acid accumulation is suggested by gene deletion analyses. Deletion of the gene encoding YlSnf4, YlGal83, or YlSak1 significantly increased lipid accumulation in both growth and oleaginous phases compared to the wild type. Furthermore, microarray and quantitative reverse transcription-PCR (qRT-PCR) analyses of theYlsnf1mutant identified significantly differentially expressed genes duringde novolipid synthesis and accumulation inY. lipolytica. Gene ontology analysis found that these genes were highly enriched with genes involved in lipid metabolism. This work presents a new role for Snf1/AMP-activated protein kinase (AMPK) pathways in lipid accumulation in this oleaginous yeast.

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Stable isotope and chemical inhibition analyses suggested the existence of a non-mevalonate-like pathway in the yeast Yarrowia lipolytica

Scientific Reports ◽

10.1038/s41598-021-85170-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sivamoke Dissook ◽

Tomohisa Kuzuyama ◽

Yuri Nishimoto ◽

Shigeru Kitani ◽

Sastia Putri ◽

...

Keyword(s):

Yarrowia Lipolytica ◽

Oleaginous Yeast ◽

Isoprenoid Biosynthesis ◽

Mep Pathway ◽

Authentic Standard ◽

Chemical Inhibition ◽

Chromatographic Peaks ◽

Methyl Erythritol Phosphate ◽

Limiting Condition ◽

Yeast Yarrowia Lipolytica

AbstractMethyl erythritol phosphate (MEP) is the metabolite found in the MEP pathway for isoprenoid biosynthesis, which is known to be utilized by plants, algae, and bacteria. In this study, an unprecedented observation was found in the oleaginous yeast Yarrowia lipolytica, in which one of the chromatographic peaks was annotated as MEP when cultivated in the nitrogen limiting condition. This finding raised an interesting hypothesis of whether Y. lipolytica utilizes the MEP pathway for isoprenoid biosynthesis or not, because there is no report of yeast harboring the MEP pathway. Three independent approaches were used to investigate the existence of the MEP pathway in Y. lipolytica; the spiking of the authentic standard, the MEP pathway inhibitor, and the 13C labeling incorporation analysis. The study suggested that the mevalonate and MEP pathways co-exist in Y. lipolytica and the nitrogen limiting condition triggers the utilization of the MEP pathway in Y. lipolytica.

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