An Insight into Storage Lipid Synthesis by Yarrowia lipolytica Yeast Relating to Lipid and Sugar Substrates Metabolism

Abstract

Single cell oil (SCO) is the lipid accumulated in the cells of oleaginous microorganisms. Cellular lipids can be synthesized in two different pathways: de novo by metabolizing hydrophilic substrates and ex novo by fermenting hydrophobic substrates. The aim of the study was to evaluate the effect of carbon source (glucose and olive oil) in the culture medium on the course of microbial oil accumulation in Y. lipolytica cells. The level of selected gene expression by real time quantitative PCR method was investigated. The significant increase in expression of the POX2 gene encoding acyl-CoA oxidase II, which preferentially oxidizes long-chain acyl-CoAs formed from substrate fatty acids incorporated inside the microbial cell, was observed in medium with olive oil in relation to glucose containing medium. Noteworthily, the presence of lipid carbon substrate did not inhibit the level of ACL gene transcription coding for ATP-citrate lyase, the key enzyme of the lipid de novo accumulation process. The present study indicated that de novo lipid biosynthesis could occur despite the presence of fatty acids in the medium, and the synthesis of storage lipids in the presence of lipid carbon substrates could be carried out with the use of both pathways (de novo and ex novo).

Studies on Upgradation of Waste Fish Oil to Lipid-Rich Yeast Biomass in Yarrowia lipolytica Batch Cultures

“…De novo accumulation of cellular lipids involves citric and isocitric acids accumulation as the tricarboxylic acids cycle is blocked. Meanwhile, Fabiszewska et al [ 21 ] indicated that de novo lipid biosynthesis could occur despite the presence of fatty acids in the medium, and the synthesis of storage lipids in the presence of lipid carbon sources could be carried out with the use of both pathways in Y. lipolytica cells (de novo and ex novo). In the present study, the low pH of supernatant and the composition of microbial oil might have acknowledged the hypothesis.…”

Use of Non-Conventional Yeast Yarrowia lipolytica in Treatment or Upgradation of Hydrophobic Industry Wastes

“…γ-decalactone [19], carotenoidse.g. β-carotene [20], organic acids-α-ketoglutaric, succinic, citric and pyruvic acids [21], lipases-enzymes used in food production, for water purification or as an ingredient in detergents [22], SCP (Single Cell Protein)-proteins of microbiological origin that can be used as feed additives [23], SCO (Single Cell Oil)-microbiological oil which is a source of essential unsaturated fatty acids (EFA) with valuable properties for both humans and farm animals [5,24].…”

Waste fish oil as an alternative carbon source in microbial oil production by Yarrowia lipolytica yeast

“…In the studies described in this paper, lipid substrates were used in medium, so the ex novo pathway, which is independent of nitrogen limitation, was expected to take part in microbial oil synthesis. Meanwhile, the use of a high ratio of carbon to nitrogen source content in the culture medium turned out to be equally beneficial and reasonable as it was claimed for de novo route, what was also hypothesized by Fabiszewska et al (2019). Source/ ród o: own study based/opracowanie w asne.…”