Sustainable production of FAEE biodiesel using the oleaginous yeast Yarrowia lipolytica

Abstract

Fatty acid ethyl esters (FAEEs) are fatty acid‐derived molecules and serve as an important form of biodiesel. The oleaginous yeast Yarrowia lipolytica is considered an ideal host platform for the production of fatty acid‐derived products due to its excellent lipid accumulation capacity. In this proof‐of‐principle study, several metabolic engineering strategies were applied for the overproduction of FAEE biodiesel in Y. lipolytica . Here, chromosome‐based co‐overexpression of two heterologous genes, namely, PDC1 (encoding pyruvate decarboxylase) and ADH1 (encoding alcohol dehydrogenase) from Saccharomyces cerevisiae , and the endogenous GAPDH (encoding glyceraldehyde‐3‐phosphate dehydrogenase) gene of Y. lipolytica resulted in successful biosynthesis of ethanol at 70.8 mg/L in Y. lipolytica . The engineered Y. lipolytica strain expressing the ethanol synthetic pathway together with a heterologous wax ester synthase (MhWS) exhibited the highest FAEE titer of 360.8 mg/L, which is 3.8‐fold higher than that of the control strain when 2% exogenous ethanol was added to the culture medium of Y. lipolytica . Furthermore, a synthetic microbial consortium comprising an engineered Y. lipolytica strain that heterologously expressed MhWS and a S. cerevisiae strain that could provide ethanol as a substrate for the production of the final product in the final engineered Y. lipolytica strain was created in this study. Finally, this synthetic consortium produced FAEE biodiesel at a titer of 4.8 mg/L under the optimum coculture conditions.

Overexpression and repression of key rate‐limiting enzymes (acetyl CoA carboxylase and HMG reductase) to enhance fatty acid production from Rhodotorula mucilaginosa

“…[42]. It was observed that the presence of the high percentage of fatty acid (C16-C18 carbon atom in the chain) will seem to be ideal as feedstock for biodiesel [12,17,42]. Producing renewable and environmentally safe biofuel helps in the development of green sustainable energy alternatives [11].…”

“…This type of cheaper carbon source as a substrate for lipid production will help in reducing the overall cost of the production. The FAME, produced from oleaginous yeast, is useful as biodiesel feedstock [17].…”

Yarrowia lipolytica as an Oleaginous Platform for the Production of Value-Added Fatty Acid-Based Bioproducts

“…In this research, the titer of FAEE up to 82 mg/L was achieved by the supplementation of vegetable cooking oil (Ng et al, 2019). Meanwhile, Yu et al (2020) developed the synthetic co-culture system comprising the engineered S. cerevisiae and Y. lipolytica strain, which was able to produce FAEE at 4.8 mg/L. To overcome the limitation of oxidative stability in the traditional FAMEs, Markham and Alper (2018) first performed the production of C19 cyclopropanated fatty acids in the engineered Y. lipolytica strain, harboring the heterologous cyclopropane fatty acid synthase from E. coli.…”

“…Recently, by coculturing and engineered Y. lipolytica and S. cerevisiae strain, a synthetic microbial consortium was constructed to increase the titer of FAEE. In this research, the titer of FAEE biodiesel at 4.8 mg/L was reached by the synthetic microbial consortium under the optimum coculture conditions (Yu et al, 2020).…”

Engineering Oleaginous Yeast Rhodosporidium Toruloides for Overproduction of Fatty Acid Ethyl Esters

“…In the future, more ethanol biosynthetic pathway genes from different ethanologenic organisms need to be evaluated and introduced to our engineered R. toruloides strain to construct an endogenously ethanol-producing pathway. Recently, this proposed strategy was demonstrated to be feasible in the oleaginous yeast Y. lipolytica for the synthesis of FAEEs without the addition of ethanol, but the titer of produced FAEEs was quite low (0.3 mg/L) due to the limited supply of ethanol [28]. Thus, further efforts to increase the production of ethanol is required.…”