Oleaginous yeasts for biodiesel: Current and future trends in biology and production

Abstract

Production of biodiesel from edible plant oils is quickly expanding worldwide to fill a need for renewable, environmentally-friendly liquid transportation fuels. Due to concerns over use of edible commodities for fuels, production of biodiesel from non-edible oils including microbial oils is being developed. Microalgae biodiesel is approaching commercial viability, but has some inherent limitations such as requirements for sunlight. While yeast oils have been studied for decades, recent years have seen significant developments including discovery of new oleaginous yeast species and strains, greater understanding of the metabolic pathways that determine oleaginicity, optimization of cultivation processes for conversion of various types of waste plant biomass to oil using oleaginous yeasts, and development of strains with enhanced oil production. This review examines aspects of oleaginous yeasts not covered in depth in other recent reviews. Topics include the history of oleaginous yeast research, especially advances in the early 20th century; the phylogenetic diversity of oleaginous species, beyond the few species commonly studied; and physiological characteristics that should be considered when choosing yeast species and strains to be utilized for conversion of a given type of plant biomass to oleochemicals. Standardized terms are proposed for units that describe yeast cell mass and lipid production.

Recent trends in biodiesel production

“…Yeasts not only sustain the unique features of microalgae such as high oil accumulation of up to 70% dry wt., and that they can be genetically modified to enhance production (Liang and Jiang, 2013), but also compared to microalgae offer other advantageous features, i.e., potentially faster growth rates, higher density growth, less susceptibility to viral infection, and bacterial contamination (Sitepu et al, 2014). Among the yeast species investigated, Rhodotorula , Cryptococcus , Lipomyces Candida sp.…”

Metabolic Engineering for Advanced Biofuels Production and Recent Advances Toward Commercialization

“…[59,92] When two enzymes, ACC1 and DGA1, were overexpressed in Y. lipolytica, lipids amassed up to 62% of DCW. [93] In addition, expression of a stearoyl-CoA desaturase (scd), a positive regulator to increase fatty acid flux, resulted in a productivity of 22 kg/m 3 /day.…”

Identification and Characterization of Diacylglycerol Acyltransferase in Oleaginous Yeast <i>Rhodosporidium toruloides</i>

“…Biodiesel, esterified from vegetable oils or animal fats with lower alcohol by now, acts as an alternative of fossil fueland biodiesel production, which is commercially available in Europe, the United States and other countries (Li et al, 2008;Sitepu et al, 2014). The main drawback of this technology is that it conflicts with food resources.…”