Efficient Conversion of Fructose-Based Biomass into Lipids with Trichosporon fermentans Under Phosphate-Limited Conditions

Abstract

Limiting nitrogen supply has been routinely used as the master regulator to direct lipid biosynthesis. However, this strategy does not work with nitrogen-rich substrates, such as Jerusalem artichoke (JA), a fructose-based biomass, while it is difficult to obtain a high carbon-to-nitrogen (C/N) molar ratio. In this study, an alternative strategy to promote lipid accumulation by the oleaginous yeast Trichosporon fermentans CICC 1368 was developed by limiting phosphorous supply, and this strategy was implemented with JA hydrolysate as substrate. We showed that lipid accumulation was directly correlated with the C/P ratio of the culture media for T. fermentans. The time course of cell growth and lipid production was analyzed in a media with an initial C/P ratio of 6342, and the cellular lipid content could reach up to 48.5% of dry biomass. Moreover, JA hydrolysates were used as substrate for microbial lipid accumulation, under high C/P molar ratio condition, lipid yield, lipid content, and lipid coefficient increased by 10, 30, and 34%, respectively. It showed that by limiting phosphorus, the conversion of sugar into lipids can be improved effectively. Limiting phosphorus provides a promising solution to the problem of microbial lipid production with nitrogen-rich natural materials.

Systems analysis of phosphate-limitation-induced lipid accumulation by the oleaginous yeast Rhodosporidium toruloides

“…These results showed that cells had lipids less that 10% without nutrient limitation, while cells accumulated lipids to over 40% under Pi-limitation. Our data were in agreement with a number of earlier observations that Pi-limitation facilitated lipid production by oleaginous fungi [ 6 , 8 – 10 ]. More interestingly, the much greater increase in lipid yield than in cell mass yield suggested that cells used glucose more efficiently for lipid biosynthesis under Pi-limitation.…”

“…As Pi can be readily removed from aqueous streams at large scale, it is appealing to use Pi-limitation as a convenient strategy to explore nitrogen-rich raw materials for lipid production. Indeed, high cellular lipid contents were documented by different oleaginous hosts under Pi-limitation [ 8 – 10 ], even in the presence of excess nitrogenous nutrients [ 7 , 11 ]. Nonetheless, the molecular basis of cellular responses to Pi-limitation and concurrent lipid accumulation by oleaginous species remains elusive.…”

Deproteinated Potato Wastewater as a Sustainable Nitrogen Source in Trichosporon domesticum Yeast Lipids Biosynthesis—a Concept of Valorization of Wastewater from Starch Industry

“…Oleic acid (C18:1) was only be detected at low levels in sugar-based media and was not detected after incubation with glycerol (Shen et al 2015). Three major fatty acids of the same strain of oils obtained from medium with fructose were palmitic acid (16:0), stearic acid (18:0), and oleic acid (18:1), and these three fatty acids accounted for over 95% of the total fatty acids (Bao et al 2018).…”

“…The enzyme has an optimum pH in the range of 8.0-8.5 and an optimum temperature of 32°C and shows no metal dependence on the chloride salts of sodium, potassium, magnesium, or ferrum (Goldson-Barnaby and Scaman 2013). Trichosporon fermentans can produce lipids with various cheap substrates such as rice straw hydrolysates (Huang et al 2009) and molasses (Zhu et al 2008;Shen et al 2015) or nitrogen-rich Jerusalem artichoke hydrolysates (Bao et al 2018). T. cutaneum produces biomass rich in oils after incubation on steam-exploded and three-stage enzymatic hydrolysis corn stover.…”

Evaluation of sugarcane leaves as a substrate for production of palmitoleic acid using Cyberlindnera subsufficiens NG8.2

“…Soluble phosphate can be removed by precipitation with metal ions, such as Ca 2+ and Mg 2+ (Kolouchová et al 2016). Treatment with Ca(OH)2 (over-liming) is a popular method for removing soluble phosphate by precipitating it as Ca3(PO4)2 (Xia et al 2016;Bao et al 2018). This approach has been used to remove phosphate from several lignocellulosic hydrolysates (Wu et al 2010;Bao et al 2018;Zhou et al 2019).…”