Cutaneotrichosporon curvatum and Yarrowia lipolytica as key players for green chemistry: efficient oil producers from food waste via the carboxylate platform

Abstract

Cutaneotrichosporon curvatum and Yarrowia lipolytica can accumulate microbial oils using short-chain fatty acids (SCFA) as carbon sources. SCFAs-rich media often contain significant amounts of nitrogen that prevent high carbon:nitrogen (C:N) ratios necessary to boost lipid production. This work assessed the intrinsic ability of C. curvatum and Y. lipolytica to produce high amounts of microbial oils from these unusual carbon sources. Results demonstrated that minor differences in SCFA concentration (only 2 g/L) had a significant effect on yeast growth and lipid production. A C:N of 80 promoted yeast growth at all SCFA concentrations and favored SCFA consumption at 19 g/L SCFAs. The different SCFA uptake preferences in C. curvatum and Y. lipolytica highlighted the importance of considering the SCFA profile to select a suitable yeast strain for microbial oils production. At the most challenging SCFA concentration (19 g/L), 57.2% ±1.6% (w/w) and 78.4 ± 0.6% (w/w) lipid content were obtained in C. curvatum and Y. lipolytica , respectively. These values are among the highest reported for wild-type strains. To circumvent the challenges associated with media with high nitrogen content, this report also proved struvite precipitation as an effective method for increasing lipid production (from 17.9 ± 3.9% (w/w) to 41.9 ± 2.6% (w/w)) after nitrogen removal in food waste-derived media.

High-throughput screening of non-conventional yeasts for conversion of organic waste to microbial oils via carboxylate platform

“…In comparison, only a few yeast species have been identified for their ability to utilize SCFAs: Y. lipolytica, Cutaneotrichosporon oleaginosum, Cutaneotrichosporon curvatum, Naganishia albida, Trichosporon cutaneum, Saccharomyces cerevisiae, Rhodotorula toruloides, Rhodotorula glutinis, Apiotrichum brassicae and Pichia kudriavzevii 2 , 12 , 13 , 16 – 21 . In particular, strains such as Y. lipolytica ACA DC 50 109, Y. lipolytica CICC 31,596, C. curvatum NRRL Y-1511, and C. curvatum ATCC 20,509 have a considerable ability to utilize SCFAs and accumulate lipids 22 – 24 . The strains Y. lipolytica ACA DC 50 109 and C. curvatum NRRL Y-1511 have been shown to accumulate up to 78% w/w and 57% w/w lipids, respectively, when cultivated on SCFAs at concentrations of up to 19 g/L and optimised carbon to nitrogen (C/N) ratio 24 .…”

“…In particular, strains such as Y. lipolytica ACA DC 50 109, Y. lipolytica CICC 31,596, C. curvatum NRRL Y-1511, and C. curvatum ATCC 20,509 have a considerable ability to utilize SCFAs and accumulate lipids 22 – 24 . The strains Y. lipolytica ACA DC 50 109 and C. curvatum NRRL Y-1511 have been shown to accumulate up to 78% w/w and 57% w/w lipids, respectively, when cultivated on SCFAs at concentrations of up to 19 g/L and optimised carbon to nitrogen (C/N) ratio 24 . Furthermore, strain C. curvatum ATCC 20,509 has been reported to accumulate 65% w/w lipids when cultivated with 40 g/L of acetic acid and up to 57% w/w when cultivated on a mixture of SCFAs at a concentration of 30 g/L 22 , 25 , 26 .…”