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.

Highlights

• Slight variations in SCFA concentrations have a relevant effect on yeast lipid production

• High nitrogen availability is crucial to promote cell growth at very high SCFA concentrations

• C:N effect on cell growth and lipid production is specie-specific and may depend on yeast robustness

• Yeast strains have diverse SCFA preferences and differently metabolize these acids

• Struvite precipitation effectively removes nitrogen from real digestates increasing C:N

KEYWORDS:

• Cutaneotrichosporon curvatum
• Yarrowia lipolytica
• microbial oils
• carbon:nitrogen ratio
• short-chain fatty acids

Acknowledgments

The authors want to thank Paula Ochoa for assisting in the fermentation tests.

Disclosure statement

Authors do not have interests to declare

Authors contributions

Elia Tomás-Pejó, Conceptualization, Writing – Original Draft, Review & Editing, Supervision, Sergio Morales-Palomo Investigation, Writing – Review & Editing, Cristina González-Fernández Conceptualization, Writing – Review & Editing, Supervision

Data availability statement

The data that support the findings of this study are available from the corresponding author, ETP, upon reasonable request.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research has been supported by the project BIOMIO+H2 (PID2020-119403RBC21) funded by MCIN/AEI/10.13039/501100011033, OLEOFERM (EraBoBiotech; PCI2021-121936) funded by MCIN/AEI/10.13039/501100011033 and “European Union NextGenerationEU/PRTR”. The grants RYC2019-027773-I and PRE2018-086477 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future” are also acknowledged.