Enhanced lipid production and nutrient utilization of food waste hydrolysate by mixed culture of oleaginous yeast Rhodosporidium toruloides and oleaginous microalgae Chlorella vulgaris

Abstract Background Crude glycerol as a promising feedstock for microbial lipid production contains several impurities that make it toxic stress inducer at high amount. Under stress conditions, microorganisms can accumulate l-proline as a safeguard. Herein, l-proline was assessed as an anti-stress agent in crude glycerol media. Results Crude glycerol was converted to microbial lipids by the oleaginous yeast Rhodosporidium toruloides CGMCC 2.1389 in a two-staged culture mode. The media was supplied with exogenous l-proline to improve lipid production efficiency in high crude glycerol stress. An optimal amount of 0.5 g/L l-proline increased lipid titer and lipid yield by 34% and 28%, respectively. The lipid titer of 12.2 g/L and lipid content of 64.5% with a highest lipid yield of 0.26 g/g were achieved with l-proline addition, which were far higher than those of the control, i.e., lipid titer of 9.1 g/L, lipid content of 58% and lipid yield of 0.21 g/g. Similarly, l-proline also improved cell growth and glycerol consumption. Moreover, fatty acid compositional profiles of the lipid products was found suitable as a potential feedstock for biodiesel production. Conclusion Our study suggested that exogenous l-proline improved cell growth and lipid production on crude glycerol by R. toruloides. The fact that higher lipid yield as well as glycerol consumption indicated that l-proline might act as a potential anti-stress agent for the oleaginous yeast strain.

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Redox governed electro-fermentation improves lipid production by the oleaginous yeast Rhodosporidium toruloides

Bioresource Technology ◽

10.1016/j.biortech.2019.122122 ◽

2019 ◽

Vol 294 ◽

pp. 122122 ◽

Cited By ~ 2

Author(s):

Philipp Arbter ◽

Aakanksha Sinha ◽

Julie Troesch ◽

Tyll Utesch ◽

An-Ping Zeng

Keyword(s):

Oleaginous Yeast ◽

Lipid Production ◽

Rhodosporidium Toruloides

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Partial purification and properties of pyruvate kinase and its regulatory role during lipid accumulation by the oleaginous yeast Rhodosporidium toruloides CBS 14

Canadian Journal of Microbiology ◽

10.1139/m85-089 ◽

1985 ◽

Vol 31 (5) ◽

pp. 479-484 ◽

Cited By ~ 11

Author(s):

Christopher Thomas Evans ◽

Colin Ratledge

Keyword(s):

Pyruvate Kinase ◽

Oleaginous Yeast ◽

Lipid Production ◽

Energy Charge ◽

Rhodosporidium Toruloides ◽

Regulatory Role ◽

Relative Mass ◽

Partial Purification ◽

Wide Range ◽

Fructose 1,6 Bisphosphate

Pyruvate kinase from the oleaginous yeast Rhodosporidium toruloides CBS 14 was partially purified and its properties investigated to determine its role during lipid production by this yeast. The enzyme (relative mass (Mr) = 190 000) showed a pH optimum of 8.0 and apparent Km values for K+, phosphoenolpyruvate (PEP), and ADP of 1.6 mM, 571 μM, and 120 μM, respectively. Enzyme activity was inhibited by citrate, isocitrate, ATP, GTP, and CTP and activated by fructose 1,6-bisphosphate, L-glutamate, and [Formula: see text] ions. Inhibition by citrate and ATP were both competitive with PEP with the Ki(citrate) = 340 μM and Ki(ATP) = 303 μM. The effect of ATP and cellular energy charge were critically dependent on the concentration of ADP present in the enzyme assay. Both L-glutamate and fructose 1,6-bisphosphate increased the affinity of the enzyme for both PEP and ADP and so were significant activators at nonsaturating substrate concentrations. [Formula: see text] ions increased the affinity of the enzyme for PEP, but not ADP. The modulation of pyruvate kinase activity by such a wide range of effectors is indicative of a major regulatory role in controlling the flux of carbon, through glycolysis, into lipid-synthesizing systems.

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Production of galactitol from galactose by the oleaginous yeast Rhodosporidium toruloides IFO0880

Biotechnology for Biofuels ◽

10.1186/s13068-019-1586-5 ◽

2019 ◽

Vol 12 (1) ◽

Cited By ~ 5

Author(s):

Sujit Sadashiv Jagtap ◽

Ashwini Ashok Bedekar ◽

Jing-Jing Liu ◽

Yong-Su Jin ◽

Christopher V. Rao

Keyword(s):

Oleaginous Yeast ◽

Lipid Production ◽

Value Added ◽

Building Blocks ◽

Rhodosporidium Toruloides ◽

Sugar Alcohols ◽

Galactose Metabolism ◽

Alcohol Production ◽

Wide Range ◽

Multiple Value

Abstract Background Sugar alcohols are commonly used as low-calorie sweeteners and can serve as potential building blocks for bio-based chemicals. Previous work has shown that the oleaginous yeast Rhodosporidium toruloides IFO0880 can natively produce arabitol from xylose at relatively high titers, suggesting that it may be a useful host for sugar alcohol production. In this work, we explored whether R. toruloides can produce additional sugar alcohols. Results Rhodosporidium toruloides is able to produce galactitol from galactose. During growth in nitrogen-rich medium, R. toruloides produced 3.2 ± 0.6 g/L, and 8.4 ± 0.8 g/L galactitol from 20 to 40 g/L galactose, respectively. In addition, R. toruloides was able to produce galactitol from galactose at reduced titers during growth in nitrogen-poor medium, which also induces lipid production. These results suggest that R. toruloides can potentially be used for the co-production of lipids and galactitol from galactose. We further characterized the mechanism for galactitol production, including identifying and biochemically characterizing the critical aldose reductase. Intracellular metabolite analysis was also performed to further understand galactose metabolism. Conclusions Rhodosporidium toruloides has traditionally been used for the production of lipids and lipid-based chemicals. Our work demonstrates that R. toruloides can also produce galactitol, which can be used to produce polymers with applications in medicine and as a precursor for anti-cancer drugs. Collectively, our results further establish that R. toruloides can produce multiple value-added chemicals from a wide range of sugars.

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