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Low-cost lipid production by an oleaginous yeast cultured in non-sterile conditions using model waste resources.

Santamauro F, Whiffin FM, Scott RJ, Chuck CJ - Biotechnol Biofuels (2014)

Bottom Line: This approach resulted in yields of up to 40% lipid, which compares favourably with other oleaginous microbes.We also demonstrate that M. pulcherrima metabolises glycerol and a diverse range of other sugars, suggesting that heterogeneous biomass could provide a suitable carbon source.M. pulcherrima also grows well in a minimal media containing no yeast extract.

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Affiliation: Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK. R.J.Scott@bath.ac.uk.

ABSTRACT

Background: The yeast Metschnikowia pulcherrima, previously utilised as a biological control agent, was evaluated for its potential to produce lipids for biofuel production.

Results: Cultivation in low cost non-sterile conditions was achieved by exploiting its ability to grow at low temperature and pH and to produce natural antimicrobial compounds. Although not previously classified as oleaginous, a combination of low temperature and restricted nutrient availability triggered high levels of oil production in M. pulcherrima cultures. This regime was designed to trigger the sporulation process but prevent its completion to allow the accumulation of a subset of a normally transitional, but oil-rich, 'pulcherrima' cell type. This approach resulted in yields of up to 40% lipid, which compares favourably with other oleaginous microbes. We also demonstrate that M. pulcherrima metabolises glycerol and a diverse range of other sugars, suggesting that heterogeneous biomass could provide a suitable carbon source. M. pulcherrima also grows well in a minimal media containing no yeast extract. Finally, we demonstrate the potential of the yeast to produce lipids inexpensively on an industrial scale by culturing the yeast in a 500 L, open air, tank reactor without any significant contamination.

Conclusions: The production of antimicrobial compounds coupled to efficient growth at low temperature and pH enables culture of this oleaginous yeast in inexpensive, non-sterile conditions providing a potential route to economic biofuel production.

No MeSH data available.


Related in: MedlinePlus

Nutrient requirements for M. pulcherrima cultivation on glycerol. a) Nitrogen source, b) sulphur content and c) demonstrates the removal of micronutrients.
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Figure 4: Nutrient requirements for M. pulcherrima cultivation on glycerol. a) Nitrogen source, b) sulphur content and c) demonstrates the removal of micronutrients.

Mentions: A key issue when using waste feedstocks is the potential heterogeneity of supply, which demands that the cultured organism possesses a degree of flexibility in its nutrient and environmental requirements. To assess M. pulcherrima for its potential for robust waste feedstock utilisation we measured the impact of different nutrient sources on growth dynamics. Three alternative nitrogen sources (NH4Cl, NH4NO3 and Ca(NO3)2) were evaluated by replacing (NH4)2SO4 in the standard M. pulcherrima (SMP) containing 10% w/v glycerol. The total nitrogen concentration was kept constant when using the different nitrogen sources. Biomass productivity was greatest using ammonium salts compared to nitrates (Figure 4a), with NH4Cl supporting a growth rate comparable to (NH4)2SO4. In contrast, the performance of NH4NO3 and Ca(NO3)2 was below 3 g/L indicating that these compounds are not suitable nitrogen sources for M. pulcherrima.


Low-cost lipid production by an oleaginous yeast cultured in non-sterile conditions using model waste resources.

Santamauro F, Whiffin FM, Scott RJ, Chuck CJ - Biotechnol Biofuels (2014)

Nutrient requirements for M. pulcherrima cultivation on glycerol. a) Nitrogen source, b) sulphur content and c) demonstrates the removal of micronutrients.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016040&req=5

Figure 4: Nutrient requirements for M. pulcherrima cultivation on glycerol. a) Nitrogen source, b) sulphur content and c) demonstrates the removal of micronutrients.
Mentions: A key issue when using waste feedstocks is the potential heterogeneity of supply, which demands that the cultured organism possesses a degree of flexibility in its nutrient and environmental requirements. To assess M. pulcherrima for its potential for robust waste feedstock utilisation we measured the impact of different nutrient sources on growth dynamics. Three alternative nitrogen sources (NH4Cl, NH4NO3 and Ca(NO3)2) were evaluated by replacing (NH4)2SO4 in the standard M. pulcherrima (SMP) containing 10% w/v glycerol. The total nitrogen concentration was kept constant when using the different nitrogen sources. Biomass productivity was greatest using ammonium salts compared to nitrates (Figure 4a), with NH4Cl supporting a growth rate comparable to (NH4)2SO4. In contrast, the performance of NH4NO3 and Ca(NO3)2 was below 3 g/L indicating that these compounds are not suitable nitrogen sources for M. pulcherrima.

Bottom Line: This approach resulted in yields of up to 40% lipid, which compares favourably with other oleaginous microbes.We also demonstrate that M. pulcherrima metabolises glycerol and a diverse range of other sugars, suggesting that heterogeneous biomass could provide a suitable carbon source.M. pulcherrima also grows well in a minimal media containing no yeast extract.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK. R.J.Scott@bath.ac.uk.

ABSTRACT

Background: The yeast Metschnikowia pulcherrima, previously utilised as a biological control agent, was evaluated for its potential to produce lipids for biofuel production.

Results: Cultivation in low cost non-sterile conditions was achieved by exploiting its ability to grow at low temperature and pH and to produce natural antimicrobial compounds. Although not previously classified as oleaginous, a combination of low temperature and restricted nutrient availability triggered high levels of oil production in M. pulcherrima cultures. This regime was designed to trigger the sporulation process but prevent its completion to allow the accumulation of a subset of a normally transitional, but oil-rich, 'pulcherrima' cell type. This approach resulted in yields of up to 40% lipid, which compares favourably with other oleaginous microbes. We also demonstrate that M. pulcherrima metabolises glycerol and a diverse range of other sugars, suggesting that heterogeneous biomass could provide a suitable carbon source. M. pulcherrima also grows well in a minimal media containing no yeast extract. Finally, we demonstrate the potential of the yeast to produce lipids inexpensively on an industrial scale by culturing the yeast in a 500 L, open air, tank reactor without any significant contamination.

Conclusions: The production of antimicrobial compounds coupled to efficient growth at low temperature and pH enables culture of this oleaginous yeast in inexpensive, non-sterile conditions providing a potential route to economic biofuel production.

No MeSH data available.


Related in: MedlinePlus