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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.

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

Total biomass and lipid produced (shaded area) for glycerol and a model for depolymerised lignocellulose in optimised media, and consumption of sugars and glycerol over the culture period. a) Total biomass and lipid produced and model for depolymerised lignocelluloses. The model contained 7.5 g, arabinose, 7.5 g xylose, 7.5 g glucose and 7.5 g cellobiose as the carbon source. b) Consumption of sugars. c) The consumption of glycerol over the culture period.
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Figure 7: Total biomass and lipid produced (shaded area) for glycerol and a model for depolymerised lignocellulose in optimised media, and consumption of sugars and glycerol over the culture period. a) Total biomass and lipid produced and model for depolymerised lignocelluloses. The model contained 7.5 g, arabinose, 7.5 g xylose, 7.5 g glucose and 7.5 g cellobiose as the carbon source. b) Consumption of sugars. c) The consumption of glycerol over the culture period.

Mentions: As the main products of the depolymerisation of lignocellulose are glucose, arabinose, xylose and cellobiose, M. pulcherrima was cultured on a mixture of these sugars as a model waste resource and the biomass and lipid productivity established (Figure 7). M. pulcherrima produced amounts of biomass and lipid on this feedstock similar to levels achieved on glycerol. Significantly, with the exception of xylose, all four sugars of the model feedstock were starting to be catabolised by M. pulcherrima within the first 24 hours. Xylose consumption commenced within 48 hours. By 72 hours the culture had entered the stationary phase (data not shown), and the consumption of glucose, arabinose and cellobiose practically halted. Interestingly, xylose was continually consumed until exhausted after 12 days. It is possible that M. pulcherrima catabolises xylose directly, or that xylose is converted into an unknown secondary product. On exhaustion of the xylose, M. pulcherrima resumed using other sugars in the broth. After 15 days, both the glycerol and model lignocellulose cultures, had consumed nearly 20 g⋅L-1 of sugar, which was two thirds of the original starting culture.


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)

Total biomass and lipid produced (shaded area) for glycerol and a model for depolymerised lignocellulose in optimised media, and consumption of sugars and glycerol over the culture period. a) Total biomass and lipid produced and model for depolymerised lignocelluloses. The model contained 7.5 g, arabinose, 7.5 g xylose, 7.5 g glucose and 7.5 g cellobiose as the carbon source. b) Consumption of sugars. c) The consumption of glycerol over the culture period.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 7: Total biomass and lipid produced (shaded area) for glycerol and a model for depolymerised lignocellulose in optimised media, and consumption of sugars and glycerol over the culture period. a) Total biomass and lipid produced and model for depolymerised lignocelluloses. The model contained 7.5 g, arabinose, 7.5 g xylose, 7.5 g glucose and 7.5 g cellobiose as the carbon source. b) Consumption of sugars. c) The consumption of glycerol over the culture period.
Mentions: As the main products of the depolymerisation of lignocellulose are glucose, arabinose, xylose and cellobiose, M. pulcherrima was cultured on a mixture of these sugars as a model waste resource and the biomass and lipid productivity established (Figure 7). M. pulcherrima produced amounts of biomass and lipid on this feedstock similar to levels achieved on glycerol. Significantly, with the exception of xylose, all four sugars of the model feedstock were starting to be catabolised by M. pulcherrima within the first 24 hours. Xylose consumption commenced within 48 hours. By 72 hours the culture had entered the stationary phase (data not shown), and the consumption of glucose, arabinose and cellobiose practically halted. Interestingly, xylose was continually consumed until exhausted after 12 days. It is possible that M. pulcherrima catabolises xylose directly, or that xylose is converted into an unknown secondary product. On exhaustion of the xylose, M. pulcherrima resumed using other sugars in the broth. After 15 days, both the glycerol and model lignocellulose cultures, had consumed nearly 20 g⋅L-1 of sugar, which was two thirds of the original starting culture.

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