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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

Biomass productivity of M. pulcherrima on a range of simple sugars. Optical density (O.D.) of the culture after 15 days. GLU, glucose; XYL, xylose; GLY, glycerol; ARA, arabinose; CELL, cellobiose; LAC, lactose; SUC, sucrose.
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Figure 6: Biomass productivity of M. pulcherrima on a range of simple sugars. Optical density (O.D.) of the culture after 15 days. GLU, glucose; XYL, xylose; GLY, glycerol; ARA, arabinose; CELL, cellobiose; LAC, lactose; SUC, sucrose.

Mentions: Although M. pulcherrima is productive using a glycerol carbon source, a far more abundant feedstock is lignocellulose. Waste food, agricultural wastes or energy crops grown specifically for the purpose can be converted into a range of sugars through relatively inexpensive chemical or enzymatic processes [36]. The composition of the sugars obtained depends heavily on the method and source of the feedstock, and the main sugars are glucose, arabinose, xylose and cellobiose, and a range of oligosaccharides [37]. To establish its ability to utilise depolymerised lignocellulose, M. pulcherrima was cultivated on a wide range of sugars including lactose and sucrose (Figure 6). Biomass productivity for M. pulcherrima was higher in media containing glucose compared to any other sugar or combination of sugars. Provided glucose was present, any other sugar acted as an effective carbon source with little reduction in biomass yield. A possible explanation is that glucose induces M. pulcherrima to express enzymes capable of metabolising oligosaccharides, as occurs in a range of non-saccharomyces yeast [38]. Although M. pulcherrima was capable of growth on xylose, this resulted in reduced biomass productivity compared to glucose. M. pulcherrima struggles to grow on the arabinose aldehyde and lactose but metabolises sucrose extremely effectively, obtaining dry biomass content similar to glucose. Overall, M. pulcherrima can be cultivated effectively on a range of sugars, especially in the presence of glucose, indicating its suitability to utilize abundant biomass sources, such as lignocellulose.


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)

Biomass productivity of M. pulcherrima on a range of simple sugars. Optical density (O.D.) of the culture after 15 days. GLU, glucose; XYL, xylose; GLY, glycerol; ARA, arabinose; CELL, cellobiose; LAC, lactose; SUC, sucrose.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: Biomass productivity of M. pulcherrima on a range of simple sugars. Optical density (O.D.) of the culture after 15 days. GLU, glucose; XYL, xylose; GLY, glycerol; ARA, arabinose; CELL, cellobiose; LAC, lactose; SUC, sucrose.
Mentions: Although M. pulcherrima is productive using a glycerol carbon source, a far more abundant feedstock is lignocellulose. Waste food, agricultural wastes or energy crops grown specifically for the purpose can be converted into a range of sugars through relatively inexpensive chemical or enzymatic processes [36]. The composition of the sugars obtained depends heavily on the method and source of the feedstock, and the main sugars are glucose, arabinose, xylose and cellobiose, and a range of oligosaccharides [37]. To establish its ability to utilise depolymerised lignocellulose, M. pulcherrima was cultivated on a wide range of sugars including lactose and sucrose (Figure 6). Biomass productivity for M. pulcherrima was higher in media containing glucose compared to any other sugar or combination of sugars. Provided glucose was present, any other sugar acted as an effective carbon source with little reduction in biomass yield. A possible explanation is that glucose induces M. pulcherrima to express enzymes capable of metabolising oligosaccharides, as occurs in a range of non-saccharomyces yeast [38]. Although M. pulcherrima was capable of growth on xylose, this resulted in reduced biomass productivity compared to glucose. M. pulcherrima struggles to grow on the arabinose aldehyde and lactose but metabolises sucrose extremely effectively, obtaining dry biomass content similar to glucose. Overall, M. pulcherrima can be cultivated effectively on a range of sugars, especially in the presence of glucose, indicating its suitability to utilize abundant biomass sources, such as lignocellulose.

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