Limits...
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

Fed-batch culture of M. pulcherrima a with additional nutrients added every 2 days until 24 days, then kept at 15°C for 12 days.
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Figure 8: Fed-batch culture of M. pulcherrima a with additional nutrients added every 2 days until 24 days, then kept at 15°C for 12 days.

Mentions: To increase the cell density, separate cultures were investigated under a fed-batch regime, using equal amounts of the four sugars and varying the amount of yeast extract, biotin and additional nitrogen (Table 1, Figure 8). To verify whether M. pulcherrima was capable of contamination-free growth in a fed-batch system the yeast was cultured in media made up in final effluent waste water. None of the reagents were sterilised prior to use. Each culture was fed every 2 to 3 days up to 24 days (25°C, 180 rpm) and then allowed to rest at 15°C for 12 days without agitation. Other than yeast extract, biotin and the carbon source all nutrients were supplied according to the OMP media, except phosphate, which was supplemented only at 15 days since the starting concentration high excess compared to the nutritional requirement on the yeast.


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)

Fed-batch culture of M. pulcherrima a with additional nutrients added every 2 days until 24 days, then kept at 15°C for 12 days.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 8: Fed-batch culture of M. pulcherrima a with additional nutrients added every 2 days until 24 days, then kept at 15°C for 12 days.
Mentions: To increase the cell density, separate cultures were investigated under a fed-batch regime, using equal amounts of the four sugars and varying the amount of yeast extract, biotin and additional nitrogen (Table 1, Figure 8). To verify whether M. pulcherrima was capable of contamination-free growth in a fed-batch system the yeast was cultured in media made up in final effluent waste water. None of the reagents were sterilised prior to use. Each culture was fed every 2 to 3 days up to 24 days (25°C, 180 rpm) and then allowed to rest at 15°C for 12 days without agitation. Other than yeast extract, biotin and the carbon source all nutrients were supplied according to the OMP media, except phosphate, which was supplemented only at 15 days since the starting concentration high excess compared to the nutritional requirement on the yeast.

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