title: Lipid production by yeasts growing on biodiesel-derived crude glycerol: strain selection and impact of substrate concentration on the fermentation efficiency.
abstract: OBJECTIVE
  To screen yeasts in relation to the potential to produce single cell oil (SCO) from biodiesel-derived glycerol and to enhance SCO production in Lipomyces starkeyi and Rhodosporidium toruloides yeasts.
  
  
  RESULTS
  Yarrowia lipolytica, Cryptococcus curvatus, R. toruloides and L. starkeyi were grown in nitrogen-limited flask cultures. Yarrowia lipolytica strains produced citric acid and mannitol. Lipomyces starkeyi DSM 70296 and R. toruloides NRRL Y-27012 showed potential for SCO production, and were cultivated at increasing the initial glycerol concentrations with the initial nitrogen concentration remaining constant. Significant biomass and SCO production were reported even in cultures with high initial glycerol concentrations (i.e. 180 g l(-1) ). Lipid quantities of c. 12 g l(-1) (lipid in dry cell weight 35-40%) were obtained for both L. starkeyi and R. toruloides, quite high values compared with literature values for oleaginous micro-organisms growing on glycerol. However, these strains exhibited different kinetic profiles in the synthesis of intracellular polysaccharides. Lipomyces starkeyi produced a significant quantity of polysaccharides (c. 7 g l(-1) ). The yeast lipids contained mainly oleic and palmitic and to a lesser extent linoleic and stearic acids.
  
  
  CONCLUSIONS
  Lipomyces starkeyi and R. toruloides are potential SCO producers from crude glycerol.
  
  
  CONCLUSIONS
  Very scarce numbers of reports have indicated the production of SCO by L. starkeyi and R. toruloides growing on glycerol. We report here that these yeasts are able efficiently to convert raw glycerol into SCO, while L. starkeyi also synthesizes intracellular polysaccharides in marked quantities.
authors: Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece.
authors: S S
authors: SS
authors: Tchakouteu
authors: O
authors: O
authors: Kalantzi
authors: Chr
authors: C
authors: Gardeli
authors: A A
authors: AA
authors: Koutinas
authors: G
authors: G
authors: Aggelis
authors: S
authors: S
authors: Papanikolaou
mesh_terms: D001487:Basidiomycota / Q000254:growth & development / Q000378:metabolism*; D056804:Biofuels; D018533:Biomass; D019343:Citric Acid / Q000378:metabolism; D005285:Fermentation; D005990:Glycerol / Q000378:metabolism*; D008055:Lipids / Q000096:biosynthesis*; D055160:Lipomyces / Q000378:metabolism*; D015003:Yeasts / Q000254:growth & development / Q000378:metabolism
chemical_list: D056804:Biofuels; D008055:Lipids; D019343:Citric Acid; D005990:Glycerol
keywords: Lipomyces starkeyi; Rhodosporidium toruloides; biodiesel-derived glycerol; intracellular polysaccharides; oleaginous yeasts; single cell oil