title: Systematic development of a two-stage fed-batch process for lipid accumulation in Rhodotorula glutinis.
abstract: The application of oleaginous yeast cells as feed supplement, for instance in aqua culture, can be a meaningful alternative for fish meal and oil additives. Therefore, a two-stage fed-batch process split into growth and lipogenesis phase was systematically developed to enrich the oleaginous yeast Rhodotorula glutinis Rh-00301 with high amounts of lipids at industrial relevant biomasses. Thereby, the different carbon sources glucose, sucrose and glycerol were investigated concerning their abilities to serve as a suited raw material for growth and/or lipid accumulation. With the background of economic efficiency C/N ratios of 40, 50 and 70 were investigated as well. It became apparent that glycerol is an improper carbon source most likely because of the passive diffusion of this compound caused by absence of active transporters. The opposite was observed for sucrose, which is the main carbon source in molasses. Finally, an industrially applicable process was successfully established that ensures biomasses of 106±2gL-1combined with an attractive lipid content of 63±6% and a high lipid-substrate yield (YL/S) of 0.18±0.02gg-1in a short period of time (84h). Furthermore, during these studies a non-negligible formation of the by-product glycerol was detected. This characteristic of R. glutinis is discussed related to other oleaginous yeasts, where glycerol formation is absent. Nevertheless, due to modifications in the feeding procedure, the formation of glycerol could have been reduced but not avoided.
authors.affiliation: Berlin University of Technology, Institute of Biotechnology, Berlin, Germany.
authors.forename: Eric
authors.initials: E
authors.lastname: Lorenz
authors.affiliation: Berlin University of Technology, Institute of Biotechnology, Berlin, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Runge
authors.affiliation: Berlin University of Technology, Institute of Biotechnology, Berlin, Germany.
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Marbà-Ardébol
authors.affiliation: Research and Teaching Institute for Brewing in Berlin, Department Bioprocess Engineering and Applied Microbiology, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Schmacht
authors.affiliation: Berlin University of Technology, Institute of Biotechnology, Berlin, Germany; Research and Teaching Institute for Brewing in Berlin, Department Bioprocess Engineering and Applied Microbiology, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Stahl
authors.affiliation: Research and Teaching Institute for Brewing in Berlin, Department Bioprocess Engineering and Applied Microbiology, Germany. Electronic address: m.senz@vlb-berlin.org.
authors.forename: Martin
authors.initials: M
authors.lastname: Senz
mesh_terms: D061249:Batch Cell Culture Techniques / Q000379:methods*; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D007218:Industrial Microbiology; D008055:Lipids / Q000096:biosynthesis*; D012248:Rhodotorula / Q000254:growth & development*
chemical_list: D008055:Lipids; D002244:Carbon; D005947:Glucose; D005990:Glycerol
keywords: C/N ratio; Carbon source; Oleaginous yeast; Process development; Rhodotorula glutinis; Two-stage fed-batch