Metabolic Flexibility ofYarrowia lipolyticaGrowing on Glycerol.
The yeastYarrowia lipolyticais a fascinating microorganism with an amazing metabolic flexibility. This yeast grows very well on a wide variety of carbon sources from alkanes over lipids, to sugars and glycerol.Y. lipolyticaaccumulates a wide array of industrially relevant metabolites. It is very tolerant to many environmental factors, above all the pH value. It grows perfectly well over a wide pH range, but it has been described, that the pH has a decisive influence on the metabolite pattern accumulated by this yeast. Here, we set out to characterize the metabolism of differentY. lipolyticastrains, isolated from various environments, growing on glycerol at different pH values. The conditions applied for strain characterization are of utmost importance. Shake flask cultures lead to very different results, when compared to controlled conditions in bioreactors regarding pH and aeration. Only one of the tested strains was able to accumulate high amounts of citric acid in shake flask experiments, whereas a group of six strains turned out to accumulate citric acid efficiently under controlled conditions. The present study shows that strains isolated from dairy products predominantly accumulate sugar alcohols at any given pH, when grown on glycerol under nitrogen-limitation.
Christian Doppler-Laboratory for Biotechnology of Glycerol, Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria; Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria.
Michael
M
Egermeier
Christian Doppler-Laboratory for Biotechnology of Glycerol, Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria; Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria.
Hannes
H
Russmayer
Christian Doppler-Laboratory for Biotechnology of Glycerol, Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria; Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria; ACIB GmbH, Austrian Centre of Industrial BiotechnologyVienna, Austria.
Michael
M
Sauer
Christian Doppler-Laboratory for Biotechnology of Glycerol, Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria; Department of Biotechnology, BOKU-Vienna Institute of Bio Technology (VIBT), University of Natural Resources and Life SciencesVienna, Austria.
Hans
H
Marx
bioreactor cultivation; citric acid; dairy derived yeasts; environmental strain isolation; glycerol metabolism; sugar alcohols