Assessing an effective feeding strategy to optimize crude glycerol utilization as sustainable carbon source for lipid accumulation in oleaginous yeasts

• DOI: 10.1186/s12934-016-0467-x
• Publication Date: 2016-05-05T14:43:48Z
• Authors: Lorenzo Signori; Diletta Ami; Riccardo Posteri; Andrea Giuzzi; Paolo Mereghetti; Danilo Porro; Paola Branduardi
• Keywords: Glycerol; 2. Zero hunger; 0301 basic medicine; Principal Component Analysis; Chromatography, Gas; Crude glycerol; Cryptococcus curvatus; Fatty acids methyl esters (FAME); Flow-cytometry; Fourier transform infrared (FTIR) microspectroscopy; Lipomyces starkeyi; Principal component analysis (PCA); Rhodosporidium toruloides; Biotechnology; Bioengineering; Applied Microbiology and Biotechnology; Research; Basidiomycota; Crude glycerol; Cryptococcus curvatus; Fatty acids methyl esters (FAME); Flow-cytometry; Fourier transform infrared (FTIR) microspectroscopy; Lipomyces starkeyi; Principal component analysis (PCA); Rhodosporidium toruloides;; Fatty Acids; Bioengineering; Flow Cytometry; Applied Microbiology and Biotechnology; Lipids; Carbon; 12. Responsible consumption; 03 medical and health sciences; Microscopy, Fluorescence; Biofuels; Spectroscopy, Fourier Transform Infrared; Biomass; Biotechnology

Microbial lipids can represent a valuable alternative feedstock for biodiesel production in the context of viable bio-based economy. This be driven by cultivating some oleaginous microorganisms on crude-glycerol, 10 % (w/w) by-product produced during transesterification process from oils into biodiesel. Despite attractive, perspective is still economically unsustainable, mainly because impurities crude glycerol negatively affect microbial performances. In this view, selection best cell factory, together with development robust and effective are primary requirements. The present work compared versus pure as carbon sources lipid three different yeasts: Rhodosporidium toruloides (DSM 4444), Lipomyces starkeyi 70295) Cryptococcus curvatus 70022). An efficient yet simple feeding strategy avoiding lag phase caused growth was developed, leading to high biomass all tested yeasts. Flow-cytometry fourier transform infrared (FTIR) microspectroscopy, supported principal component analysis (PCA), were used non-invasive quick techniques monitor, compare analyze over time. Gas chromatography (GC) completed quali-quantitative description. Under these operative conditions, highest content (up 60.9 wt/wt) measured R. toruloides, while L. showed fastest consumption rate (1.05 g L−1 h−1). Being productivity most industrially relevant feature pursued, under presented optimized conditions (0.13 0.15 h−1 glycerol, respectively). Here we demonstrated that an sufficient preventing inhibitory effect enough ensure accumulation Single situ analyses allowed depicting comparing transition between occurring differently These data provide novel information exploited screening moving towards sustainable production.