Getting lipids from glycerol: new perspectives on biotechnological exploitation of Candida freyschussii

Microbial Cell Factories

Research

Michele Maria Bianchi¹  Teresa Rinaldi¹  Maddalena Rossi²  Alan Leonardi²  Stefano Raimondi²  Alberto Amaretti² 

[1] Department of Biology and Biotechnology Charles Darwin, University of Rome ‘La Sapienza’, Piazza Aldo Moro 5, 00185, Rome, Italy;Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 183, 41100, Modena, Italy;

关键词: Lipid Production;    Crude Glycerol;    Volumetric Productivity;    Oleaginous Yeast;    Glycerol Conversion;   

DOI  :  10.1186/1475-2859-13-83

 received in 2014-02-12, accepted in 2014-05-30,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundMicrobial lipids represent a valuable alternative feedstock for biodiesel production when oleaginous microbes are cultured with inexpensive substrates in processes exhibiting high yield and productivity. In this perspective, crude glycerol is among the most promising raw materials for lipid production, because it is the costless residual of biodiesel production. Thus, cultivation of oleaginous yeasts in glycerol-based media is attracting great interest and natural biodiversity is increasingly explored to identify novel oleaginous species recycling this carbon source for growth and lipid production.ResultsThirty-three yeasts strains belonging to 19 species were screened for the ability to grow and produce intracellular lipids in a pure glycerol-based medium with high C/N ratio. A minority of them consumed most of the glycerol and generated visible lipid bodies. Among them, Candida freyschussii ATCC 18737 was selected, because it exhibited the highest lipid production and glycerol conversion yield. Lipid production in this strain was positively affected by the increase of C/N ratio, but growth was inhibited by glycerol concentration higher than 40 g/L. In batch cultures, the highest lipid production (4.6 g/L), lipid content of biomass (33% w/w), and lipid volumetric productivity (0.15 g/L/h) were obtained with 40 g/L glycerol, during the course of a 30-h process. Fed-batch cultivation succeeded in preventing substrate inhibition and in achieving a high cell-density culture. The improved lipid production and volumetric productivity reached the remarkable high level of 28 g/L and 0.28 g/L/h, respectively. The lipids accumulated by C. freyschussii ATCC 18737 have similar fatty acid composition of plant oil indicating their potential use as biodiesel feedstock. Calculated physicochemical properties of a biodiesel produced with the lipids from C. freyschussii ATCC 18737 are expected to meet the European and American standards, being equal to those of rapeseed and palm biodiesel.ConclusionsC. freyschussii ATCC 18737 could be considered an interesting microorganism for utilization in biofuel industry. Cultivation of this yeast in media containing crude glycerol should be investigated deeper in order to evaluate whether it may find application in the valorization of the waste of biodiesel manufacturing.

【 授权许可】

Unknown   
© Raimondi et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.