Publication Date:
2017-03-18
Description:
In an era of ever-increasing energy demands, a promising technology is being developed: the use of oleaginous microorganisms such as Yarrowia lipolytica to convert waste materials into biofuels. Here, we constructed two Y. lipolytica strains that displayed both increased lipid accumulation and a more efficient use of biomass-derived sugars, including glucose, fructose, galactose, and inulin. The first strain, Y. lipolytica YLZ150, was derived from the French wild-type strain W29. It had inhibited triacylglycerol mobilization ( ∆tgl4 ) and β-oxidation (∆pox1-6 ), and it overexpressed GPD1 , DGA2 , HXK1 , the native Leloir pathway, SUC2 from Saccharomyces cerevisiae , and INU1 from Kluyveromyces marxianus . The second strain, Y. lipolytica Y4779, was derived from the Polish A-101 strain. It had inhibited β-oxidation (∆mfe2 ) and overexpressed GPD1 , DGA1 , HXK1 , YHT3, SUC2 , and INU1 . In the first experiment, strain YLZ150 was batch-cultured in media containing different hexoses; the highest values for lipid concentration and yield of lipids from the substrate were obtained using fructose (20.3 g dm -3 and 0.14 g g -1 , respectively). In the second experiment, we grew the two strains in fed-batch cultures to examine lipid biosynthesis from inulin (a fructose polymer). For Y4779, the lipid concentration was 10.3 g dm -3 and the yield of lipids from substrate was 0.07 g g -1 ; in contrast, for YLZ150, these values were 24 g dm -3 and 0.16 g g -1 , respectively. The YLZ150 strain is thus able to efficiently exploit glucose, fructose, galactose, sucrose, and inulin for lipid biosynthesis.
Print ISSN:
0749-503X
Electronic ISSN:
1097-0061
Topics:
Biology
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