The effects of ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate on the production of 1,3-propanediol from crude glycerol by microbial consortium
- 84 Downloads
Ionic liquids (ILs) as “green” solvents have been widely used owing to their excellent properties, e.g., for biodiesel production. Crude glycerol as a by-product in biodiesel production is an ideal feedstock for the microbial production of 1,3-propanediol (PDO), which is a versatile bulk chemical. PDO can be produced by microbial consortium with the advantages of high substrate tolerance and narrow by-product profile. In the present study, the effect of IL 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([Emim][TfO]) was evaluated on the capacity of PDO production from crude glycerol by microbial consortium DL38-BH. In the batch fermentation at 60 g/L crude glycerol and 10 g/L [Emim][TfO], the concentration and yield of PDO from glycerol increased from 23.14 g/L and 0.45 mol/mol to 31.17 g/L and 0.60 mol/mol, respectively. Our results showed that [Emim][TfO] decreased the ratio of intracellular NADH to NAD+ and increased the concentration of 3-HPA during batch fermentation. The activities of three key enzymes in glycerol metabolism were stimulated by [Emim][TfO] during the batch fermentation by microbial consortium DL38-BH. Compared to the control, the proportion of Klebsiella genus which could convert glycerol to PDO increased significantly from 79.19% to 89.49% and the other genera that did not produce PDO were dramatically decreased (P < 0.05) at the end of batch fermentation. This work demonstrated that [Emim][TfO] significantly improved the concentration and yield of PDO from crude glycerol by adjusting microbial community during batch fermentation by microbial consortium.
Keywords1,3-Propanediol Microbial consortium Ionic liquids Crude glycerol
This work was supported by the National Natural Science Foundation of China (Grant no. 21476042) and the Fundamental Research Funds for Central Universities (DUT17ZD209). Thanks to Yan Xing for modifying the grammars in the article.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- 8.Alivisatos AP, Blaser MJ, Brodie EL, Chun M, Dangl JL, Donohue TJ, Dorrestein PC, Gilbert JA, Green JL, Jansson JK, Knight R, Maxon ME, McFall-Ngai MJ, Miller JF, Pollard KS, Ruby EG, Taha SA (2015) A unified initiative to harness Earth’s microbiomes. Science 350(6260):507–508CrossRefPubMedGoogle Scholar
- 41.Lowery HO, Rosebrough J, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275Google Scholar
- 43.Wang JF, Xiu ZL, Fan SD (2001) Determination of glycerol concentration during the fermentation of glycerol to 1,3-propanediol. Ind Microbiol 31:33–35 (Chinese) Google Scholar