Thermophilic enrichment of microbial communities in the presence of the ionic liquid 1-ethyl-3-methylimidazolium acetate
Article first published online: 1 OCT 2012
© 2012 UC Davis
Journal of Applied Microbiology
Volume 113, Issue 6, pages 1362–1370, December 2012
How to Cite
Reddy, A.P., Simmons, C.W., Claypool, J., Jabusch, L., Burd, H., Hadi, M.Z., Simmons, B.A., Singer, S.W. and VanderGheynst, J.S. (2012), Thermophilic enrichment of microbial communities in the presence of the ionic liquid 1-ethyl-3-methylimidazolium acetate. Journal of Applied Microbiology, 113: 1362–1370. doi: 10.1111/jam.12002
- Issue published online: 16 NOV 2012
- Article first published online: 1 OCT 2012
- Accepted manuscript online: 7 SEP 2012 08:54AM EST
- Manuscript Accepted: 29 AUG 2012
- Manuscript Revised: 26 AUG 2012
- Manuscript Received: 27 JUN 2012
- 1-ethyl-3-methylimidazolium acetate;
- ionic liquid tolerance;
- microbial community
The aim of the study was to develop an approach to enrich ionic liquid tolerant micro-organisms that efficiently decompose lignocellulose in a thermophilic and high-solids environment.
Methods and Results
High-solids incubations were conducted, using compost as an inoculum source, to enrich for thermophilic communities that decompose switchgrass in the presence of the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]). Ionic liquid levels were increased from 0 to 6% on a total weight basis incrementally. Successful enrichment of a community that decomposed lignocellulose at 55°C in the presence of 6% [C2mim][OAc] was achieved, when the [C2mim][OAc] level was increased stepwise from 2% to 4% to 5% to 6%. Pyrosequencing results revealed a shift in the community and a sharp decrease in richness, when thermophilic conditions were applied.
A community tolerant to a thermophilic, high-solids environment containing 6% [C2mim][OAc] was enriched from compost. Gradually increasing [C2mim][OAc] concentrations allowed the community to adapt to [C2mim][OAc].
Significance and Impact of the Study
A successful approach to enrich communities that decompose lignocellulose under thermophilic high-solids conditions in the presence of elevated levels of [C2mim][OAc] has been developed. Communities yielded from this approach will provide resources for the discovery of enzymes and metabolic pathways relevant to biomass pretreatment and fuel production.