Isoprene Production from Municipal Wastewater Biosolids by Engineered Archaeon Methanosarcina acetivorans

Featured Application Engineered Methanosarcina acetivorans can be introduced to municipal wastewater to produce renewable bioisoprene. Wastewater biosolids are a promising feedstock for production of value-added renewable chemicals. Methane-producing archaea (methanogens) are already used to produce renewable biogas via the anaerobic treatment of wastewater. The ability of methanogens to efficiently convert dissolved organic carbon into methane makes them an appealing potential platform for biorefining using metabolic engineering. We have engineered a strain of the methanogen Methanosarcina acetivorans to produce the volatile hemiterpene isoprene in addition to methane. The engineered strain was adapted to grow in municipal wastewater through cultivation in a synthetic wastewater medium. When introduced to municipal wastewater the engineered methanogens were able to compete with the indigenous microorganisms and produce 0.97 mM of isoprene (65.9 +/- 21.3 g per m(3) of effluent). The production of isoprene in wastewater appears to be dependent on the quantity of available methanogenic substrate produced during upstream digestion by heterotrophic fermenters. This shows that with minimal adaptation it is possible to drop-in engineered methanogens to existing wastewater environments and attain value-added products in addition to the processing of wastewater. This shows the potential for utilizing methanogens as a platform for low-cost production of renewable materials without expensive feedstocks or the need to build or adapt existing facilities.

Automated summary

Research on engineered Methanosarcina acetivorans in municipal wastewater to produce renewable bioisoprene for value-added chemicals. The engineered strain can adapt to grow and produce bioisoprene in municipal wastewater. The potential for utilizing methanogens as a platform for low-cost production of renewable materials is demonstrated through the production of bioisoprene using available methane substrate in wastewater.