The Potential of Constructed Wetland Plants for Bioethanol Production

Five plant species from two Chinese constructed wetland (CW) environments were studied for the production of bioethanol using simultaneous saccharification and fermentation (SSF). Fourteen CW plant species were found in the constructed wetlands and four species (Phragmites australis, Fargesia spathacea F., Thalia dealbata, and Juncus effusus L.) containing the highest contents of holocellulose (between 50 and 55% d.b.) as well as a highly abundant invasive species (Eupatorium adenophorum) were selected for further study of bioethanol production. Among the selected species, P. australis, T. dealbata, and J. effusus L. exhibited high glucose conversion efficiencies between 42 and 46% of the sample dry mass. These three species were then subjected to SSF at 38 °C with Saccharomyces cerevisiae BY4742 and obtained ethanol titers between 30 and 35 g/L. These results indicate promise for the application of CW plants in second-generation biofuel production.