Synthetic Microbial Communities Help Bioenergy Crops Grow

August 21, 2024
By JBEI

Assembled communities of microbes could be added to bioenergy crop soils to improve biomass and biofuel production

The Science: The area of soil surrounding a plant’s roots, known as the rhizosphere, contains a diverse community of microbes that impact the plant. It’s possible that scientists can manipulate the rhizosphere in a way that is beneficial to the plant, but doing so is difficult. Synthetic microbial communities designed by scientists have been seen as a good alternative, as they have the potential to positively impact their plant host. In this study, researchers created a synthetic microbial community for evaluating how growth conditions affect what’s in the microbial community, and for seeing how the community impacted its plant host. 

The Impact: Researchers assembled a synthetic microbial community composed of 57 bacterial strains and applied it to sorghum, a bioenergy crop. They found that the community had a positive effect on sorghum’s growth, both in the lab and in the field. It also changed the amount and composition of lignin within the root tissue. Previous research has shown that these types of alterations could enhance the conversion of plant tissue into bioethanol. With sorghum being a key bioenergy crop, it is possible that synthetic microbial communities could therefore be used to improve biofuel production. 

Summary: There has been commercial interest in using microbial soil and rhizosphere amendments to improve agricultural activity, but doing so has been challenging to date with very few successful outcomes. Researchers developed a synthetic microbial community made up of microbes that are commonly found in the sorghum rhizosphere. They specifically selected a community of microbes that they hypothesized would be well-suited to support the rhizosphere and root colonization. They tested this community’s application in sorghum in three environments — in media, in the plant under laboratory conditions, and in the field. 

In addition to their findings on the microbial community’s impact on its plant host, the researchers also demonstrated that community engraftment depends on the growth environment and how diverse the microbial community is — and that engraftment may not need to be used over long periods of time to achieve specific desired outcomes. These findings show the potential of using synthetic microbial communities in the field to improve agricultural activity.

Publication: Fonseca-Garcia, Citlali, Pettinga, D., Wilson, A., et al. Defined synthetic microbial communities colonize and benefit field-grown sorghum. The ISME Journal (2024). [DOI: 10.1093/ismejo/wrae126] 

Written by Emily Nelson