Plant Growth Promoting Bacteria for Efficient Biofuel Production

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Hasselt University in Belgium have identified plant-associated microbes that can improve plant growth on marginal land. The findings may help scientists design strategies for sustainable biofuel production that do not use food crops or agricultural land.

In a previous study, the team led by Daniel van der Lelie successfully developed microbial gene-expressing poplar trees that can degrade soil contaminants. An added bonus, the researchers observed, was that the poplar trees grew faster even when no contaminants were present. This led to the search for bacteria that increase biomass and carbon sequestration in poplar trees growing on marginal soils.

The team isolated endophytic bacteria present in poplar and willow roots and tested selected strains’ abilities to increase plant growth in a controlled greenhouse environment. Cuttings inoculated with Enterobacter sp. 638 and Burkholderia cepacia BU72 showed up to 50 percent increase in biomass production. Analysis of genes from four bacterial species resulted in the identification of possible mechanisms that could help these microbes thrive within a plant environment, including the production of plant growth-promoting hormones.

The complete article is available at http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=874 The paper published by Applied and Environmental Microbiology is available at http://dx.doi.org/10.1128/AEM.02239-08