Through work originally designed to remove contaminants from soil, scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and their Belgium colleagues at Hasselt University have identified plant-associated microbes that can improve plant growth on marginal land.
The findings, published in the February 1, 2009 issue of Applied and Environmental Microbiology, may help scientists design strategies for sustainable biofuel production that do not use food crops or agricultural land.
“Biofuels are receiving increased attention as one strategy for addressing the dwindling supplies, high costs, and environmental consequences of fossil fuels,” said Brookhaven biologist and lead author Daniel (Niels) van der Lelie, who leads the Lab’s biofuels research program. “But competition with agricultural resources is an important socioeconomic concern.”
Ethanol produced by fermenting corn, for example, diverts an important food source — and the land it’s grown on — for fuel production. A better approach would be to use non-food plants, ideally ones grown on non-agricultural land, for biofuel production.
Van der Lelie’s team has experience with plants growing on extremely marginal soil — soil contaminated with heavy metals and other industrial chemicals. In prior research, his group has incorporated the molecular “machinery” used by bacteria that degrade such contaminants into microbes that normally colonize poplar trees, and used the trees to clean up the soil. An added benefit, the scientists observed, was that the microbe-supplemented trees grew faster — even when no contaminants were present.
“This work led to our current search for bacteria and the metabolic pathways within them that increase biomass and carbon sequestration in poplar trees growing on marginal soils, with the goal of further improving poplar for biofuel production on non-agricultural lands,” said co-author Safiyh Taghavi.
In the current study, the scientists isolated bacteria normally resident in poplar and willow roots, which are known as endophytic bacteria, and tested selected strains’ abilities to increase poplar growth in a controlled greenhouse environment. They also sequenced the genes from four selected bacterial species and screened them for the production of plant-growth promoting enzymes, hormones, and other metabolic factors that might help explain how the bacteria improve plant growth.
“Understanding such microbial-plant interactions may yield ways to further increase biomass,” van der Lelie said.
The plants were first washed and surface-sterilized to eliminate the presence of soil bacteria so the scientists could study only the bacteria that lived within the plant tissues – true endophytic bacteria. The plant material was then ground up so the bacterial species could be isolated. Individual strains were then supplemented with a gene for a protein that “glows” under ultraviolet light, and inoculated into the roots of fresh poplar cuttings that had been developing new roots in water. The presence of the endophytic bacteria was confirmed by searching for the glowing protein. Some bacterial species were also tested for their ability to increase the production of roots in the poplar cuttings by being introduced during the rooting process rather than afterward.The results
In the studies specifically looking at root formation, non-inoculated plants formed roots very slowly. In contrast, plant cuttings that were allowed to root in the presence of selected endophytes grew roots and shoots more quickly.
The analysis of genes and metabolically important gene products from endophytes resulted in the identification of many possible mechanisms that could help these microbes thrive within a plant environment, and potentially affect the growth and development of their plant host. These include the production of plant-growth-promoting hormones by the endophytic bacteria that stimulate the growth of poplar on marginal soils.
The scientists plan to conduct additional studies to further elucidate these mechanisms. “These mechanisms are of prime importance for the use of plants as feedstocks for biofuels and for carbon sequestration through biomass production,” van der Lelie said.
This study was funded by the Office of Biological and Environmental Research within DOE’s Office of Science, by Brookhaven’s Laboratory Directed Research and Development Fund, and by the Flanders Science Foundation and the Institute for the Promotion of Innovation by Science and Technology in Flanders, both in Belgium.
Karen McNulty Walsh | EurekAlert!
Further reports about: > Biomass > Burkholderia cepacia BU72 > Enterobacter sp. 638 > Plant Growth > agricultural land > agricultural resources > bacteria > bacterial species > biofuel production > endophytic bacteria > environmental risk > food crop > mass production > metabolic pathways > plant-associated microbes > poplar trees
Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering
Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Information Technology
17.07.2018 | Materials Sciences
17.07.2018 | Power and Electrical Engineering