London, July 11 : Scientists at the Biodesign Institute at Arizona State University say that two complementary approaches may help use microorganisms to produce renewable energy in large quantities, without damaging the environment or competing with the food supply.
The researchers say that the first approach is to use microbes to convert biomass to useful energy.
According to them, different microorganisms can grow without oxygen to take this abundant organic matter, and convert it to useful forms of energy such as methane, hydrogen or even electricity.
The second approach, they say, is to use bacteria or algae that can capture sunlight to produce new biomass that can be turned into liquid fuels like biodiesel, or converted by other microorganisms to useful energy.
Biodesign Institute's Bruce Rittmann, Rosa Krajmalnik-Brown, and Rolf Halden say that both approaches currently are intensive areas of biofuel research at the institute, which has a joint project with petroleum giant BP to harvest photosynthetic bacteria to produce renewable liquid fuels, such as biodiesel.
The researchers believe that the future of microbial bioenergy is brightened by recent advancements in genome technologies, and other molecular-biology techniques.
They, however, add that even if one picks the idea "bug" for generating bioenergy, growing, maintaining, and optimising conditions for its use remains a daunting challenge in terms of scalability and reliability.
"Microbial communities that are used to harvest energy must be resilient to fluctuations in environmental conditions, variations in nutrient and energy inputs and intrusion by microbial invaders that might consume the desired energy product," Nature magazine quoted the authors as saying.
They say that the key to large-scale success in microbial bioenergy is managing the microbial community so that that it delivers the desired bioenergy product reliably and at high rate.
The authors say that in the absence of such molecular techniques, scientists' understanding of methanogenic communities progressed through slow, incremental advances over several decades. They believe that society cannot wait decades for new bioenergy sources.
The researchers feel that scientists should now take full advantage of the existing pre-genomic, genomic, and post-genomic tools to understand microorganisms involved in bioenergy production so as to speed up scientific and technological advances.
The authors conclude: "Information from these tools, when properly integrated with advanced engineering tools and material, should accelerate the rate at which microbial bioenergy processes can be converted from the realm of intriguing science to real world practice."