The microbial energy solution for biofuels and solar power The Biodesign team, in their Nature Review Microbiology perspective article, outlines the prospects for bioenergy. They believe the future of microbial bioenergy is brightened by recent advancements in genome technologies and other molecular-biology techniques. One species of bacteria, the human gut bacterium E. coli, has become the workhorse of the multi-trillion dollar global biotech industry.
Microorganisms can produce renewable energy in large quantities and without damaging the environment or disrupting food supply. The microbial communities must be robust and self-stabilizing, and their essential syntrophies must be managed. Pre-genomic, genomic and post-genomic tools can provide crucial information about the structure and function of these microbial communities. Applying these tools will help accelerate the rate at which microbial bioenergy processes move from intriguing science to real-world practice.
A recent International Herald Tribune article reviewed the status of having algae produce biofuel. Large-scale commercial production is at least five years away, according to most estimates, and it is still too early to say which methods, if any, will be economically viable, how much energy they may produce and what their effects on the environment might be. The U.S. National Renewable Energy Laboratory is focusing on the development of commercial co-products for algae, like ethanol or animal feed, which could help to improve profitability.
LiveFuels uses open ponds to grow algae that are indigenous to the local environment, hoping that this will avoid the invasion problem. Since algae need nutrients to grow, including nitrogen and phosphorous, the company plans to feed agricultural runoff water – polluted with nitrogen and phosphorous fertilizers – into its ponds, combining energy production with water treatment.
Another company, Bionavitas, of Redmond, Washington, also grows native algae, but in deep, narrow canals, with a special optical system to bring light to the algae beneath the surface. It too hopes to harness nutrients from polluted wastewater; and because intense carbon dioxide inputs can speed growth, it envisages setting up sites next to a factory that could funnel smokestack emissions directly into its canals. Michael Weaver, the chief executive, said that Bionavitas aimed to use “the whole algae” to produce biodiesel, ethanol, nutriceuticals and products currently derived from petroleum.
Vertigro, a U.S. company based in Vancouver, Canada, is testing single varieties of algae, grown in bioreactors that resemble hanging plastic bags, to see which grows best in a closed environment and produces the most oil. Its business plan is to sell its system to companies that would use it for commercial biofuel production, said Glen Kertz, chief executive of Valcent Products, a partner in Vertigro with Global Green Solutions, a sustainable energy development business.
In Seattle, Blue Marble Energy is putting algal biomass in anaerobic digesters to produce industrial chemicals and methane. The latter is combusted in a turbine to generate electricity and could also be used in fuel cells, said the chief executive, Kelly Ogilvie. Saleable byproducts include ammonia, anhydrous ammonia, and other industrial chemicals currently made with petroleum.
From Sciencedaily, to date, approximately 75 genomes are available from microorganisms that have a role in bioenergy production. These include 21 genomes from methane producing archaea, 24 genomes from bacteria that can produce hydrogen or electricity, and 30 genomes from cyanobacteria that are potential biodiesel producers. At least half of the completed microbial genomes that are relevant to bioenergy were released in the past 2 years, and more than 80 bioenergy-related genomes are currently being sequenced.
Biodesign researchers outline paths where bacteria are the best hope in producing renewable energy in large quantities without damaging the environment or competing with our food supply.
Two distinct, but complementary approaches will be needed. The first is to use microbes to convert biomass to useful energy. 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 uses 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. Both approaches currently are intensive areas of biofuel research at the Biodesign Institute, which has a joint project with petroleum giant BP to harvest photosynthetic bacteria to produce renewable liquid fuels, such as biodiesel.