Unlikely allies in the war against waste

Families of microbes might become power sources of the future to gobble up waste and spit out pure energy as hydrogen and methane…

Families of microbes might become power sources of the future to gobble up waste and spit out pure energy as hydrogen and methane, writes Dick Ahlstrom

Bacteria may become an important energy source as supplies of fossil fuels diminish. Colonies of bugs can deliver hydrogen and methane to heat our homes and cook our food, while also gobbling up unwanted waste.

The new Charles Parsons Energy Research Awards announced last December by the Department of Communications, Marine and Natural Resources were designed to throw up innovative research into new energy sources and Parsons related research funded at NUI Galway is doing just that.

A lecturer in the Department of Microbiology and the Environmental Change Institute, Dr Vincent O'Flaherty is leading a seven-year, €2 million research study that involves about 20 academics and students. The goal is to streamline the production of methane and hydrogen by microorganisms.

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"We have been working in the area for several years. What the Parsons (award) does is bring together a multidisciplinary team under a single grant," says Dr O'Flaherty. "The seven-year funding has been particularly helpful for us."

He and Dr Donal Leech are the two academic researchers linked to the project. "The subject is energy production using bacteria. The thing is to get the microbes to do the thing as efficiently as possible."

This involves making them as happy as possible, ensuring just the right growing conditions and nutrients to encourage them to release more energy as combustible gasses. "The microbes usually live in biofilms and are well capable of producing methane from a range of organic sources."

It is not just a matter of throwing in lots of tasty sewage or waste from sugar production, he adds. The organisms live in complex colonies with harmful waste from one species providing useful food for another.

They interact in very specific ways and optimising the colonies to produce more methane or hydrogen is not straightforward, he maintains. "We are still finding out about the microorganisms involved.

"Where the research is going now is making the process as efficient as possible. If you could know more about the interactions that occur you could drive the biochemical pathways that make methane production more efficient."

The mix of organisms that make up a biofilm can be difficult to establish but so too are their interactions. Also, the biofilms that produce methane, rather than hydrogen, also include some of the oldest microbes on earth, dating back billions of years.

While bacteria digesting an organic substrate readily produce hydrogen, the archaea embedded in biofilms and working in concert with bacteria are able to produce methane, a more valuable fuel better known as natural gas.

Ironically, much of the research in this area was actually pursued as a way to dispose of waste, and not specifically to produce energy. "Now, with the energy environment we live in the delivery of energy products is becoming more significant," says Dr O'Flaherty.

Energy systems based on bacteria can deliver useful amounts of energy, he believes. "It is particularly suited to decentralised production of energy."

The great advantage is the bacterial colonies are self sustaining, there are endless supplies of organic material and waste to keep the colony fed and the energy stream produced is sustainable and independent of fossil sources.

The Department of Communications, Marine and Natural Resources has already announced seven major awards to third-level institutions under the Charles Parsons Energy Research Awards, and tomorrow invites researchers to apply to join these initiatives. Details will be placed in newspapers and leading journals. Information is also available on the department's website, www.dcmnr.ie.