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News Release

August 25, 2005

Bacteria Work Best in Diverse, Unified Communities, Research Finds

Neighbourhood diversity and unity help communities thrive — even in the world of bacteria, new research by a University of Guelph professor reveals.

Jonathan Newman of the Department of Environmental Biology has found that the speed at which bacteria perform various jobs is directly linked to the number of different species that live and work in a particular bacterial community. The results of his study were released today in Nature.

The findings have important implications for the way microbiologists view bacterial communities, said Newman, who worked on the study with scientists from Oxford University and Britain’s NERC Centre for Ecology and Hydrology. "Rather than search for 'superbugs' that are capable of breaking down a pollutant, it might be better to search for efficient communities that work particularly well together."

It’s widely known that bacteria provide innumerable services such as breaking down pollutants and municipal waste. But unravelling the intricacies of just how these services are provided has been a particular challenge for microbiologists, Newman said. "The biodiversity and complexity of these communities are immense."

So instead of tackling these bacterial communities head-on, Newman and his collaborators deconstructed them. They took samples from water-filled tree holes to determine each species they contained and then reconstructed the communities in bottles in a laboratory. They then measured the rate at which each community worked to decompose leaf litter, a crucial service by which bacteria recycle nutrients to plants.

The researchers discovered that the number of species working in unison was significantly important in determining the rate at which the leaves were broken down. The process was most efficient when many different species worked together, the study found.

"Bacteria are of vital importance for many services that we take for granted, so any step toward understanding how these communities operate is significant," said Thomas Bell, lead author from Oxford University and currently a doctoral student of Newman’s.

This research is an extension of a previous study conducted by the group with was published in Science in June. Using bacterial samples taken from similar water-filled tree holes, the researchers discovered the size of the environment the bacteria live in is directly related to the amount of biodiversity, or number of species, it contains.

This has long been known to be the case with larger species of plants and animals, but until now, scientists thought the relationship did not hold for the microbial world, Newman said.

"People have suggested that this relationship doesn’t hold true for bacteria, and we’ve shown that, at least sometimes, it does. This implies that commonly understood processes in ecology might operate on microbial scales."