posted on July 30: McMaster biologists help decode beneficial bacterium

It has taken four years, but an international consortium that includes McMaster researchers has decoded the genome sequence of a bacterium that could play a key role in reducing the use of chemical fertilizers.

The sequence revealed that the bacterium contains more than 6,000 genes or roughly one-fifth the number present in the human genome.

This research contributes significantly to the goal of achieving environmentally safe and economically sustainable food crops.

The bacterium, Sinorhizoblum meliloti (S. meliloti) is commonly applied to alfalfa crops as part of a natural fertilization process.

Until now, scientists did not have a comprehensive understanding of the bacterium's genome. S. meliloti is unusual in that its genome is made up of three chromosomes, while most common bacteria have only one.

Three teams of scientists, from McMaster (teamed with the Universitat Bielefeld, Germany), Stanford University, France and Belgium, were responsible for sequencing each of the three chromosomes. The integration of their research appears in the most recent issue of the international journal, Science.

Turlough Finan, chair of biology and one of the lead investigators, believes that now that the sequence of genes is known, researchers can infer many processes and investigate the functions of many genes more efficiently.

“If we can understand how the bacterium works, we may be able to improve the nitrogen-fixation process and increase the range of plants it can interact with.”

The team at McMaster includes Finan and Brian Golding, a professor of biology and a specialist in bio-informatics. Other members are Alison Cowie, research technologist; Ismael Hernandez-Lucas, postdoctoral candidate; Kim Wong, master's candidate and Patrick Chain, a recent M.Sc. graduate.