Finding Genetic Gold in the Amazon

Newswise — Brazilian scientists may have found a new source for plastics and life saving medicines by cracking the genetic code of Chromobacterium violaceum, a free-living bacterium that commonly floats along the Rio Negro river in the Amazon rainforest.

The complete genome sequence, which will be published in a future issue of the Proceedings of the National Academy of Sciences, was released on the journal's Web site today. More than 100 members of the Brazil National Genome Project helped sequence the bacterial pest, which is linked to rare, but fatal infections.

However, it was the positive aspects of Chromobacterium that most interested the researchers. The bacterium produces a pigment, called violaceum, which has been tested as a potential skin treatment.

Studies that analyzed a small fraction of Chromobacterium genes suggested that the bug exerts a range of effects with both medical and business applications.

Scrutinizing the full repertoire of genes confirmed these initial impressions, and added considerable new insights as well. Not only might Chromobacterium help fight diseases like cancer, it contains specific genes that order proteins to naturally break down gold, act as insecticides, root out pollution, and synthesize a group of acids that could represent a possible alternative to plastics.

In sequencing the entire genome of Chromobacterium, the Brazilian team hopes that they can fully understand how such a small bug produces such an enormous range of positive effects.

"We often use genetic sequencing to determine the underlying cause of a problem," said Dr. Andrew J. Simpson of the Ludwig Institute for Cancer Research, the coordinator of the study. "But this is an attempt to find out how an organism can be harnessed to make products that may be healthier for us and safer for the environment."

Interestingly, the genetic advantages found in Chromobacterium may be based on the harsh environment it is forced to adapt to. There is an abundance of these bacteria in tropical climates despite a scarcity of nutrients, and high levels of radiation and other toxic threats.

The Brazilian researchers caution that much work needs to be done before Chromobacterium becomes a new type of assembly line for biotechnology. But with a host of other tropical organisms offering possible benefits as well, they believe that the Amazon is an important source of opportunity.

"The identification of such genetic resources of Chromobacterium justifies sequencing efforts of other tropical organisms," said study author Dr. Ana Tereza Ribeiro de Vasconcelos, a bioinformatics specialist at the National Laboratory for Scientific Computation in Petropolis, Brazil. "In addition to having direct benefits for industry, this would provide a further reason to preserve the precious ecosystems where these organisms are found."