RHIZOBIUM

Rhizobium meliloti is a nitrogen-fixing bacterium. It naturally colonises the roots of legumes, converting nitrogen from the air into soluble nitrates that plants can use. A new variety of the bacterium has now been genetically engineered. It contains additional genes coding for the nitrogen-fixing enzyme, in the hopes of increasing yields. Farmers have used the wild strain of this bacterium for about 75 years as "insurance that they will get good yields, but whether the genetically altered bacteria can actually enhance yields is under question. The new bacteria were also given foreign antibiotic-resistant genes. They were approved by the USA Environmental Protection Agency (EPA) on September 16, 1997, and can be used in alfalfa fields throughout the USA starting now.

An expert scientist,s evaluation of the EPA,s official scientific review showed that the risk assessment for environmental effects contained little hard data. He said it was simply "speculation that the organism would be harmless. The review didn't adequately address issues like whether or not the bacteria would alter the ecology or fertility of the soil, or cause increases in antibiotic-resistant organisms. The basis for approval was that "the parent organism has been used without ill effect.