WASHINGTON _ Environmental Protection Agency scientistshave concluded that Rhizobium meliloti, genetically engineered toserve as a better alfalfa fertilizer, is safe, according to a draft riskassessment report. The Rhizobium product (called RMB PC-2),which has been in development since 1987, could be cleared forcommercial release after a final risk assessment report is prepared.

On Wednesday, the EPA's Biotechnology Science AdvisoryCommittee (BSAC) met to review the EPA's draft risk assessment,to answer a list of 28 questions prepared by EPA scientists and tohear public comments. RMB PC-2, originally developed byBiotechnica International, is now a product of UrbanaLaboratories/Research Seeds of St. Joseph, Mo.

Rhizobium meliloti is a native soil dweller and is one of severalspecies of bacteria which convert atmospheric nitrogen, unusable bymost living organisms, into useful forms of nitrogen needed for life.This process, called nitrogen fixation, is accomplished by thebacteria in a symbiotic relationship with legumes (certain alfalfavarieties are members of the legume family).

RMB PC-2 was engineered for improved nitrogen fixation functionsin order to boost the amount of nitrogen available to the alfalfa plantand thus increase crop yields. The genetic alterations involvedaddition of genes involved in nitrogen fixation and photosynthesis.In addition, a marker gene expressing resistance to two antibiotics,streptomycin and spectinomycin, was added for identificationpurposes.

The product, if cleared by EPA for wide-scale commercial use,would represent the first genetically engineered organism to wend itsway through the EPA's regulatory process under the 1976 ToxicSubstances Control Act (TSCA). RMB PC-2 is subject topremanufacture notification (PMN) requirements under TSCAbecause it is intergeneric (i.e., it contains genetic material fromsource organisms of different genera), it is a biofertilizer and it isintended for commercialization.

On Wednesday, consumer and environmental advocates criticizedthe EPA's draft risk assessment report on RMB PC-2, saying releaseof the organism would be irreversible and could lead to the transferof antibiotic resistance to other pathogenic organisms. They alsoargued that the product could unintentionally boost weed production,just as it boosts alfalfa production.

"We find that the evaluation and assessment of the Rhizobium hasbeen limited and inadequate, lacking any convincing indication of itsecological impact in a wide-scale release," said Wendy McGoodwin,executive director of the Cambridge, Mass.-based Council forResponsible Genetics.

The EPA plans to incorporate both public and BSAC concerns intoits final risk assessment of RMB PC-2, according to agency officials.n

-- Lisa Piercey Washington Editor

(c) 1997 American Health Consultants. All rights reserved.