( se farm-grown products like grain sorgh...)Bacteria are key to 'green' plastics, drugs

"We are very pleased for the opportunity to continue our collaboration with our colleagues from Rice and work to further the development and commercialization of the succinate technology," said Praveen Vadlani, principal research scientist for AgRenew. "We are excited about the prospects this project offers to meet a market need for the benefit of both institutions and American agriculture itself. We also appreciate the support of the U.S. Department of Agriculture for this work to create another high-value product from agriculture."

Many researchers are trying to create a succinate-producing bacterial mutant. They use biotechnology to either insert genes that boost succinate production or delete genes that interfere with it. The goal is to maximize the rate -- the speed of the conversion -- and the yield -- the amount of succinate produced per pound of glucose converted.

Bennett and San's bug -- known only by the designation SBS550MG -- contains an ingenious bit of metabolic engineering that allows it to produce succinate in two different ways. One method exists in wild strains of E. coli and has been modified with the deletion of four genes, each of which codes for a protein that interferes with or limits E. coli's ability to turn glucose into succinate. Bennett and San activated a second pathway and stimulated production by adding genes from lactococcus bacteria and sorghum.

Each genetic pathway metabolizes glucose and produces succinate via dissimilar chemical reactions. That means the two don't compete or interfere with one another. In fact, Bennett and San designed the paths to be complimentary, but even so, they were gratified to see how well the process worked once both paths were put in place.

"Our experiments in the laboratory have produced near-maximum yields, with almost all the glucose being converted into succinate," sai
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Source:Rice University