Soybeans a source of valuable chemical

The humble soybean could become an inexpensive new source of a widely used chemical for plastics, textiles, drugs, solvents and as a food additive.

Succinic acid, traditionally drawn from petroleum, is one focus of research by Rice chemists George Bennett and Ka-Yiu San. In 2004, the Department of Energy named succinic acid one of 12 ''platform'' chemicals that could be produced from sugars by biological means and turned into high-value materials.

Several years ago, Rice patented a process by Bennett and San for the bio-based production of succinic acid that employed genetically modified E. coli bacteria to convert glucose into succinic acid in a way that would be competitive with petroleum-based production.

The new succinate process developed by Bennett, San and Chandresh Thakker and reported recently in Bioresource Technology promises to make even better use of a cheap and plentiful feedstock, primarily the indigestible parts of the soybean.

''We are trying to find a cheaper, renewable raw material to start with so the end product will be more profitable,'' said Thakker, a research scientist in the Bennett lab at Rice's BioScience Research Collaborative and lead author of the study. ''The challenge has been to make this biomass process cost-competitive with the petrochemical methods people have been using for many years.''

Bennett feels they have done that with soybean-derived feedstock as an inexpensive source of the carbon that microorganisms digest to produce the desired chemical via fermentation. ''A lot of people use plant oils for cooking – corn or soybean or canola - instead of lard, as they did in the old days,'' he said. ''The oils are among the main products of these seeds. Another product is protein, which is used as a high-quality food.