Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2015
Publication Date: 12/1/2015
Publication URL: http://handle.nal.usda.gov/10113/63249
Citation: Harry-O'kuru, R.E., Gordon, S.H., Klokkenga, M. 2015. Bio-generation of succinic acid by fermentation of Physaria fendleri seed polysaccharides. Industrial Crops and Products. 77:116-122.
Interpretive Summary: The NCAUR Bio-Oils Research Unit pilot plant annually produces large quantities of seed meals from oilseed crushes in order to express the oil. About 70% of the crushed seed is usually left as presscake, which may be used as animal feed because of the protein and carbohydrate content. However, many seeds contain materials unsuitable as feed in spite of their protein content. Such antinutritional presscake ends up in landfills. Lesquerella presscake is in this category. This project explores the possibile utilization of Lesquerella presscake or waste as renewable feedstock for producing an important value-added product, succinic acid. The work reported here shows the feasibility of converting the waste material into the value-added product, succinic acid. Thus, instead of heading to the landfill, the waste agricultural byproduct, i.e. the oilseed presscake, can become a renewable feedstock for producing valuable new products that are presently produced mainly from petroleum sources.
Technical Abstract: The Bio-Oils Research unit at the National Center for Agricultural Utilization Research in Peoria, Illinois, produces over 70% of crushed oilseed as press cake annually as tons of seed are crushed for oil. A large amount of this press cake cannot be used as animal feed because of anti-nutritional properties and generally winds up landfilled. Lesquerella fendleri now reclassified as Physaria fendleri and its press cake belongs in this category of oilseed processed here and its meal is unsuitable as animal feed. Hence the purpose of this study was to explore use of its press cake, especially its polysaccharide content as renewable substrate for fermentative production of succinic acid when the crop is commercialized. Success with P. fendleri would lead to utilization of similar oilseed press cakes. Succinic acid, an important platform chemical is mainly produced industrially from maleic anhydride, a petrochemical intermediate as substrate. But because most research in succinic acid fermentative production is based on glucose, our goal here was to explore expansion of sugar substrate use beyond glucose so the polysaccharides from oilseed crushes could become renewable feedstuff for succinic acid production. Our initial trials found that the ruminal microorganism strain Actinobacillus succinogenes DSM 22,257 was capable of producing succinate using standard sugars known to be components of P. fendleri polysaccharides, i.e., glucose, arabinose, galactose, galacturonic acid and xylose. Subsequent trials with hydrolyzates of P. fendleri press cake using this strain successfully produced succinate at 93 to >98% conversion. The succinic acid produced was readily quantitatively recovered by solvent extraction of the heterogenous fermentation broth. The crude extract was purified by recrystallization to >99% purity.