Title: Optimization for Enzyme Retting of Flax with Pectate Lyase Authors
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 7, 2006
Publication Date: March 8, 2007
Citation: Akin, D.E., Condon, B.D., Sohn, M., Foulk, J.A., Dodd, R.B., Rigsby, L.L. 2007. Optimization for enzyme retting of flax with pectate lyase. Industrial Crops and Products. 25:136-146. Interpretive Summary: Current retting methods result in low an inconsistent quality fiber. Early studies using commercials enzymes resulted in well-retted fiber, strength was reduced due to cellulases. Research carried out by several ARS-USDA laboratories and a university showed that the commercial product designed for scouring cotton and consisting of a pectate lyase was sufficient to ret flax without strength loss. Research resulted in an optimized protocol for retting flax from diverse sources, including linseed straw. Information is now available to commercial interests for flax fiber production that provides a flax retting protocol based on commercial enzymes and chemicals resulting in well retted, clean, and strong fiber.
Technical Abstract: Research has been undertaken to ret flax using various enzymes as a replacement for the methods used currently. Alkaline pectate lyase (PL) from the commercial product BioPrep 3000 and ethylenediaminetetraacetic acid (EDTA) from Mayoquest 200 as a calcium chelator were used in various formulations to ret flax stems. Retted stems were then mechanically cleaned through the USDA Flax Fiber Pilot Plant and passed through the Shirley Analyzer. PL and chelator effectively retted flax from both fiber flax and linseed stems, and the use of enzyme plus chelator retted flax stems better than either component alone. Fiber yield and strength were greater than that from retting with a mixed-enzyme product, which contained cellulases. Retting with PL and chelator was optimized based on fine-fiber yield, remaining shive content, and fiber properties. PL at levels of about 2 percent of the commercial product for 1 h at 55 degrees Celsius followed by treatment with 18 mM EDTA for 23-24 h at 55 degrees Celsius provided the best fibers based on these criteria. Yield and fiber properties determined by these tests were not improved with PL levels of 5 percent of the commercial product.