Hydrolysis of Plant Cell Wall of Eucommia ulmoides by Cellulase and Extraction of Long Silk Gum

The current major methods for extracting Eucommia ulmoides gum require that Eucommia ulmoides leaf and bark be pulverized prior to gum extraction,which,hence,lead the elasticity,malleability and tensile strength to reduce.To extract long silk gutta percha,this paper investigated the hydrolysis of plant cell wall of Eucommia ulmoides by cellulase,the removal of cuticle layer on Eucommia ulmoides leaf and the extraction of long silk gum.It was found that 1% NaOH at 70 ℃ efficiently degraded the cuticle layer from E.ulmoides leaf,which prevented cellulase to touch and hydrolyze cell wall of fiber.Petroleum ether (60-90 ℃) is an ideal solvent to extract E.ulmoides gum.Cellulase hydrolyzed cellulose cell wall effectively at 50 ℃ and pH 4.Thus permeability of cell wall increased and E.ulmoides gum with long silk was easy to dissolve into petroleum ether and the yield increased from original 2.5% to over 3%.The tensile strength of obtained gutta percha increased from 0.02 MPa of milled E.ulmoides leaf to 60.5 MPa,breakage-extensibility from about 0% to 24% and tearing strength from 0.5 to 36 kN/m.Activated carbon can well adsorb nature compounds from E.ulmoides leaf and bark that dissolve in petroleum,promoting the dissolving capacity of used petroleum ether in recycle.