Establishment Of Fungi Consortium For Anaerobic Bioconversion Of Crop Residues And Its Enzymatic Characteristics

Biomass resources, which are renewable and friendly to environmental, have greatpotential value. Crops straw contains large quanties of lignocellulose, which is themost abundant biomass resource in the earth. If we can make an effective use of theseresources, it will benefit to solve problems of the energy shortage.It has been proved that ruminant could degrade cellulose effectively since manyyears ago. Rumen microorganisms contribute to dgradation of lignocellulose. In fact,rumen anaerobic fungus play a very significant role on degradation of lignocellulosicmaterials.In this study, an anaerobic fungi consortium was built from rumen and futher wasstudied its fiber digestibility and enzymes features. Through the study, we get theconclusions as follow:（1） An rumen fungi consortium was established by using straw power as the solecarbon source under anaerobic condition.（2） Detected the enzymes activities of the fermentation supernatant,we found that thehighest activities of carboxyl methyl cellulose enzyme, microcrystalline celluloseenzyme, xylanase, feruloyl esterase and acetyl esterase are3.31U/mL,27.43U/mL,7.40U/mL,2.20mU/mL and0.75U/mL, respectively.（3） Characterizations of feruloyl esterase（FAE） and acetyl esterase（AE） were studied.The optimum pH and temperature of FAE were8.0and40℃.It was significantlyinhibited by Fe²⁺, Cu²⁺, Fe³⁺and activated by Mg²⁺. The optimum pH andtemperature of AE were8.0and45℃. It was significantly inhibited by Fe³⁺ andactivated by Mg²⁺, K⁺.（4） Feruloyl esterase and acetyl esterase were separated and purified by ammoniumsulfate precipitation, DEAE-Cellulose ion-exchange chromatography, andSephadex G-75gel filtration,respectively. The Feruloyl esterase was purified8.76fold and had a recovery of15.8%. The acetyl esterase was purified5.29fold witha recovery of31.6%. （5） The study of the ability to degrade the straw lignocelluloses showed that thedegradation rates of cellulose and hemicellulose were up to24.56%and31.71%,respectively. The highest concentration of reducing sugar was0.64mg/mL.（6） Lignin can be isolated from crop residues by the fungi consortium.