Study On Potential Ability Of Several Edible Fungi Biodegradation Of Lignocelluloses Of Straw

Crop straws are important renewable biological resources. Their reasonable utilization is very important to solve the problems such as food shortages, energy crisis and environmental pollution. However, under natural conditions, due to the slow decomposition of straw, the returning of straws into field will not only affect the rooting and survival of crops, but also causes inconvenience on the field management. Therefore it is urgent to develop fast straw-decomposing techniques to solve these problems mentioned above. In this paper, seven edible fungis (Pleurotus ostreatus hanhei, P. ostreatus8, P. cornucopiae, P. nebrodensis, Hypsizygus marmoreus206, Flammulina velutipes tianfu, Flammulina velutipes8802) which can grow well on the straw were chosen. Their abilities of enzyme production and lignocelluloses degradation were tested, in order to screen best strains and strain combination for improving the straw degradation. The results were as following.1、Using cellulose as the sole carbon source, P. cornucopiae, Hypsizygus marmoreus206, P. ostreatus hanhei and P. ostreatus8showed cellulose decomposition ability. P. cornucopiae, Hypsizygus marmoreus206and P. ostreatus8had the better ability to produce ligninolytic enzymes. Finally, P. ostreatus hanhei, P. ostreatus8, P. cornucopiae and Hypsizygus marmoreus206were chosen for the next study.2、The results of enzyme production in liquid and solid fermentation with rice straw as substrates showed that P. ostreatus hanhei, P. ostreatus8, P. cornucopiae and Hypsizygus marmoreus206all could product lignocellulosic enzymes. Among them Hypsizygus marmoreus206had the most activities of lignin-degrading enzymes and the Lips, Mnps and Lacs were58.52U·g-1,186.66U·g-1and8.82U·g-1, respectively. Hypsizygus marmoreus206also produced the maximal fpase activity,3.87U·mL-1. P. ostreatus hanhei had the highest activity of xylanase,41.20U·mL-1on the day16. It also displayed the maximal rice straw degradation rate (47.52%), compared to that of Hypsizygus marmoreus206(41.80%), P.ostreatus8(36.00%), P. cornucopiae (35.63%).3、When cultured on wheat straw, wheat husk and corn straw respectively, P. ostreatus hanhei, P. ostreatus8, P. cornucopiae and Hypsizygus marmoreus206showed different enzymes activities. The endo-cellulase activities from largest to smallest were5.59U·mL-1produced by Hypsizygus marmoreus206on wheat straw,4.57U·mL-1produced by P. ostreatus8on what husk,4.48U·mL-1produced by P. ostreatus hanhei on wheat straw and3.77U·mL-1produced by P. cornucopiae on wheat straw. At the same time, the fpase activity of P. cornucopiae, P. ostreatus8, Hypsizygus marmoreus206and P. ostreatus hanhei were12.22U·mL-1(Wheat husk fermentation,11.18U·mL-1(wheat husk fermentation),9.87U·mL-1(wheat straw fermentation),9.21U·mL-1(corn stover fermentation), respectively. The largest xylanase activity of P. cornucopiae, P. ostreatus8, Hypsizygus marmoreus206and P. ostreatus hanhei were69.52U·mL-1(wheat husk fermentation),62.15U·mL-1(wheat husk fermentation),37.79U·mL-1(Wheat husk fermentation),31.73U·mL-1(corn stover fermentation), respectively.During solid fermentation, the largest activity of Lip, Mnp and Lac produced by Hypsizygus marmoreus206were66.66U·g-1(wheat husk fermentation),74.03U·g-1(wheat husk fermentation) and19.85U·g-1(wheat husk fermentation), respectively.4、The fermentation result using rice straw as substrate showed that all the strains combination could produce more extracellular lignocellulosic enzymes than single strain. The highest lignin enzymes activities and staw degradation rate were observed in combination of Hypsizygus marmoreus206and P. ostreatus hanhei.