| Bamboo industry is the dominant industry of modern forestry in China,but the accumulation of a large number of refractory mulch in the process of bamboo cover management leads to soil degradation,bamboo shoot production,and a significant decline in economic income.it is urgent to solve this problem to promote industrial development.In this paper,we isolated endophytic fungi from Phyllostachys violascens 、Phyllostachys edulis‘Pachyloen’、Phyllostachys Prominens by using tissue block method and analyzed the diversity of the fungi in different shoot-producing bamboo;guaiacol and aniline blue were used to screen lignin-degrading fungal strain.Optimizing the enzymatic conditions of the strain and exploring the degradation effects of lignin,main research results as follows:(1)191 strains of endophytic fungi were isolated from three shoot-producing bamboo species,and identified into 20 taxa by molecular phylogenetic analysis;The diversity of endophytic fungi communities was different among different shoot-producing bamboo species and their tissue parts,with host specificity and tissue preference;The diversity index and evenness of endophytic fungi of different shoot-producing bamboo species is Phyllostachys violascens(29)Phyllostachys edulis‘Pachyloen’(29)Phyllostachys Prominens;The diversity index of endophytic fungi of Phyllostachys violascens and Phyllostachys Prominens showed that the leaf(29)root(29)stem,but The diversity index of endophytic fungi of Phyllostachys edulis‘Pachyloen’showed that the leaf(29)stem(29)root.(2)Ten lignin-degrading fungi were initially screened by the reaction of guaiacol plate and aniline blue plate;Combined with enzyme activity determination,a highly efficient lignin-degrading strain LY26 was screened out,with a lignin degradation rate of28.85%.(3)The fermentation conditions of LY26 strain were optimized by single factor experiment.The results showed that the optimal carbon source of LY26 strain was alkali lignin with a concentration of 2%,the optimal nitrogen source of LY26 strain was yeast powder with a concentration of 2%,The optimum culture time was 108 h,the optimum culture temperature was 25,and the optimum p H was 6.0,The optimized enzyme activities of LY26 laccase and manganese peroxidase could be reached 143.44U/m L、266.24U/m L.(4)The degradation characteristics of LY26 on grain hulls were explored through indoor fermentation experiment.The results prove that LY26 can not only degrade lignin in grain hulls effectively,but also degrade cellulose to some extent,compared with the control,the lignin content of treatment group decreased by 22.44%;After treated by strain LY26,Observed by scanning electron microscope many cracks and cavities appeared on the surface of grain hulls.These results indicated that the strain could degrade grain hulls effectively and change the surface microstructure of grain hulls. |
