Screening And Identification Of Pepper Straw Lignin-degrading Bacteria And Its Feeding Effect

In recent years,with the continuous expansion of pepper planting area in Guizhou Province,a large number of waste pepper stalks have been produced,and the burning of pepper stalks and its environmental problems have attracted wide attention.Pepper straw is an important measure to utilize straw resources and increase the source of new forage when it is used as roughage.However,pepper straw contains high lignocellulose content and is difficult to be used,which limits its popularization and application.Therefore,it is of great significance to screen safe and efficient pepper straw degrading bacteria and clarify its degradation effect for straw feeding and improving resource utilization.This study isolated from chili straw decay and pine wood filter can effectively degrade lignin strains,using solid state fermentation technology to deal with chili straw,feeding experiment was used to study in the broiler diet at the same time to add a certain amount of fermented pepper straw,discuss the antioxidant ability of poultry production performance and the influence of the intestinal microbial flora,It provides a new idea for the exploitation of pepper straw as a new roughage resource and the biological harmless treatment of pepper straw.The results of this study show that:1.25 strains of single strains with strong growth ability were isolated and purified from pepper straw,including 18 strains of bacteria and 7 strains of fungi,15 strains of pine rot wood,10 strains of bacteria and 5 strains of fungi.A total of 16 strains produced chromogenic circles on PDA-guaiacol medium,and the strains with high laccase production activity,namely CB3,CF2 and PF1,were screened.2.Considering the level of laccase activity and the degradation rates of lignin,cellulose and hemicellulose,strain CB3 was the optimal target strain,and reached the first peak of enzyme activity on the 20 th day of degradation culture.Based on morphological observation and homology analysis of all strains,strain CB3 was identified as Bacillus subtilis.3.The feeding results of broilers showed that dietary supplemented with 2%fermented pepper straw significantly increased the daily gain and GSH-PX content of broilers,significantly decreased the MDA content,and improved the antioxidant capacity of broilers.4.Microbial diversity: When broilers were fed with fermented pepper straw,the dominant phyla in the cecum of broilers were Bacteroidetes and Firmicutes,respectively.The dominant bacteria genera were Bacteroidetes and Alistipes.The relative abundance of Tenericutes and Elusimicrobia were significantly decreased,while the relative abundance of Bacteroidetes and Faecalibacterium were significantly increased.In conclusion,Bacillus subtilis screened from the experiment has good ability to degrade lignin;The addition of fermented pepper straw in the basic diet of broilers significantly improved the growth performance,intestinal microflora and immune function of broilers,and provided reference for the feed application of pepper straw.