| The characteristics of flora in the intestine of an animal,including the number and abundance of different microbial species and their functions,are closely related to the diets of the animal and affect the physical condition of the host.As the pangolin population is on the verge of extinction,the Malayan pangolin(Manis javanica)has been listed as a national first-class protected animal,which feeds exclusively on ants.Under the condition of rescue and captivity,it can not meet the special dietary needs,so it needs to be fed with artificial feed.In order to evaluate the digestion and absorption ability of captive Malay pangolin to feed(mainly formulated with black ant,Tenebrio molitor and cat food)and the health status of its intestinal flora after adapting to feed,this study recorded the growth and apparent digestibility of feed of five captive Malay pangolins,analyzed the diversity and community structure of fecal flora by high-throughput sequencing technology,and further screened chitin degrading strains.The main results are as follows:(1)The dominant bacterial phylum in the feces of 4 Malayan pangolins rescued at the same time are Firmicutes,Proteobacteria and Bacteroidetes,the dominant bacteria genus are Escherichia-Shigella,Clostridium sensu stricto 1,Romboutsia and Lactobacillus,the dominant fungal phylum are Ascomycota and Basidiomycota,and the dominant fungal genus are Aspergillus,Saccharomyces and Candida.(2)Bacteroides and Lactobacillus in pangolin(Mj13 and Mj18)bacterial community with fast weight growth and high feed conversion rate,Aspergillus(A.restrictus and A.penicillioides)in fungal community,and the abundance of genes related to lipid metabolism and energy metabolism is higher.(3)Pangolins(Mj22 and Mj27)with slow weight growth and low feed conversion rate have similar composition with pangolin flora with fast weight gain,but most pathogenic bacteria(Edwardsiella and Lactococcus)account for a high proportion.(4)Mj06 pangolin fecal flora alpha diversity index(bacterial ACE index,Chao1 index and Shannon index of bacteria and fungi)is the lowest.Principal component analysis(PCA)shows that its bacterial and fungal flora deviates greatly from other individuals,and the bacteria related to cellulose digestion or chitin degradation(Bacteroides,Lactobacillus,Clostridium sensu stricto and Aspergillus)account for the least,Most pathogenic bacteria(Edwardsiella and Lactococcus)account for the most,which may be the reason for the high content of chitin and low digestibility of crude fiber in feces.(5)Altogether 18 chitin-degrading microorganisms were obtained from the feces of Malayan pangolin,including 11 bacteria and 7 fungi.Among them,an-b11(Trabulsiella odontotermitis)and F05(Candida tropicalis)have obvious extracellular chitinase and strong chitin degrading ability.In conclusion,the intestinal flora plays an important role in the nutrients absorption and energy metabolism of the host adapted to the feed.Long term feeding of artificial feed may increase the proportion of harmful flora in the intestine of pangolin,and then lead to the risk of death caused by diseases such as enteritis.However,some intestinal microbiota related to chitin digestion were also found.18chitin-degrading microorganisms were isolated and cultured from feces,which provided a basis for intestinal microorganisms to assist pangolin in chitin digestion,and provided a basis for the follow-up research on pangolin rescue and probiotic additives. |
