title: The gut microbiome and degradation enzyme activity of wild freshwater fishes influenced by their trophic levels.
abstract: Vertebrate gut microbiome often underpins the metabolic capability and provides many beneficial effects on their hosts. However, little was known about how host trophic level influences fish gut microbiota and metabolic activity. In this study, more than 985,000 quality-filtered sequences from 24 16S rRNA libraries were obtained and the results revealed distinct compositions and diversities of gut microbiota in four trophic categories. PCoA test showed that gut bacterial communities of carnivorous and herbivorous fishes formed distinctly different clusters in PCoA space. Although fish in different trophic levels shared a large size of OTUs comprising a core microbiota community, at the genus level a strong distinction existed. Cellulose-degrading bacteria Clostridium, Citrobacter and Leptotrichia were dominant in the herbivorous, while Cetobacterium and protease-producing bacteria Halomonas were dominant in the carnivorous. PICRUSt predictions of metagenome function revealed that fishes in different trophic levels affected the metabolic capacity of their gut microbiota. Moreover, cellulase and amylase activities in herbivorous fishes were significantly higher than in the carnivorous, while trypsin activity in the carnivorous was much higher than in the herbivorous. These results indicated that host trophic level influenced the structure and composition of gut microbiota, metabolic capacity and gut content enzyme activity.
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Han
authors.initials: H
authors.lastname: Liu
authors.affiliation: Laboratorio de Biotecnología Genómica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Boulevard del Maestro esquina Elías Piña, Colonia Narciso Mendoza, Ciudad Reynosa, 88710, Tamaulipas, Mexico.
authors.forename: Xianwu
authors.initials: X
authors.lastname: Guo
authors.affiliation: Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand.
authors.forename: Ravi
authors.initials: R
authors.lastname: Gooneratne
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Ruifang
authors.initials: R
authors.lastname: Lai
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Cong
authors.initials: C
authors.lastname: Zeng
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Fanbin
authors.initials: F
authors.lastname: Zhan
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, P. R. China.|Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Changde 41500, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Wang
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D005399:Fishes / Q000382:microbiology*; D005618:Fresh Water; D007422:Intestines / Q000201:enzymology / Q000382:microbiology*; D064307:Microbiota; D013045:Species Specificity