Open AccessEffects of woody forages on biodiversity and bioactivity of aerobic culturable gut bacteria of tilapia (Oreochromis niloticus)
Author(s) -
Feng Wu,
Biao Chen,
Sha Liu,
Xiongjian Xia,
Liu-Ling Gao,
Xiaoyong Zhang,
Qin Pan
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0235560
Subject(s) - biology , streptococcus iniae , tilapia , firmicutes , oreochromis , bacillus pumilus , microbiology and biotechnology , bacillus (shape) , bacteria , vibrio , aerobic bacteria , actinobacteria , probiotic , streptococcus agalactiae , food science , streptococcus , 16s ribosomal rna , genetics , fishery , fish <actinopterygii>
The present study investigated the effects of four woody forages ( Moringa oleifera Lam (MOL), fermented MOL, Folium mori (FM) and fermented FM) on biodiversity and bioactivity of aerobic culturable gut bacteria of tilapia ( Oreochromis niloticus ) by a traditional culture-dependent method. A total of 133 aerobic culturable isolates were recovered and identified from the gut of tilapia, belonging to 35 species of 12 genera in three bacterial phyla (Firmicutes, Actinobacteria and Proteobacteria). Among them, 6 bacterial isolates of Bacillus baekryungensis , Bacillus marisflavi , Bacillus pumilus , Bacillus methylotrophicus , Proteus mirabilis and Pseudomonas taiwanensis were isolated from all the five experimental groups. The Bray-Curtis analysis showed that the bacterial communities among the five groups displayed obvious differences. In addition, this result of bioactivity showed that approximate 43% of the aerobic culturable gut bacteria of tilapia displayed a distinct anti-bacterial activity against at least one of four fish pathogens Streptococcus agalactiae , Streptococcus iniae , Micrococcus luteus and Vibrio parahemolyticus . Furthermore, Bacillus amyloliquefaciens and Streptomyces rutgersensis displayed strong activity against all four indicator bacteria. These results contribute to our understanding of the intestinal bacterial diversity of tilapia when fed with woody forages and how certain antimicrobial bacteria flourished under such diets. This can aid in the further exploitation of new diets and probiotic sources in aquaculture.