Effects of woody forages on biodiversity and bioactivity of aerobic culturable gut bacteria of tilapia (Oreochromis niloticus)

plant protein and the resulting intestinal microbes and functions. The present study investi- gated for the first time that the gut bacterial communities of tilapia changed greatly after feed- ing woody forages, including MOL, fermented MOL, FM and fermented FM. Furthermore, some unique bacterial communities were found in the guts of tilapia in this study. Our results expand the knowledge and understanding of the gut bacterial diversity of tilapia. In this study, 133 aerobic culturable isolates were recovered and identified from the gut of tilapia from the five forage groups, with 35 species and 12 genera in three phyla (Firmicutes, Actinobacteria and Proteobacteria) identified. These results suggested that the guts of tilapia harbor abundant and diverse bacterial communities. Pakingking et al. [56] reported that 13 genera, including Aeromonas, Bacillus, Citrobacter, Edwardsiella, Enterobacter, Klebsiella, Table 2. The situation of the identified and known bacteria in three different media. Bacterial species (the representative isolates’ accession numbers in GenBank) MRS LB PIYCA Bacillus altitudinis (MK281515) 1 3 5 Bacillus amyloliquefaciens (MK281516) 1 Bacillus anthracis (MK281517) 1 Bacillus aquimaris (MK281518) 5 2 Bacillus baekryungensis (MK281519) 2 Bacillus cereus (MK281520) 2 1 Bacillus cibi (MK281521) 2 Bacillus infantis (MK281522) 7 2 Bacillus marisflavi (MK281523) 1 Bacillus megaterium (MK281524) 7 1 Bacillus pumilus (MK281525) 1 1 Bacillus sp. (MK281526) 4 2 2 Bacillus stratosphericus (MK281527) 2 1 Bacillus subterraneus (MK281528) 2

Bacillus subtilis (MK281529) 1 1 Bacillus thioparans (MK281530) 3 Bacillus thuringiensis (MK281531) 1 Bacillus vietnamensis (MK281532) 2 Fictibacillus rigui (MK281533) 1 Lysinibacillus fusiformis (MK281534) 3 Lysinibacillus mangiferihumi (MK281535) 2 1 Lysinibacillus sphaericus (MK281536) 3 Microbacterium foliorum (MK281537) 1 Proteus mirabilis (MK281538) 5 11 3 Pseudomonas fulva (MK281539) 1 Pseudomonas sp. (MK281540) 3 8 2 Rhodococcus sp. (MK281541) 1 Rummeliibacillus sp. (MK281542) 1 Staphylococcus epidermidis (MK281543) 2 Staphylococcus pasteuri (MK281544) 2 Staphylococcus sp. (MK281545) 1 1 Stenotrophomonas maltophilia (MK281546) 1 2 Streptomyces albogriseolus (MK281547) 1 Streptomyces rutgersensis (MK281548) 1 Thalassospira sp. (MK281549) 2 3 Total number of bacterial isolates 27 70 31 https://doi.org/10.1371/journal.pone.0235560.t002 PLOS ONE Effects of wood forages on gut bacterial biodiversity and bioactivity in tilapia PLOS ONE | https://doi.org/10.1371/journal.pone.0235560 July 2, 2020 9 / 17