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

have something to do with the evolutionary selection of fish to live in water. In general, amy- lase activity in fish follows the pattern of carnivorous fish < omnivorous fish < herbivorous fish [66]. We speculated that Microbacterium foliorum is most likely produce some cold-active α-amylases in this special environment to promote starch digestion in the intestines. In addi- tion, as a unique bacterial species recovered from the guts of tilapia in the fermented FM group, Bacillus aquimaris could also produce α-amylase [67]. It should be noted that although woody forage has certain resource advantages, it is difficult for fish to degrade the lignin and cellulose in this material. However, the bacteria in guts of fish could assist in this process. For Table 5. Antibacterial activity of aerobic culturable bacteria isolated from tilapia gut. Bacterial representative isolates Diameter of the growth inhibition zone (mm) SA SI ML VP Bacillus altitudinis (MK281515) 13.1±0.5 11.3±0.2 15.3±0.6 - Bacillus amyloliquefaciens (MK281516) 15.5±0.9 17.1±0.7 13.3±0.6 12.3±0.6 Bacillus anthracis (MK281517) - - - - Bacillus aquimaris (MK281518) - - - - Bacillus baekryungensis (MK281519) - - - - Bacillus cereus (MK281520) - - 12.3±0.4 Bacillus cibi (MK281521) - 9.3±0.3 - - Bacillus infantis (MK281522) - - - - Bacillus marisflavi (MK281523) - - - - Bacillus megaterium (MK281524) - - - - Bacillus pumilus (MK281525) 12.4±0.9 10.2±0.4 16.2±0.5 Bacillus sp. (MK281526) - - - - Bacillus stratosphericus (MK281527) - - 11.2±0.5 -

Bacillus subterraneus (MK281528) - - - Bacillus subtilis (MK281529) 12.3±0.5 - - - Bacillus thioparans (MK281530) - - - - Bacillus thuringiensis (MK281531) - - - - Bacillus vietnamensis (MK281532) - - - - Fictibacillus rigui (MK281533) - - 9.2±0.8 - Lysinibacillus fusiformis (MK281534) - - - - Lysinibacillus mangiferihumi (MK281535) 9.6±0.5 12.5±0.6 - - Lysinibacillus sphaericus (MK281536) - - - - Microbacterium foliorum (MK281537) - - - - Proteus mirabilis (MK281538) - - 13.5±0.7 - Pseudomonas fulva (MK281539) - - - - Pseudomonas sp. (MK281540) 9.6±0.3 11.5±0.6 - - Rhodococcus sp. (MK281541) - - - - Rummeliibacillu spycnus (MK281542) - - - - Staphylococcus epidermidis (MK281543) 14.4±0.6 - 12.2±0.3 - Staphylococcus pasteuri (MK281544) - - - - Staphylococcus sp. (MK281545) - - - 15.2±0.7 Stenotrophomonas maltophilia (MK281546) 12.5±0.7 8.4±0.7 13.2±0.3 - Streptomyces albogriseolus (MK281547) - - - - Streptomyces rutgersensis (MK281548) 13.5±0.8 11.4±0.6 17.2±0.2 14.9±0.8 Thalassospira sp. (MK281549) - - - - SA Streptococcus agalactiae, SI Streptococcus iniae, ML Micrococcus luteus, VP Vibrio Parahemolyticus,—displayed traces or no antagonistic effects were observed https://doi.org/10.1371/journal.pone.0235560.t005 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 12 / 17