(1) 中山大学海洋科学学院

Feather meal is a potential protein source of high nutritional value. Adding a moderate amount of feather meal into animal feed not only reduces the cost for feed but also helps re-utilizing wastes. The microbial community in the animal gut may be functionally adapted to available resources, thus play an important role in degradation and absorption of feather meal. However, little is known about the effect of feather meal amendment on the diversity and community structure of intestinal microbes in mariculture. We investigated the influence of the feather-amended meal(5%)on gut bacteria of black sea bream(Acanthopagrus schlegelii). Before adding to the meal, feather was hydrolyzed(FH),acid-treated(FA), puffed(FP), or used as raw feed(FO). Fish meal(FN)and commercially-sold feed(FS)were taken as the control. After feeding for 12 weeks, the gut bacterial diversity and communities were assessed using 16S rRNA high throughput sequencing. In general, the feather-amended treatments had significantly lower bacterial alpha diversities(OTU richness, Simpson and Shannon indices), and significantly different community structure, compared with the control. The relative abundances of Bacteroidia, Clostridia, Deltaproteobacteria, Oxalobacteraceae, and Ralstonia were significantly lower in the feather-amended treatments than in the control. There were also differences between feather-amended treatments of various styles:the proportions of Proteobacteria, Gammaproteobacteria, Oceanospirillales, Halomonadaceae,and Halomonas in the FO treatment were significantly lower than that in the FH; the proportion of Bacillales in the FO was significantly higher than that in the FN, while the proportions of Bacteroidetes, Oxalobacteraceae and Ralstonia were significantly lower. In addition, The FO treatment tended to have a higher abundance ratio of Firmicutes to Proteobacteria(7.42)than the FN(0.97)and FH(0.74). The proportions of Porphyromonadaceae and Treponema in the FN treatment were significantly higher than that in the FH. Nevertheless, Halomonas appeared to be much lower in the FN than in the FH.