黑鲷(Acanthopagrus schlegelii)肠道细菌群落对饲料中添加不同羽毛粉的响应

羽毛粉是一种潜在的饲料蛋白源。在水产动物饲料中添加适量的羽毛粉,不仅可以降低饲料成本,而且有助于禽类废弃物的再利用。在动物消化、降解、吸收羽毛粉过程中,动物肠道中的微生物可能发挥着重要作用;添加羽毛粉的饲料对鱼类肠道微生物多样性与群落结构的影响目前还不清楚。基于细菌16SrRNA基因高通量测序,作者对比研究了以添加羽毛粉(包括水解、酸解、膨化处理或生羽毛粉实验组,添加量为5%)和不添加羽毛粉的饲料(即对照组,包括鱼粉和商业饲料两组)喂养黑鲷12周后,黑鲷肠道细菌多样性与群落结构的变化情况。统计分析结果表明:添加羽毛粉的实验组中肠道细菌的丰富度、辛普森指数和香农指数显著低于对照组(P0.05);不含酸解羽毛粉组的实验组,其细菌群落结构与对照组差异显著(P0.05)。总体来看,黑鲷肠道细菌主要由厚壁菌门(57.3%)和变形菌门(36.3%)组成;实验组细菌群落中拟杆菌纲、梭菌纲、δ-变形菌纲、草酸杆菌科和青枯菌属的相对丰度显著低于对照组。不同的羽毛粉处理组之间也呈现出群落结构上的差异:与水解羽毛粉组相比,生羽毛粉组的变形菌门、γ-变形菌门、海洋螺菌目、盐单胞菌科和盐单胞菌属的相对丰度显著下降;与鱼粉组相比,生羽毛粉组中芽孢杆菌目在群落中的占比显著上升,而拟杆菌门、草酸杆菌科和青枯菌属的占比则显著下降,而且生羽毛粉组中厚壁菌门与变形菌门相对丰度的比值(7.42)明显高于鱼粉组(0.97)和水解羽毛粉组(0.74)且均接近显著(P=0.057)。与鱼粉组相比,水解羽毛粉组中紫单胞菌科和回线属的相对丰度显著下降,而盐单胞菌属的相对丰度显著上升。

RESPONSE OF GUT BACTERIAL COMMUNITY IN BLACK SEA BREAM TO DIFFERENT FEATHER MEAL IN FEED

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.