复合抗菌肽对山羊瘤胃菌群结构的影响

摘要

试验旨在探讨复合抗菌肽对山羊瘤胃菌群结构的影响,以期为抗菌肽应用于反刍动物提供理论依据.选取24只4月龄川中黑山羊,分为4组,每组6只,正常精料组(A),正常精料+抗菌肽组(C),双倍精料组(D),双倍精料+抗菌肽组(E)分别饲喂精料300、300、600和600 g·d-1·只-1,C与E组饲喂3 g·d-1·只-1复合抗菌肽.于21 d晨饲前每组随机选取3只采集瘤胃液,提取样品总DNA,扩增16S rRNA V4区,扩增产物采用Miseq平台测序.结果表明:1)共获得高质量序列629634条,97%相似度下聚类后共获得13227个OTU.2)所得OTU经物种注释后,门水平上,除D组最优势菌门为厚壁菌门(Firmicutes)(34.30%)外,其余各组最优势菌门均为拟杆菌门(Bacteroidetes)(38.52%~43.68%),且添加复合抗菌肽显著降低变形菌门(Proteobacteria)与螺旋菌门(Spirochaetes)含量(P0.05);增加精料量显著增加普雷沃菌属、密螺旋体等含量(P0.05).表明添加复合抗菌肽降低变形菌门和螺旋菌门的相对含量,提高部分降解纤维菌属的含量;增加精料量可增加厚壁菌门和螺旋菌门相对含量,降低拟杆菌门和变形菌门的相对含量,增加普雷沃菌属相对含量,降低琥珀酸弧菌属相对含量;瘤胃细菌多样性并不受复合抗菌肽及精料量的影响.%The aim of this study was to evaluate the effects of composite antimicrobial peptide ( AMP) on rumen bac-teria community structure by MiSeq high throughput sequencing technology, which could provide theoretical basis for the application of antimicrobial peptide in ruminant. Twenty-four male goats (4-month-old) were randomly divided into 4 groups according to the similar weight. Four groups were normal concentrate group A ( concentrate 300 g·d-1· goat-1 ) , normal concentrate+AMP group C ( concentrate 300 g·d-1·goat-1 + AMP 3 g·d-1·goat-1 ) , double con-centrate group D ( concentrate 600 g·d-1·goat-1 ) , double concentrate + AMP group E ( concentrate 600 g·d-1· goat-1 + AMP 3 g·d-1·goat-1 ) . The rumen fluid samples were collected after 20 d, and then the total DNA were extraced for amplification 16S rRNA(520F-802R), sequencing by MiSeq Illumina250. Results showed as follows:1) A total of 629634 valid 16S rDNA sequences and 13227 operational taxonomic unit ( OTU) across 12 samples were obtained. 2) At phylum level, Bacteroidetes was the most abundant phyla in A, C and E groups (38. 52% -43. 68%) , except for the D group ( Firmicutes was the most abundant phyla, 34. 30%) , and Proteobacteria and Spirochaetes were significantly decreased when adding AMP ( P0. 05). Prevotella and Treponema were significantly increased in D group compared with A group (P0. 05) between groups on alpha diversity index (Chao, ACE, Shannon and Simp-son). In conclusion, Proteobacteria and Spirochaetes were decreased when adding complex antibacterial peptide, while some genus of cellulolytic were increased;Firmicutes and Spirochaetes were increased when the amount of concentrate changed from 300 to 600 g·d-1·goat-1 , while Bacteroidetes and Proteobacteria were decreased, and Prevotella was in-creased, while Succinivibrio was decreased. Moreover alpha diversity index was not affected by complex antibacterial peptide or the amount of concentrate changed from 300 to 600 g·d-1·goat-1 .