养猪微生物发酵床垫料细菌多样性分析

为揭示养猪微生物发酵床垫料细菌群落的多样性,明确发酵程度对垫料细菌群落结构的影响.本研究基于高通量测序技术分析了微生物发酵床3个发酵等级垫料的细菌群落特征.测序共获得1198467条序列,包括33个门、73纲、272科,600属的细菌,发酵床垫料细菌多样性与发酵等级相关.其中中度发酵垫料细菌数量最多,深度发酵垫料细菌种类最多.拟杆菌门、变形菌门、放线菌门和厚壁菌门是优势菌类群.随着发酵等级的增加,垫料中的葡萄球菌科和皮杆菌科细菌含量减少,说明发酵床可以抑制致病菌,保护养殖健康.在3个发酵阶段,微生物发酵床中起主要降解作用的细菌不同.在轻度发酵时期,黄单胞杆菌科和间孢囊菌科细菌是主要的降解菌群;在中度发酵时期,变形菌门的腐螺旋菌科、拟杆菌门的黄杆菌科、放线菌门的棒状杆菌科和异常球菌-栖热菌门的特吕珀菌科起主要降解作用;在深度发酵时期,厚壁菌门梭菌目瘤胃菌科、拟杆菌门的紫单胞杆菌科、变形菌门的产碱菌科和假单胞菌科起降解作用.随着垫料等级的增加,粪便中的指示菌——瘤胃菌含量增加,可作为垫料更换的信号.PICRUSt分析显示随着发酵等级增加,细菌代谢水平下降.本研究可为发酵床猪粪的生物降解提供理论依据,同时为发酵床垫料的管理与维护提供参考.

Bacterial diversity of litters in microbial fermentation bed for pig-raising

The main objective of this study is to investigate the bacterial communities in litters from microbial fermentation bed (MFB), and to reveal the relationship between bacterial diversity and operation time of the litters. In the light of the above considerations, diversity and dynamics of bacterial community in the MFB system were evaluated by high-throughput sequencing. A total of 1198467 sequences were obtained, containing 33 phyla, 73 classes, 272 famlies, 600 genera and 1839 OTUs (1348 shared OTUs). The bacterial community structures were related with fermentation depth. The mildly fermented litters had the highest bacterial population, while the deeply fermented litters had the highest bacterial diversity abundance. Bacteroidetes, Proteobacteria, Actinobacteria and Firmicutes were the main phyla. The population of the Families Dermabacteraceae, Microbacteriaceae, Brevibacteriaceae and Staphylococcaceae decreased with the increase of the fermentation depth, suggesting that the MFB could control pathogens to protect the health of pigs. Organics-degrading bacteria were different in the three stages of fermentation. In the mildly fermented samples, Xanthomonadaceae and Intrasporangiaceae were the main degradation bacteria, while Saprospiraceae (Proteobacteria) Flavobacteriaceae (Bacteroidetes), Corynebacteriaceae (Actinobacteria) and Trueperaceae (Deinococcus-Thermus) were the decomposers. In the deeply fermented litters, however, Ruminococcaceae (Firmicutes), Porphyromonadaceae (Bacteroidetes), Pseudomonadaceae and Alcaligenaceae (Proteobacteria) were the main decomposers. The population of the Ruminococcaceae from manure increased with fermentation, which can be a signal to replace the litters in MFB. Results of PICRUSt analysis showed that genes involved in amino acid, carbohydrate and lipid metabolism decreased as the increase of fermentation degree. Our research provides theoretical guidance for the biodegradation of pig manure and the maintenance of mattress in MFB.