秸秆垫料的猪粪异位发酵床微生物群落分析

为了解秸秆垫料对生猪异位发酵床发酵过程的影响,明确不同垫料的微生物群落演替,分别以油菜秸秆+木屑+砻糠为Y组、水稻秸秆+木屑+砻糠为S组及木屑+砻糠为CK组,以对不同垫料组合进行异位发酵床试验,收集不同发酵阶段的垫料样品,进行理化指标的测定和Illumina高通量测序。结果显示,CK组的微生物多样性要明显低于S组和Y组。发酵进程中不同垫料的微生物演替趋势相似,变形菌门的相对丰度都呈下降趋势,但CK组降低了75%,S组和Y组则分别降低了38.0%和23.2%。不同处理发酵床嗜温期主要微生物有芽孢杆菌属、乳杆菌属、鞘铵醇杆菌属、假单胞菌属等,但微生物的丰度存在差异。同时,功能基因预测显示脂类、氨基酸和碳水化合物代谢相关基因拷贝数Y组最高。不同处理在发酵进程中的理化指标变化相似,但Y组垫料的升温速率更快且整体温度更高,同时可溶性氮的含量更高。研究表明,秸秆垫料组的微生物丰富度和多样性都要高于对照组,同时油菜秸秆组的微生物有机质相关代谢更加活跃,更有利于发酵床的高温运行和有机肥形成。

Analysis of the microbial community of pig manure fermented with straw litter in an ectopic fermentation system

The objective of this study was to explore the effect of different straws on the fermentation process of pig manure in an ectopic fermentation system(EFS)and to reveal the succession of microbial communities on different straws. Three types of litter were used in this experiment. Group Y was composed of rapeseed straw, wood chips, and rice chaff; group S was composed of rice straw, wood chips, and rice chaff; and group CK was composed of wood chips and rice chaff. Litter samples were collected at different times during the EFS process to analyze the physicochemical properties and conduct Illumina high-throughput sequencing. The results showed that the microbial diversity in group CK was significantly lower than those of groups S and Y. The trend of microbial succession was similar in all vessels during the EFS process, but the degree of change varied considerably. The abundance of Proteobacteria in group CK decreased by 75.0%, while those in group S and group Y decreased by 38.0% and 23.2%, respectively. The dominant microorganisms in the thermophilic period of the three treatments were Bacillus, Lactobacillus, Sphingobacterium, and Pseudomonas, but their abundance varied. Gene prediction and functional analysis indicated that the abundances of lipid, amino acid, and carbohydrate metabolism-related genes in group Y were the highest. The changes in the dynamics of physicochemical indexes in all treatments were similar in the fermentation process, but the heating rate, overall temperature, and dissolved N concentration of group Y were the highest. The results suggested that the addition of straw to litter increased the microbial richness and diversity in the EFS. Meanwhile, rapeseed straw made the organic matter metabolism more active and contributed to high-temperature operation of the EFS and the formation of organic fertilizer.