低温环境下野外自然好氧堆肥理化特征及微生物群落结构变化

Changes of Physico-chemical Characteristics and Microbial Community Structure During Natural Aerobic Composting Under Low Temperature Environment in the Field

[目的]研究低温环境下野外自然好氧堆肥理化特征及微生物群落结构变化,实现低温季节养殖废弃物的资源化利用。[方法]以猪粪和稻壳为原料在低温环境下进行自然好氧堆肥处理,对堆肥过程中温度、pH、含水率、NH_(4)^(+)-N、NO_(3)^(-)-N和种子发芽指数(GI)进行分析,选取细菌16S rDNA V3~V4区和真菌ITS序列进行高通量测序,比较好氧堆肥过程中不同阶段微生物群落多样性及组成差异。[结果]当环境温度为-6.7~6.4℃时,整个堆肥过程高温阶段持续11 d,经过38 d的好氧堆肥处理,堆体含水率、pH、NH_(4)^(+)-N、NO_(3)^(-)-N等指标均趋于稳定,堆肥结束时GI达到了122.12%,表明堆肥产品完全腐熟。低温条件下堆肥不同阶段样本微生物群落分析表明,Acinetobacter是堆肥初期和升温阶段优势细菌属,而Pseudofulvimonas和Ensifer在堆肥高温阶段丰度最高,Parapedobacter为堆肥末期优势细菌属。Ascobolus是堆肥初期优势真菌属,而Mycothermus为好氧堆肥升温、高温和腐熟阶段的优势菌群。细菌群落功能预测结果表明,氨基酸转运和代谢、碳水化合物运输和代谢等是堆肥过程中细菌的主要代谢功能。理化指标与微生物多样性相关性分析表明,堆肥过程中pH与属水平上丰度较高的微生物相关性强,含水率、温度、NH_(4)^(+)-N和发芽指数次之。[结论]低温条件下野外自然好氧堆肥可顺利进行并完全腐熟,这为低温环境下野外自然好氧堆肥提供了依据。

[Objective]To study the changes of physico-chemical characteristics and microbial community structure during natural aerobic composting under low temperature in the field,realize the resource utilization of breeding waste in low temperature season.[Method]Using pig manure and rice husk as raw materials for aerobic composting in the field,the temperature,pH,water content,NH_(4)^(+)-N,NO_(3)^(-)-N and germination index(GI)of seeds during composting process were analyzed,the bacterial 16S rDNA V3-V4 region and fungal ITS region were further selected for high-throughput sequencing.The diversity and composition of microbial communities in different stages of aerobic composting process were compared.[Result]When the environmental temperature was-6.7-6.4℃,the high-temperature stage of the entire composting process lasted for 11 days.After 38 days of aerobic composting treatment,the moisture content,pH,NH_(4)^(+)-N,NO_(3)^(-)-N and other indicators of the pile tended to be stable.At the end of composting,the GI reached 122.12%,indicating that the compost product was completely decomposed.The analysis of microbial communities in samples from different stages of composting under low temperature conditions showed that Acinetobacter was the dominant bacterial genus in the early and heating stages of composting,Pseudofulvimonas and Ensifer had the highest abundance in the high temperature stage of composting,and Parapedactor was the dominant bacterial genus in the late stage of composting.Ascobolus was the dominant fungal genus in the early stages of composting,while Mycothermus was the dominant microbial community in the heating,high temperature and maturation stages of aerobic composting.The predicted results of bacterial community function showed that amino acid transport and metabolism,carbohydrate transport and metabolism et al were the main metabolic functions of bacteria in composting process.The correlation analysis between physicochemical indexes and microbial diversity showed that the pH and genus abundance were highly correlated,followed by water content,temperature,NH_(4)^(+)-N and GI.[Conclusion]Natural aerobic compost can be carried out smoothly and completely decomposed in the field under low temperature conditions,it provide a basi for natural aerobic composting in the field under low temperature environment.