低温菌强化堆肥起爆进程中细菌群落响应机制

Mechanisms of bacterial community response to hypothermia-enhanced compost start-up process

为探讨低温菌强化冬季堆肥起爆细菌群落响应机制,确保北方冬季有机垃圾堆肥的快速启动,开展低温菌强化畜禽粪便堆肥快速起爆试验,结合16S rRNA扩增子测序技术及生物信息学分析方法,明确堆体温度、微生境因子及微生物特性等指标变化,挖掘生物强化低温菌在畜禽粪便堆肥起爆进程中的作用,探明堆肥进程细菌群落响应机制。结果表明:接种低温菌处理(CT)的堆体温度在18 h时迅速升高至20.0℃,快速通过起爆期,此时未接菌(CK)组的温度仅为15.8℃。CT组温度在36 h超过50.0℃。整个过程中未接种低温菌的处理组并没有完成堆肥快速启动。CT组有机组分快速分解,为堆肥温度升高提供了充足的热能。由群落丰度变化可知,低温菌属于促进细菌群落改变的生物标志物(Biomarker),接种低温菌可激活堆肥起爆进程中细菌群落结构的演变。此外,方差分解分析结果表明,低温菌、理化指标及细菌群落的交互作用是堆肥温度变化的主导因素,可通过增加低温菌丰度调控堆肥起爆进程中的温度变化。

The response mechanisms of psychrophiles to enhance the bacterial community in northern winter organic waste composting and ensure rapid start-up of organic waste composting in cold environments was explored.This study conducted a rapid start-up experiment of livestock manure compost enhanced by psychrophiles.Moreover,combined with 16S rRNA amplicon sequencing technology and bioinformatics analysis methods,changes in piles temperature,microhabitat factors,and microbial characteristics were determined to explore the role of bio-enhanced psychrophiles in the start-up process of livestock manure compost and to investigate the microbial response mechanism of the composting process.The results showed that the temperature of the piles inoculated with the inoculation treatment(CT)rose rapidly to 20.0℃at 18 h and quickly crossed the start-up period when the temperature of the uninoculated control(CK)group was only 15.8℃.The temperature in the CT group exceeded 50.0℃at 36 h.The treatment group that was not inoculated with psychrophiles could not complete the rapid start-up of the composting.Moreover,the rapid decomposition of organic fractions in the CT group provided sufficient thermal energy for the increase in composting temperature.It was clear from the changes in community abundance that psychrophiles were biomarkers that promote changes in bacterial communities and that inoculation with psychrophiles activated the evolution of bacterial community structure during compost start-up.In addition,the results of the variance partitioning analysis showed that the interaction of psychrophiles,physicochemical indicators,and bacterial communities were the dominant factors in the temperature variation of the compost and that the temperature variation of the compost start-up process could be regulated by increasing the abundance of psychrophiles.