基于强化推流工艺(PFR)的餐厨垃圾堆肥微生物群落结构解析

Analysis of Microbial Community Structure in Food Waste Composting with Plug Flow Reactor(PFR)

传统餐厨垃圾好氧堆肥周期长,系统难以稳定连续运行,其中反应器构型和微生物在其处理过程中起到关键作用,但是目前对实际运行条件下的反应器内微生物群落结构的研究较少。通过分析实际运行项目中微生物的多样性与群落结构,为进一步优化餐厨垃圾处理工艺,促进PFR反应器系统的稳定和高效运行,挖掘特定功能微生物,提高资源利用效率提供科学依据。该研究采集德清县11个项目的出料样品,采用Illumina Miseq高通量测序技术,研究其菌群组成、丰度、优势菌群及其相关性。结果表明:1)11个项目的微生物群落组成相似,其中厚壁菌门(Firmicutes)和变形菌门(Proteobacteria)是相对丰度最高的2个菌门,优势菌属为微小杆菌(Exiguobacterium)乳酸杆菌(Lactobacillus),柠檬酸杆菌(Citrobacter),不动杆菌属(Acinetobacter)和假单胞菌(Pseudomonas);2)底物越丰富,进料量越小,越有利于出料的品质;3)出料感官品质高,微生物多样性也较高;4)在OTU水平上,葡萄球菌属与芽孢杆菌属、根瘤菌属均呈负相关,葡萄球菌的迅速增殖抑制了对发酵有益的芽孢杆菌属和根瘤菌属的生长,因此导致样品04-DS的发酵失败;5)餐厨垃圾处理过程中的部分菌属可能具有资源-环境双重属性,例如在出料中相对丰度较高的Pseudomonas,既是常见的致病菌,也具有生产聚羟基脂肪酸酯的功能。该研究明确了新型PFR餐厨垃圾高温强化好氧堆肥处理的微生物群落结构和多样性,并提出了优化处理工艺、强化资源利用效率的建议。

The aerobic composting cycle of traditional food waste is considered as long,and the system is difficult to run steadily and continuously.The reactor configuration and microorganisms play a key role in the treatment of the reactor,however,there are few studies on the microbial community structure in the reactor under actual operating conditions.In this paper,the discharged effluent samples from 11 projects in Deqing County were collected,and Illumina Miseq high-throughput sequencing technology was used to study the flora composition,abundance,dominant flora and their correlations.The result showed:1)the compositions of microbial community from the 11 projects were similar,among which Firmicutes and Proteobacteria were the two with the highest relative abundance,the dominant genus were Exiguobacterium spp.,Lactobacillus spp.,Citrobacter spp.,Acinetobacter spp.,and Pseudomonas spp.;2)the more abundant the substrate,the smaller the feeding quantity,the better the discharge quality;3)the higher the sensory quality of discharge,the higher the microbial diversity;4)at the OTU level(Operational Taxonomic Unit),there were negative correlation among Staphylococcus,Bacillus,and Rhizobium,the rapid proliferation of Staphylococcus inhibited the growth of Bacillus and Rhizobium that were the beneficial microbes to fermentation,as a consequence,the fermentation of sample 04-DS failed;5)some bacteria in the treatment process of food waste showed the dual property of resource and environment,for example,Pseudomonas spp.with relatively high abundance in the discharge,was not only a common pathogen,but also had the function of producing polyhydroxyalkanoates.This study cleared the microbial community structure and diversity in high temperature enhanced aerobic composting of the new type PFR,and put forward suggestions to optimize the treatment process and enhance the resource utilization efficiency.