复合菌剂启动餐厨垃圾推流工艺(PFR)堆肥化过程中的微生物群落动态解析

Dynamic Analysis of Microbial Community in PFR Composting Process of Food Waste Starting Up with Microbial Inoculum

好氧堆肥是我国餐厨垃圾资源化的主要方法,微生物在其处理过程中起到关键作用,但是目前对其启动微生物及不同工艺单元微生物群落结构的研究较少。通过对比有无菌种启动发酵体系,并分析各工艺单元的微生物多样性与群落结构,为改进餐厨垃圾资源化处理技术、提高资源利用效率提供科学依据。该研究采集中源创能餐厨垃圾处理厂的各个工艺单元及出料样品,以无菌系发酵为对照,采用Miseq高通量测序技术,研究启动菌剂对各工艺单元菌群组成、丰度、优势菌群的影响。结果表明:1、餐厨底物经复合菌种发酵后微生物多样性在不断增加(香农指数各个单元的变化规律为2.69—2.81—3.39),而无菌系启动的发酵体系微生物多样性并无显著增加,且杂乱无规律。2、主成分分析表明复合菌系启动下,前两个仓的样品聚类到了一起,说明发酵体系需要一个短暂的适应期。3、在门水平上,复合菌种发酵体系中Firmicutes(厚壁菌门)始终占优势地位,其次是变形菌门,而无菌种发酵体系中Proteobacteria(变形菌门)为优势菌门,Firmicutes(厚壁菌门)次之,在属水平上,复合菌种发酵体系的优势菌属为Lactobacillus(乳杆菌)和Exiguobacterium(微小杆菌),而无菌种发酵体系的优势菌属为Ignatzschineria(依格纳季氏菌属)和Lactobacillus(乳杆菌)。4、经过KEGG功能注释后发现两体系均由碳水化合物运输代谢和氨基酸转运代谢占主导,系相同的餐厨底物所致。该研究明确了典型复合菌剂启动下的餐厨垃圾好氧堆肥处理工艺单元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。

Aerobic composting can be considered as one of the main methods of kitchen waste recycling in our country,microbial community play a significant role in its processing.However,there are few researches focusing on the starting microbes and microbial community structure in different technological units of a project.The microbial diversity and community structure of each technological unit were analyzed by comparing the start-up fermentation system with or without microbial inoculum,so as to provide scientific basis for improving the recycling technology of kitchen waste.Samples in this study were collected from each technical unit in Zhongyuan Chuangneng Kitchen Waste Treatment Plant.Adopting Miseq high-throughput sequencing technology,the effects of starting microbial agent on the composition,abundance and dominant flora of each technical unit were studied with fermentation system without inoculum as the control.The result showed that:1、The microbial diversity of kitchen substrates increased continuously after starting up of fermentation with starting microbes(the variation rule of Shannon index in each technique unit was 2.69—2.81—3.39);however,the microbial diversity of the fermentation system without inoculum did not increase significantly,moreover,it was even disordered.2、the analysis of main ingredient showed that,with the starting microbial agent,samples in the first two positions have clustered together,indicating that fermentation system required a short adaptation period.3、at the phylum level,with starting microbial agent,Firmicutes was always stayed the dominant position in the fermentation system,followed by Proteobacteria;nevertheless,Proteobacteria played a significant role in the system without inoculum,then Firmicutes.At the level of genus,the dominant genus in system with starting microbial agent were Lactobacillus and Exiguobacterium;and Ignatzschineria and Lactobacillus were the dominant genus in the system without inoculum.4、with the starting microbial agent,streptococci was reduced with the development of fermentation process;however,Lactobacillus,which was beneficial to fermentation,increased continuously.As a consequence,kitchen waste was harmlessly treated,the discharge met the requirements of NY525-2012.5 of the Ministry of Agriculture)After KEGG functional annotation,it was found that both systems were dominated by carbohydrate transport metabolism and amino acid tranfer metabolism,which were caused by the same kitchen substrate.This study identified the microbial community structure and diversity of the aerobic composting unit of food and kitchen waste under the initiation of typical starting bacteria,and some suggestions on optimizing the processing and strengthening the resource utilization efficiency were put forward.