摘要
为探究厨余垃圾高固厌氧消化系统的起泡特征胞外聚合物(EPS)及其微生物学机制,本研究在半连续式厌氧消化反应器中通过负荷扰动诱导起泡现象,系统考察了起泡进程中反应器各类参数及微生物群落结构的动态响应.结果表明:泡沫高度与溶解性EPS中的疏水性蛋白质,总EPS中的疏水性腐殖质及疏水性蛋白质均呈显著正相关,这三类物质为潜在的起泡特征EPS.微生物分析发现,Fastidiosipila,Rikenellaceae_RC9_gut_group,W5053和W5属的丰度与泡沫高度及特征EPS浓度显著正相关(P≤0.05),指示它们是导致系统起泡的关键微生物.理化与生化参数的多元统计分析结果指示:随着负荷持续提升,累积的VFA刺激了Fastidiosipila,Rikenellaceae_RC9_gut_group,W5053和W5的增殖,随后它们大量合成特征EPS以应对环境胁迫;过量分泌的特征EPS定向排列于气泡表面,增强了液膜机械强度,减缓了气泡破裂.不同于其它特征微生物主要在液相中发挥作用,W5还可随气泡迁移至泡沫层,通过分泌疏水性腐殖质进一步促进泡沫稳定.本研究为厨余垃圾消泡策略的制定提供了理论基础.
To identify the key extracellular polymeric substance(EPS)fractions and elucidate the microbial mechanisms driving foaming in high solid anaerobic digestion(HSAD)of food waste,organic loading rate(OLR)perturbations were introduced in a semi-continuous anaerobic digestion(AD)reactor to induce the foaming phenomenon.The responses of physicochemical parameters and microbial community structure were systematically investigated.The results indicated that foaming height was positively correlated with hydrophobic proteins in soluble EPS,as well as with hydrophobic humic substances(HU)and hydrophobic proteins(PN)in total EPS.This suggests that these three EPS fractions are potential key contributors associated with foaming.Microbial analyses revealed a significant positive correlation between the abundance of Fastidiosipila,Rikenellaceae_RC9_gut_group,W5053,and W5 genera with foaming height and the concentrations of key EPS fractions(P≤0.05),indicating their role as key microorganisms contributing to AD foaming.Additionally,multivariate statistical analyses of physicochemical and microbial parameters indicated that,the continuous increase in OLR stimulated the accumulation of volatile fatty acids(VFA),which in turn promoted the proliferation of Fastidiosipila,Rikenellaceae_RC9_gut_group,W5053,and W5.These microorganisms subsequently synthesized substantial amounts of key EPS fractions in response to environmental stress.The over-secreted EPS were oriented and arranged on the surface of bubbles,enhancing the mechanical strength of the liquid membrane and slowing down bubble rupture.Unlike other key microorganisms that primarily act in the liquid phase,W5 also migrated with the bubbles to the foam layer,further promoting foam stabilization by secreting hydrophobic HU.This study provides a theoretical basis for developing defoaming strategies for AD systems treating food waste.
作者
管润
李蕾
叶文杰
刘俊豪
韩林沛
彭绪亚
GUAN Run;LI Lei;YE Wen-jie;LIU Jun-hao;HAN Lin-pei;PENG Xu-ya(Key Laboratory of Three Gorges Reservoir Region’s Eco-Environment,Ministry of Education,Chongqing University,Chongqing 400045,China)
出处
《中国环境科学》
北大核心
2025年第10期5607-5618,共12页
China Environmental Science
基金
国家自然科学基金资助项目(52170124)
新重庆青年创新人才项目(CSTB2024NSCQ-QCXMX0088)。
关键词
厨余垃圾
厌氧消化
泡沫
胞外聚合物
微生物群落
food waste
anaerobic digestion
foam
extracellular polymers
microbial community
