Related Experiment Video
Updated: Jun 3, 2026
08:28
Creating Rapid Oxygen Oscillations in Microbial Single-cell Growth Analysis using a Microfluidic Double-layer Device
Published on: July 18, 2025
Linking microbial community structure to membrane biofouling associated with varying dissolved oxygen concentrations
1State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. dawengao@gmail.com
Bioresource Technology
|March 18, 2011
Summary
Low dissolved oxygen (DO) in aerobic membrane bioreactors (MBR) increases extracellular polymeric substance (EPS) in biocake, leading to severe membrane biofouling. Microbial community shifts are key drivers of this process.
Area of Science:
- Environmental Microbiology
- Biotechnology
- Water Treatment
Background:
- Aerobic membrane bioreactors (MBRs) are crucial for wastewater treatment.
- Biofouling, particularly membrane fouling, is a significant operational challenge in MBRs.
- Extracellular polymeric substances (EPS) and soluble microbial products (SMP) contribute to biofouling.
Purpose of the Study:
- To investigate the influence of dissolved oxygen (DO) concentration on EPS and SMP generation in MBRs.
- To analyze microbial community variations in response to DO levels.
- To determine the relationship between microbial community structure, EPS, and membrane biofouling.
Main Methods:
- Utilized an aerobic membrane bioreactor (MBR) under controlled DO conditions.
- Performed 16S rDNA fingerprinting to analyze microbial community structure.
- Quantified EPS and SMP concentrations in mixed liquor and biocake.
- Correlated membrane fouling rates with EPS content.
Main Results:
- Low DO concentration (0.5 mg L(-1)) led to increased EPS in biocake.
- Observed a microbial community succession from Betaproteobacteria to Deltaproteobacteria in biocake.
- High EPS concentration in biocake under low DO significantly correlated with severe biofouling (R² > 0.99).
- EPS in biocake showed a stronger correlation with fouling than EPS in mixed liquor.
Conclusions:
- DO concentration is a critical factor regulating EPS production and microbial community structure in MBRs.
- Microbial community shifts, particularly in biocake, are directly linked to EPS accumulation and subsequent biofouling.
- Controlling DO levels is essential for mitigating biofouling and optimizing MBR performance.
Related Concept Videos
01:30Marine Microbial Ecology
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
01:22Microenvironments
Microorganisms inhabit highly localized spaces known as microenvironments, which are defined by distinct physical and chemical characteristics. These include oxygen concentration, pH, temperature, light availability, and nutrient levels. The conditions within a microenvironment can differ markedly from those in the surrounding area and significantly influence microbial growth, metabolism, and community structure.Microenvironments often display sharp physicochemical gradients over small spatial...
01:24Freshwater Microbial Ecology
Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...
01:28Introduction to Microbial Ecology
Microbial ecology examines the complex web of interactions and diversity among microorganisms within various ecosystems. This field seeks to understand how microbial populations adapt to and influence their environments and how these interactions shape broader ecological processes. Microbes are integral to ecosystem function, participating in nutrient cycling, energy flow, and the maintenance of environmental homeostasis.An ecosystem represents a dynamic interaction between living organisms...
01:19Methods to Assess Microbial Communities
Microbial communities, comprising bacteria, archaea, and eukaryotic microorganisms, inhabit diverse ecosystems and play crucial roles in environmental and biological processes. Their diversity is defined by three main parameters: species richness (the number of distinct species), species abundance (the relative quantity of each species), and species evenness (how uniformly individual species are distributed in various locations). These factors together shape the structure and ecological balance...