Quorum quenching, biological characteristics, and microbial community dynamics as key factors for combating fouling of membrane bioreactors

AbstractMembrane fouling is a major challenge in membrane bioreactors (MBRs) for wastewater treatment. This study investigates the effects of disturbance and solid retention time (SRT) on quorum-quenching (QQ) MBRs relative to antifouling efficacy and microbial community change. The fouling rate increases with the applied disturbance at a short SRT, counteracting the antifouling effect of QQ; however, it decreases with QQ at a long SRT. The microbial community appears to be responsible for such MBR behaviors. Several bacterial species belonging to the biofilm-forming group are dominant after disturbance, resulting in substantive membrane fouling. However, the balance between the bacterial species plays a key role in MBR fouling propensity when stabilized. Koflera flava becomes dominant with QQ, leading to reduced membrane fouling. QQ makes the MBR microbial community more diverse, while lowering its richness. QQ with long SRT would be a favorable operational strategy for effective MBR fouling control.

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Temporal Microbial Community Dynamics within a Unique Acid Saline Lake

10.1101/2020.12.17.423355 ◽

2020 ◽

Author(s):

Noor-ul-Huda Ghori ◽

Michael. J. Wise ◽

Andrew. S. Whiteley

Keyword(s):

Microbial Community ◽

Community Dynamics ◽

Bacterial Species ◽

Amplicon Sequencing ◽

Microbial Interactions ◽

Sediment Layer ◽

Microbial Community Dynamics ◽

One Year ◽

Survival Mechanisms ◽

Very High

AbstractLake Magic is one of the acidic hypersaline lakes (ca. 1 km in diameter) present within the Yilgarn Craton in WA. This unique lake exhibits extremely low pH (<1.6) coupled to very high salinity (32% TDS) with the highest concentration of aluminium (1774 mg/L) and silica (510 mg/L) in the world. Previous studies on Lake Magic diversity has revealed that the lake hosts acidophilic, acidotolerant, halophilic and halotolerant bacterial species. These studies provide indicators of the population residing within the lake. However, they do not emphasize the survival mechanisms adopted by the resident microorganisms and how the diversity of microbial populations residing within the lake changes during the dynamic stages of flooding, evapo-concentration and desiccation. We have studied the bacterial and fungal diversity in Lake Magic via amplicon sequencing and functional analysis through different stages of the lake in a span of one year, in the salt and sediment layer. Our results highlight that the diversity in Lake Magic is strongly driven by the pH and salt concentrations at different stages of the lake. The microbial community becomes more specialised in specific functions during more extreme stages. This also suggests that microbial interactions are involved in stabilising the ecosystem and is responsible for the resistance and resilience of these communities as the interactions of these microbes create a safe haven for other microbes to survive during more extreme stages.

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Mesophilic anaerobic digestion of thermally hydrolyzed sludge in anaerobic membrane bioreactor: Long-term performance, microbial community dynamics and membrane fouling mitigation

Journal of Membrane Science ◽

10.1016/j.memsci.2020.118264 ◽

2020 ◽

Vol 612 ◽

pp. 118264

Author(s):

Chengxin Niu ◽

Yang Pan ◽

Xueqin Lu ◽

Shasha Wang ◽

Zhongyi Zhang ◽

...

Keyword(s):

Microbial Community ◽

Anaerobic Digestion ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Community Dynamics ◽

Microbial Community Dynamics ◽

Fouling Mitigation ◽

Long Term Performance ◽

Term Performance

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Microbial community dynamics in replicate membrane bioreactors – Natural reproducible fluctuations

Water Research ◽

10.1016/j.watres.2008.11.021 ◽

2009 ◽

Vol 43 (3) ◽

pp. 842-852 ◽

Cited By ~ 50

Author(s):

Michael W. Falk ◽

Kyung-Guen Song ◽

Michael G. Matiasek ◽

Stefan Wuertz

Keyword(s):

Microbial Community ◽

Community Dynamics ◽

Membrane Bioreactors ◽

Microbial Community Dynamics

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Temporal Microbial Community Dynamics Within a Unique Acid Saline Lake

Frontiers in Microbiology ◽

10.3389/fmicb.2021.649594 ◽

2021 ◽

Vol 12 ◽

Author(s):

Noor-Ul-Huda Ghori ◽

Michael J. Wise ◽

Andrew S. Whiteley

Keyword(s):

Microbial Community ◽

Environmental Conditions ◽

Fungal Diversity ◽

Community Dynamics ◽

Bacterial Species ◽

Amplicon Sequencing ◽

Fungal Species ◽

Hypersaline Lake ◽

Microbial Community Dynamics ◽

Abundance And Diversity

Lake Magic is an extremely acidic, hypersaline lake found in Western Australia, with the highest concentrations of aluminum and silica in the world. Previous studies of Lake Magic diversity have revealed that the lake hosts acid- and halotolerant bacterial and fungal species. However, they have not canvassed microbial population dynamics across flooding, evapo-concentration and desiccation stages. In this study, we used amplicon sequencing and potential function prediction on sediment and salt mat samples. We observed that the bacterial and fungal diversity in Lake Magic is strongly driven by carbon, temperature, pH and salt concentrations at the different stages of the lake. We also saw that the fungal diversity decreased as the environmental conditions became more extreme. However, prokaryotic diversity was very dynamic and bacteria dominated archaeal species, both in abundance and diversity, perhaps because bacteria better tolerate the extreme variation in conditions. Bacterial species diversity was the highest during early flooding stage and decreased during more stressful conditions. We observed an increase in acid tolerant and halotolerant species in the sediment, involved in functions such as sulfur and iron metabolism, i.e., species involved in buffering the external environment. Thus, due to activity within the microbial community, the environmental conditions in the sediment do not change to the same degree as conditions in the salt mat, resulting in the sediment becoming a safe haven for microbes, which are able to thrive during the extreme conditions of the evapo-concentration and desiccation stages.

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