Mixotrophic anammox bacteria outcompete dissimilatory nitrate reduction and denitrifying bacteria in propionate-containing wastewater.

Organic carbon can influence nitrogen removal during the anaerobic ammonia oxidation (anammox) process. Propionate, a common organic compound in pretreated wastewater, its impacts on mixotrophic anammox bacteria and the underlying mechanisms have not been fully elucidated. This study investigated the core metabolism and shift in behavior patterns of mixotrophic Candidatus Brocadia sapporoensis (AMXB) under long-term propionate exposure.

Non-electroactive bacteria behave variously in AnMBR biofilm control using electric field.

Electroactive bacteria are often regarded as key players responding to electric fields that are used to control biofilm development during AnMBR (anaerobic membrane bioreactor) operation. Consequently, little attention has been given to non-electroactive bacteria in the same systems because of their incapability to acquire and transfer electrons directly. However, in this study, we identified some functionally important non-electroactive bacteria from biofilm established under low-voltage (0, 0.

Unravelling biosynthesis and biodegradation potentials of microbial dark matters in hypersaline lakes.

Biosynthesis and biodegradation of microorganisms critically underpin the development of biotechnology, new drugs and therapies, and environmental remediation. However, most uncultured microbial species along with their metabolic capacities in extreme environments, remain obscured. Here we unravel the metabolic potential of microbial dark matters (MDMs) in four deep-inland hypersaline lakes in Xinjiang, China.

BASALT refines binning from metagenomic data and increases resolution of genome-resolved metagenomic analysis.

Metagenomic binning is an essential technique for genome-resolved characterization of uncultured microorganisms in various ecosystems but hampered by the low efficiency of binning tools in adequately recovering metagenome-assembled genomes (MAGs). Here, we introduce BASALT (Binning Across a Series of Assemblies Toolkit) for binning and refinement of short- and long-read sequencing data. BASALT employs multiple binners with multiple thresholds to produce initial bins, then utilizes neural networks to identify core sequences to remove redundant bins and refine non-redundant bins.

Effect of hydraulic regime on sulfur-packed bed performance: Denitrification and disproportionation.

Sulfur-packed beds (SPBs) have been increasingly incorporated into constructed wetland systems to overcome limitations in achieving satisfactory nitrate removal efficiency. However, the underlying impact of hydraulic regimes on SPB performance remains understudied. This study investigated the performance of a pilot-scale SPB, encompassing sulfur autotrophic denitrification (SAD) and sulfur disproportionation (SDP) processes, under various horizontal flow (HF) and vertical flow (VF) regimes.

Managing microbial sulfur disproportionation for optimal sulfur autotrophic denitrification in a pilot-scale elemental sulfur packed-bed bioreactor.

Elemental sulfur packed-bed (SPB) bioreactors for autotrophic denitrification have gained more attention in wastewater treatment due to their organic carbon-free operation, low operating cost, and minimal carbon emissions. However, the rapid development of microbial S-disproportionation (MSD) in SPB reactor during deep denitrification poses a significant drawback to this new technology. MSD, the process in which sulfur is used as both an electron donor and acceptor by bacteria, plays a crucial role in the microbial-driven sulfur cycle but remains poorly understood in wastewater treatment setups.

The impact of perfluorooctanoic acid shock on hydrogen-driven nitrate and arsenate removal.

Perfluorooctanoic acid (PFOA) is a type of toxic per- and poly-fluoroalkyl substance (PFAS) commonly found in groundwater due to its use in firefighting and industrial applications. The main purpose of this study was to investigate the influence of PFOA shock on the biological performance of a hydrogen-driven bioreactor for nitrate and arsenate removal. Four hydrogen-driven removal reactors (HdBRs) used for the simultaneous removal of nitrate and arsenal were operated with concentrations of either 0, 1, 5, and 10 mg/L of PFOA to induce shock on the systems and examine the corresponding bacterial response.

Dissimilatory sulfate reduction in an anaerobic biofilm reactor for tofu processing wastewater treatment: Bacterial community and their functional genes.

Dissimilatory sulfate reduction (DSR) is the key sulfur cycle that transforms sulfate to sulfide. This process leads to odour issues in wastewater treatment. However, few studies have focused on DSR during treating food processing wastewater with high sulfate.

Double-edged sword effects of dissimilatory nitrate reduction to ammonium (DNRA) bacteria on anammox bacteria performance in an MBR reactor.

Dissimilatory nitrate reduction to ammonium (DNRA) bacteria imposing double-edged sword effects on anammox bacteria were investigated in an anammox-membrane bioreactor (MBR) experiencing an induced crash-recovery event. During the experiment, the anammox-MBR was loaded with NH-N:NO-N ratios (RatioNH-N: NO-N) of 1.20-1.

Identification of dissimilatory nitrate reduction to ammonium (DNRA) and denitrification in the dynamic cake layer of a full-scale anoixc dynamic membrane bioreactor for treating hotel laundry wastewater.

Identification of dissimilatory nitrate reduction to ammonium (DNRA) and denitrification in the dynamic cake layer of a full-scale anoixc dynamic membrane bioreactor (AnDMBR) for treating hotel laundry wastewater was studied. A series of experiments were conducted to understand the contributions of DNRA and canonical denitrification activities in the dynamic cake layer of the AnDMBR. The dynamic cake layer developed included two phases - a steady transmembrane pressure (TMP) increase at 0.

Biotransformation of 6:2 Fluorotelomer Thioether Amido Sulfonate in Aqueous Film-Forming Foams under Nitrate-Reducing Conditions.

Despite the prevalence of nitrate reduction in groundwater, the biotransformation of per- and polyfluoroalkyl substances (PFAS) under nitrate-reducing conditions remains mostly unknown compared with aerobic or strong reducing conditions. We constructed microcosms under nitrate-reducing conditions to simulate the biotransformation occurring at groundwater sites impacted by aqueous film-forming foams (AFFFs). We investigated the biotransformation of 6:2 fluorotelomer thioether amido sulfonate (6:2 FtTAoS), a principal PFAS constituent of several AFFF formulations using both quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) and qualitative high-resolution mass spectrometry analyses.

Core carbon fixation pathways associated with cake layer development in an anoxic-oxic biofilm-membrane bioreactor treating textile wastewater.

Microbial carbon fixation pathways have not yet been adequately understood for their role in membrane case layer formation processes. Carbon fixation bacteria can play critical roles in either causing or enhancing cake layer formation in some autotrophic-prone anoxic conditions, such as sulfur-cycling conditions. Understanding the microbes capable of carbon fixation can potentially guide the design of membrane biofouling mitigation strategies in scientific ways.

Dissimilatory sulfate reduction in the cake layer of a full-scale anaerobic dynamic membrane bioreactor for hotel laundry wastewater treatment: Bacterial community and functional genes.

Dissimilatory sulfate reduction (DSR) in cake layer of full-scale anaerobic dynamic membrane bioreactor for treating hotel laundry wastewater was studied. Change (Δ) of sulfate concentration (ΔSO) was positively correlated to dynamic cake layer (DCL) development, while ΔS was negatively correlated. ΔSO and ΔS remained around 1.

Specific Denitrifying and Dissimilatory Nitrate Reduction to Ammonium Bacteria Assisted the Recovery of Anammox Community From Nitrite Inhibition.

The anaerobic ammonium oxidation (anammox) by autotrophic anaerobic ammonia-oxidizing bacteria (AnAOB) is a biological process used to remove reactive nitrogen from wastewater. It has been repeatedly reported that elevated nitrite concentrations can severely inhibit the growth of AnAOB, which renders the anammox process challenging for industrial-scale applications. Both denitrifying (DN) and dissimilatory nitrate reduction to ammonium (DNRA) bacteria can potentially consume excess nitrite in an anammox system to prevent its inhibitory effect on AnAOB.

Assessing effects of Ca addition on membrane bioreactor performance and macro-floc sludge characteristics.

Calcium ions (Ca) can trigger coagulation-flocculation process to form macro-flocculated sludge (MFS). Thus, dosing Ca-containing reagents into membrane bioreactors (MBRs) is considered as a promising approach to mitigate membrane biofouling. However, a mechanistic understanding of Ca addition to MBR performance remains elucidated, such as physicochemical characteristics of MFS and their functionality variations.

Development of radio-frequency identification (RFID) sensors suitable for smart-monitoring applications in sewer systems.

Sanitary and stormwater sewers are buried assets that play important roles in the prevention of diseases and the reduction of health risks for our societies. Due to their hidden nature, these assets are not frequently assessed and maintained to optimal conditions. The lack of maintenance can cause sewer blockages and overflows that result in the release of pathogens into the environment.

Challenges in biodegradation of non-degradable thermoplastic waste: From environmental impact to operational readiness.

Non-degradable plastics such as polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) are among the most generated plastic wastes in municipal and industrial waste streams. The mismanagement of abandoned plastics and toxic plastic additives have threatened marine and land fauna as well as human beings for several decades. The available thermal processes can degrade plastic at pilot- and commercial-scale.

Assimilatory and dissimilatory sulfate reduction in the bacterial diversity of biofoulant from a full-scale biofilm-membrane bioreactor for textile wastewater treatment.

Assimilatory and dissimilatory sulfate reduction (ASR and DSR) are the core bacterial sulfate-reducing pathways involved in wastewater treatment. It has been reported that sulfate-reducing activities could happen within biofoulants of membrane bioreactors during wastewater treatment. Biofoulants are mainly microbial products contributing membrane fouling and subsequent rising energy consumption in driving membrane filtration.

Core nitrogen cycle of biofoulant in full-scale anoxic & oxic biofilm-membrane bioreactors treating textile wastewater.

Core nitrogen cycle within biofoulant in full-scale anoxic & oxic biofilm-membrane bioreactor (bMBR) treating textile wastewater was investigated. Wastewater filtered through membrane with biofoulant had elevated NH-N and NO-N concentrations corresponding to decreased NO-N concentrations. Nevertheless, total nitrogen concentrations did not change significantly, indicating negligible nitrogen removal activities within biofoulant.

Degradation of plastic waste using stimulated and naturally occurring microbial strains.

The capability of different strains derived from soil, activated sludge, farm sludge, and worms' excreta were investigated for biodegradation of high-density polyethylene, polystyrene foam, polypropylene and polyethylene terephthalate in unstimulated and stimulated conditions. Biodegradation using naturally occurring microbial strains examined in mixed (270 days) and individual (100 days) systems, while HO stimulated strains were tested only in the mixed system (30 days). Penicillium raperi, Aspergillus flavus, Penicillium glaucoroseum and Pseudomonas sp.

Assessing inorganic components of cake layer in A/O membrane bioreactor for physical-chemical treated tannery effluent.

In this study, an anoxic-oxic membrane bioreactor (A/O-MBR), was used to treat effluent tannery wastewater pretreated by physicochemical processes. The A/O-MBR performed well during the experimental period and was able to produce a high-quality effluent containing 90 ± 10 mg-COD/L and 0.5 ± 0.

Metabolomic Analysis Reveals Contributions of Citric and Citramalic Acids to Rare Earth Bioleaching by a Fungus.

Conventional methods for extracting rare earth elements from monazite ore require high energy inputs and produce environmentally damaging waste streams. Bioleaching offers a potentially more environmentally friendly alternative extraction process. In order to better understand bioleaching mechanisms, we conducted an exo-metabolomic analysis of a previously isolated rare earth bioleaching fungus from the genus (GenBank accession numbers KM874779 and KM 874781) to identify contributions of compounds exuded by this fungus to bioleaching activity.

Microbial community in in-situ waste sludge anaerobic digestion with alkalization for enhancement of nutrient recovery and energy generation.

Microbial community in in-situ waste sludge anaerobic digestion with alkalization for enhancement of nutrient recovery and energy generation was studied. Firmicutes, Proteobacteria and Bacteroidetes phylum became the majority in the microbial community, especially Firmicutes showed the predominate role in the community due to its thick cell wall structure, potential ability hydrolysis and hydrogenogenic acidogenesis. Anaerobic digestion with alkalization caused the obvious microbial diversity decrease, and over 50% of minority bacteria grew up in quantity from original sludge.

Potential effects of suspended TiO nanoparticles on activated sludge floc properties in membrane bioreactors.

With the rapid development and application of consumer products containing nanoparticles (NPs), especially titanium dioxide (TiO) NPs, the potential effects of suspended NPs on wastewater treatment has been a concern over the recent years. This study investigated the potential effects of suspended TiO NPs on activated sludge flocculation properties in a membrane bioreactor (MBR). Results showed that suspended TiO NPs inhibited the viability of activated sludge flocs, and led to bacterial protein secretion for bacterial protection, causing an overall protein increase of soluble microbial products.