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In this study, a temperature-sensitive fabric with antibacterial properties was prepared by the formation of silver nanoparticles (AgNPs) on nonwoven poly (propylene) (PP) grafted with poly (N-iso-propylacrylamide) (PNIPAAm-PP). First, PNIPAAm was grafted onto corona-treated nonwoven PP. Afterwards, silver nanoparticles were synthesized on the temperature-sensitive hydrogel layer grafted to the surface of nonwoven PP by the reduction of silver ions (Ag+). Fourier transform infra-red spectroscopy confirmed the presence of PNIPAAm on the nonwoven PP. scanning electron microscopy-energy dispersive X-ray spectroscopy was used to investigate surface morphology and the presence of silver particles in the samples. Inductively coupled-plasma atomic emission spectroscopy revealed that the Ag content in Ag-functionalized PNIPAAm-PP was significantly higher than Ag-functionalized corona-treated PP with the same concentration of silver solution. Moreover, the results of the swelling rate experiment confirmed that PNIPAAm-PP maintained temperature-sensitive properties after functionalizing with Ag. The results showed that the formation of AgNPs with enhancement in antibacterial property was possible onto PNIPAAm-PP. [ABSTRACT FROM AUTHOR]

The effect of limiting biofilm volume using carriers with maximum thickness control on the performance and microbial community composition was investigated in anaerobic moving-bed biofilm reactors (AnMBBRs). Three parallel, continuous AnMBBRs (4 L) were operated (288 d, 24/36 °C) to treat the soluble fraction of a wastewater from a food-manufacturing facility. Two different biofilm carriers controlling maximum biofilm thickness at 200 and 1000 µm (AnoxK™Z-200 and Z-1000) were used in the three reactors, targeting the same projected surface area for biofilm growth (410 m2/reactor): R200 (Z-200), R1000 (Z-1000) and RMix (both Z-200 and Z-1000). The composition of the bacterial (16S rRNA V1-V3) and methanogenic (mcr A gene) communities was analysed using amplicon sequencing. Under relatively constant organic loads (3.6–4.2 gSCOD/Ld, 34–39 gSCOD/m2d, hydraulic retention time=7.7–8 h), R200 presented lower soluble chemical oxygen demand (SCOD) removals (51–60%) than the other reactors (R100 = 91–93%, RMix = 86–91%), likely due to a limited amount of active protected biofilm volume. Lower SCOD removals were associated with higher concentrations of volatile fatty acids in the effluent (R200 =400–800 mgCOD/L; R1000 and RMix<200 mgCOD/L) and lower methane production (R200 =0.66; R1000 =0.72; RMix=0.73 gCH 4 -COD/gSCODremoved). The Z-200 carriers contained a different fermentative/acidogenic bacterial community abundant in representatives of the families Christensenellaceae , Anaerovoracaceae and Synergistaceae, and led to less amount of biofilm biomass growth, albeit more active than that of carriers allowing for thicker biofilms (Z-1000). In contrast, methanogenic populations were less sensitive to biofilm thickness restraint by these carriers. This study shows for the first time that limiting biofilm volume in MBBR carriers can impact the performance and bacterial community in AnMBBR biofilms. [Display omitted] • Limiting biofilm volume in carriers can impact the performance of anaerobic MBBRs. • Lower C removals and biogas production with biofilms thinner than 200 µm. • Carriers that limit thickness below 200 µm seem to contain more active biomass. • Carriers limiting biofilm volume contain distinct bacterial community in AnMBBR. • Methanogenic community composition less sensitive to biofilm thickness restraint. [ABSTRACT FROM AUTHOR]

Members of the genus Tetrasphaera are considered to be putative polyphosphate accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) from wastewater. Although abundant in Danish full-scale wastewater EBPR plants, how similar their ecophysiology is to 'Candidatus Accumulibacter phosphatis' is unclear, although they may occupy different ecological niches in EBPR communities. The genomes of four Tetrasphaera isolates (T. australiensis, T. japonica, T. elongata and T. jenkinsii) were sequenced and annotated, and the data used to construct metabolic models. These models incorporate central aspects of carbon and phosphorus metabolism critical to understanding their behavior under the alternating anaerobic/aerobic conditions encountered in EBPR systems. Key features of these metabolic pathways were investigated in pure cultures, although poor growth limited their analyses to T. japonica and T. elongata. Based on the models, we propose that under anaerobic conditions the Tetrasphaera-related PAOs take up glucose and ferment this to succinate and other components. They also synthesize glycogen as a storage polymer, using energy generated from the degradation of stored polyphosphate and substrate fermentation. During the aerobic phase, the stored glycogen is catabolized to provide energy for growth and to replenish the intracellular polyphosphate reserves needed for subsequent anaerobic metabolism. They are also able to denitrify. This physiology is markedly different to that displayed by 'Candidatus Accumulibacter phosphatis', and reveals Tetrasphaera populations to be unusual and physiologically versatile PAOs carrying out denitrification, fermentation and polyphosphate accumulation. [ABSTRACT FROM AUTHOR]

The ecophysiology of uncultured Rhodocyclus-related polyphosphate-accumulating organisms (PAO) present in three full-scale enhanced biological phosphorus removal (EBPR) activated sludge plants was studied by using microautoradiography combined with fluorescence in situ hybridization. The investigations showed that these organisms were present in all plants examined and constituted 5 to 10, 10 to 15, and 17 to 22% of the community biomass. The behavior of these bacteria generally was consistent with the biochemical models proposed for PAO, based on studies of lab-scale investigations of enriched and often unknown PAO cultures. Rhodocyclus-related PAO were able to accumulate short-chain substrates, including acetate, propionate, and pyruvate, under anaerobic conditions, but they could not assimilate many other low-molecular-weight compounds, such as ethanol and butyrate. They were able to assimilate two substrates (e.g., acetate and propionate) simultaneously. Leucine and thymidine could not be assimilated as sole substrates and could only be assimilated as cosubstrates with acetate, perhaps serving as N sources. Glucose could not be assimilated by the Rhodocyclus-related PAO, but it was easily fermented in the sludge to products that were subsequently consumed. Glycolysis, and not the tricarboxylic acid cycle, was the source that provided the reducing power needed by the Rhodocyclus-related PAO to form the intracellular polyhydroxyalkanoate storage compounds during anaerobic substrate assimilation. The Rhodocyclus-related PAO were able to take up orthophosphate and accumulate polyphosphate when oxygen, nitrate, or nitrite was present as an electron acceptor. Furthermore, in the presence of acetate growth was sustained by using oxygen, as well as nitrate or nitrite, as an electron acceptor. This strongly indicates that Rhodocyclus-related PAO were able to denitrify and thus played a role in the denitrification occurring in full-scale EBPR plants. [ABSTRACT FROM AUTHOR]

The in situ physiology of the filamentous sulphur bacterium Thiothrix spp. was investigated in an industrial wastewater treatment plant with severe bulking problems as a result of overgrowth of Thiothrix. Identification and enumeration using fluorescence in situ hybridization (FISH) with species-specific 16S and 23S rRNA probes revealed that 5–10% of the bacteria in the activated sludge were Thiothrix spp. By using a combination of FISH and microautoradiography it was possible to study the in situ physiology of probe-defined Thiothrix filaments under different environmental conditions. The Thiothrix filaments were very versatile and showed incorporation of radiolabelled acetate and/or bicarbonate under heterotrophic, mixotrophic and chemolithoautotrophic conditions. The Thiothrix filaments were active under anaerobic conditions (with or without nitrate) in which intracellular sulphur globules were formed from thiosulphate and acetate was taken up. Thiothrix-specific substrate uptake rates and growth rates in activated sludge samples were determined under different conditions. Doubling times of 6–9 h under mixotrophic conditions and 15–30 h under autotrophic conditions were estimated. The key properties that Thiothrix might be employing to outcompete other microorganisms in activated sludge were probably related to the mixotrophic growth potential with strong stimulation of acetate uptake by thiosulphate, as well as stimulation of bicarbonate incorporation by acetate in the presence of thiosulphate. [ABSTRACT FROM AUTHOR]

Antibiotic resistance in fungal isolates is increasing on a global scale. Despite knowledge that pig farmers are occupationally exposed to infectious species of fungi, such as Aspergillus spp., little is known regarding their potential exposure to antifungal-resistant Aspergillus spp. The aim of this study is to obtain knowledge regarding the antifungal resistance profiles of isolates of Aspergillus species taken from different source materials—including airborne dust, surface dust, faeces, and straw—within a pig farm. The EUCAST broth microdilution method was used for testing antifungal resistance from 43 isolates of Aspergillus sampled in 3 periods inside a Danish pig farm. Seven species of Aspergillus were obtained, including A. candidus (n = 5), A. fumigatus (n = 5), A. glaucus (n = 13), A. nidulans (n = 2), A. niger (n = 15), A. terreus (n = 1), and A. versicolor (n = 2). Overall, 27.9% of the Aspergillus isolates displayed resistance against at least one antifungal, and 11.6% of Aspergillus isolates displayed resistance against multiple antifungals. The most abundant group exhibiting antifungal resistance was affiliated with the species A. niger, with isolates exhibiting resistance to itraconazole, voriconazole, and caspofungin. One isolate of A. glaucus and two isolates of A. versicolor were resistant to amphotericin B (MIC ≥ 2 mg/L amphotericin B). Antibiotic-resistant fungi were found on all three sampling days. [ABSTRACT FROM AUTHOR]

Recent studies have indicated that Galleria mellonella larvae ingest polyethylene films and the degradation mechanism could inspire biotechnological exploitation for degrading plastic to eliminate global pollution from plastic waste. In this study, we tested the chemical compositions of masticated and ingested different plastic types by G. mellonella. High throughput sequencing of 16S rRNA gene was used to characterize the alteration of the microbial communities derived from salivary glands, gut contents and whole G. mellonella larvae. Our results indicated that G. mellonella is able to masticate polyethylene (PE), expanded polystyrene (EPS) and polypropylene (PP) and convert it to small particles with very large and chemically modified surfaces. The characteristics of the polymer affect the rate of damage. Formation of functional carbonyl groups on the appearance of oxidized metabolic intermediates of polyolefins in the frass samples observed. We found that the mastication of EPS, PP or PE could significantly alter the microbial composition in the gut content while it did not appear to influence the salivary glands microbial community. Representatives of Desulfovibrio vulgaris and Enterobacter grew with the PE diet while mastication of polystyrene and polypropylene increased the abundance of Enterococcus. The evaluation of bacterial communities in whole larvae confirmed the obtained result and additionally showed that the abundance of Paenibacillus, Corynebacterium and Commamonadaceae increased by Styrofoam (EPS) consumption. [Display omitted] • Chemical modifications of the polyethylene, polystyrene and polypropylene after exposure to G. mellonella. • mastication of EPS, PP or PE could significantly alter the microbial composition in gut content. • Polyolefin mastication did not influence the salivary glands microbial community. • Representatives of Desulfovibrio vulgaris and Enterobacter were significantly enriched with the PE diets. • mastication of polystyrene and polypropylene increased the abundance of Enterococcus in the gut content. [ABSTRACT FROM AUTHOR]

Simple Summary: Injured European hedgehogs are frequently admitted to hedgehog rehabilitation centres with different types of cuts and injuries. Although not rigorously quantified, a growing concern is that an increasing number of cases may have been caused by robotic lawn mowers. Research indicates that European hedgehogs are in decline. It is therefore important to identify and investigate the factors responsible for this decline to improve the conservation initiatives directed at this species. Because hedgehogs are increasingly associated with human habitation, it seems likely that numerous individuals will encounter several robotic lawn mowers during their lifetimes. Consequently, this study aimed to describe and quantify the effects of robotic lawn mowers on hedgehogs, and we tested 18 robotic lawn mowers in collision with dead hedgehogs. Some models caused extensive damage to the dead hedgehogs, but there were noteworthy differences in the degree of harm inflicted, with some consistently causing no damage. None of the robotic lawn mowers tested was able to detect the presence of dead, dependent juvenile hedgehogs, and no models could detect the hedgehog cadavers without physical interaction. We therefore encourage future collaboration with the manufacturers of robotic lawn mowers to improve the safety for hedgehogs and other garden wildlife species. We tested the effects of 18 models of robotic lawn mowers in collision with dead European hedgehogs and quantified the results into six damage categories. All models were tested on four weight classes of hedgehogs, each placed in three different positions. None of the robotic lawn mowers tested was able to detect the presence of dependent juvenile hedgehogs (<200 g) and all models had to touch the hedgehogs to detect them. Some models caused extensive damage to the hedgehog cadavers, but there were noteworthy differences in the degree of harm inflicted, with some consistently causing no damage. Our results showed that the following technical features significantly increased the safety index of the robotic lawn mowers: pivoting blades, skid plates, and front wheel drive. Based on these findings, we encourage future collaboration with the manufacturers of robotic lawn mowers to improve the safety for hedgehogs and other garden wildlife species. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combined D 2 O, FISH and Raman-SIP for microbial metabolism analysis. • Obtained single-cell substrate rates in complex ecosystems. • Unveiled substrate preferences, kinetics in Methanosarcina , Methanothermobacter. This study addresses the challenge of obtaining in situ information on substrate utilization rates for individual microbial species in complex microbial communities such as anaerobic digester sludge. To overcome this hurdle, a novel approach combining doubly-labelled deuterium, fluorescence in situ hybridization (FISH) and Raman microspectroscopy was developed. The method enables quantitative determination of anabolic heavy hydrogen incorporation into FISH-targeted, exemplified by methanogenic cells from the genera Methanosarcina and Methanothermobacter. The deuterium incorporation rates ascertained by Raman red-shifting of C-Hx vibrational region to C-Dx vibrations, quantified through Raman peak area ratios, were compared for different carbon sources. Methanosarcina exhibited highest kinetic rates with acetate and propionate, while Methanothermobacter demonstrated faster incorporation under acetate and methanol supplementation. This groundbreaking study demonstrates the feasibility of obtaining quantitative metabolic rate information at a single-cell level using deuterium, FISH probes, and Raman microspectroscopy. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is an opportunistic pathogen associated with soft-tissue infections commonly encountered in indoor and farm environments as a component of airborne dust, which can potentially deposit in the respiratory tracts of workers and residents. However, knowledge regarding the survival and inflammatory potential of S. aureus in airborne dust has not been described. The objective of this study was to obtain knowledge on whether the presence of dust during aerosolisation affects the culturability (ability to grow on agar plates), their biofilm forming capacity, viability (using a viability qPCR), and inflammatory potential (using a human granulocyte based assay), and whether time from aerosolisation to subsequent analyses (the resting time) affects these. Aerosols containing S. aureus (DSM6148) in the presence of sterilised airborne dust from a pig farm were found to have higher culturability, viability, inflammatory potential, and ability to form biofilm compared with S. aureus aerosols generated without airborne dust. When aerosols of S. aureus were generated without dust, they showed a reduction in the culturability, as well as the biofilm forming capacity and an extended resting time was associated with a reduction in culturability, and biofilm forming capacity. In contrast, no differences in the viability were observed in samples with different resting times. The lack of a significant effect of different resting times on viability, and the significant effect on culturability, suggests that the stresses of aerosolisation may induce a viable, but not culturable (VBNC) state in S. aureus. A synergistic effect was found between S. aureus and dust concerning their ability to induce inflammation. In conclusion presence of airborne dust during aerosolisation of S. aureus affects the culturability, biofilm forming capacity, and inflammatory potential, but not the viability of S. aureus. This is of importance in relation to hygiene as well as how exposure to S. aureus is measured. [ABSTRACT FROM AUTHOR]

Fungal species composition and site of deposition within the airways affects whether diseases develop and where they may arise. The aim of this study is to obtain knowledge regarding the potential deposition of airborne culturable, viable, and non-viable fungi in the airways of pig farm workers, and how this composition changes over multiple sampling days. Airborne fungi were sampled using impactors and subsequently analyzed using amplicon sequencing and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) fingerprinting. The geometric mean aerodynamic diameter (Dg) of airborne particles with culturable airborne fungi were not affected by sampling days and ranged in size between 3.7 and 4.6 µm. Amplicon sequencing of the internal transcribed spacer region of the rRNA gene operon, in combination with DNA interchelating agents, revealed a large presence of non-viable fungi, but several pathogenic and toxic fungal species were detected in the viable portion. The diversity was found to be significantly associated with the sampling day but did not change significantly over multiple sampling rounds during the same day. The non-viable fraction contained genera typically associated with the pig gastrointestinal tract, such as Kazachstania and Vishniacozyma. In conclusion, the Dg of culturable fungi was between 3.7 and 4.6 µm, and the Dg of the viable and total fungi was 1.5 and 2.1 µm, respectively. The species composition changed over the multiple sampling days. [ABSTRACT FROM AUTHOR]

Polyethylene pollutions are considered inert in nature and adversely affect the entire ecosystem. Larvae of greater wax moth (Galleria mellonella) have the ability to masticate and potentially biodegrade polyethylene films at elevated rates. The wax moth has been thought to metabolize PE independently of gut flora, however the role of the microbiome is poorly understood and degradation by the wax moth might be involved. To determine whether the salivary glands of the wax moth were potentially involved in the PE degradation, it was investigated how surface changes of polyethylene were affected by mastication and consumption. Formation of pitting and degradation intermediates including carbonyl groups, indicated that salivary glands could assist in polyethylene degradation. We investigated the biochemical effect of exposure by PE on the composition of the salivary gland proteome. The expression of salivary proteins was found to be affected by PE exposure. The proteins that were significantly affected by the exposure to PE revealed that the wax moth are undergoing general changes in energy levels, also enzymatic pathways associated to fatty acid beta oxidation during consumption to PE were induced. Unlabelled Image • Chemical modifications of the polyethylene after exposure to G. mellonella • Enhanced expression of protein associated with fatty acid beta oxidation pathway in G. mellonella salivary glands • Reduced expression of Juvenile Hormone Esterase in G. mellonella salivary glands after exposure to polyethylene • Secretory pathways in G. mellonella salivary glands were induced during polyethylene degradation. [ABSTRACT FROM AUTHOR]

Simple Summary: The European hedgehog (Erinaceus europaeus) is a popular visitor in gardens and recreational areas all over Europe, but hedgehog populations are declining. Research exploring the causes of the decline, including exposure to potentially harmful pollutants and metals, may provide relevant information to improve conservation initiatives to protect this species in the wild. Hedgehogs are ground-dwelling mammals, feeding on a range of different food items such as insects, slugs, snails, and earthworms but also eggs, live vertebrates, and carrion, and therefore come into close contact with pollutants present in their habitats and in their prey. This review investigated published research on the occurrence of metals and pollutants in hedgehogs and found that a vast range of different pesticides; rodenticides; persistent organic pollutants (POPs), including organochlorine compounds and brominated flame retardants (BFRs); as well as toxic heavy metals could be detected in samples from hedgehogs representing different European countries. Due to their ecology, combined with the opportunity to apply non-invasive sampling techniques through the collection of spines as sampling material, we suggest that the European hedgehog is a relevant bioindicator species for monitoring the exposure of omnivorous terrestrial wildlife to potential toxicants in urban and rural environments. Monitoring data from several European countries indicate that European hedgehog (Erinaceus europaeus) populations are declining, and research exploring the causes of the decline, including exposure to potentially harmful xenobiotics and metals, may inform conservation initiatives to protect this species in the wild. Hedgehogs are ground-dwelling mammals, feeding on a range of insects, slugs, snails, and earthworms, as well as eggs, live vertebrates, and carrion, including carcasses of apex predator species representing higher levels of the food chain. Consequently, hedgehogs come into close contact with contaminants present in their habitats and prey. This review investigated the studies available on the subject of the occurrence of metals and organic xenobiotics in hedgehogs. This study found that a vast range of different pesticides; persistent organic pollutants (POPs), including organochlorine compounds and brominated flame retardants (BFRs); as well as toxic heavy metals could be detected. Some compounds occurred in lethal concentrations, and some were associated with a potential adverse effect on hedgehog health and survival. Due to their ecology, combined with the opportunity to apply non-invasive sampling techniques using spines as sampling material, we suggest that the European hedgehog is a relevant bioindicator species for monitoring the exposure of terrestrial wildlife to potential toxicants in urban and rural environments. [ABSTRACT FROM AUTHOR]

The biogas produced through anaerobic digestion (AD) of renewable feedstocks is one of the promising alternatives to replace fossil-derived energy. Even though lignocellulosic biomass is the most abundant biomass on earth, only a small fraction is being used towards resources recovery, leaving a great potential unexploited. In this study, the combination of state-of-art genomic techniques and engineered systems were used to further advance the knowledge on biogas production from lignocellulosic-rich residues and the microbiome involved in the anaerobic digestion hereof. A long-term adapted anaerobic microbiome capable of degrading wheat straw as the sole substrate was investigated using protein stable isotope probing (protein-SIP). The results indicated that a diverse microbial community, primarily composed of Firmicutes and Methanogens, played crucial roles in cellulose degradation and methane production. Notably, Defluviitoga tunisiensis, Syntrophothermus lipocalidus, and Pelobacter carbinolicus were identified as direct metabolizers of cellulose, while Dehalobacterium assimilated labelled carbon through cross-feeding. This study provides direct evidence of primary cellulose degraders and sheds light on their genomic composition. By harnessing the potential of lignocellulosic biomass and understanding the microbial communities involved, we can promote sustainable biogas production, contributing to energy security and environmental preservation. [ABSTRACT FROM AUTHOR]

The recent development of techniques to sequence ancient DNA has provided valuable insights into the civilisations that came before us. However, the full potential of these methods has yet to be realised. We extracted ancient DNA from a recently exposed fracture surface of a clay brick deriving from the palace of king Ashurnasirpal II (883–859 BCE) in Nimrud, Iraq. We detected 34 unique taxonomic groups of plants. With this research we have made the pioneering discovery that ancient DNA, effectively protected from contamination inside a mass of clay, can successfully be extracted from a 2900-year-old clay brick. We encourage future research into this subject, as the scientific prospects for this approach are substantial, potentially leading to a deeper understanding of ancient and lost civilisations. [ABSTRACT FROM AUTHOR]

An abstract of the article "Advances in Microscopy: Microautoradiography of Single Cells," by Jeppe Lund Nielsen and Per Halkjær Nielsen is presented.

Soil-dwelling invertebrates, found worldwide, are essential for decomposition of plant litter and other soil processes, requiring adaptations to changes in the climate. The microbiota associated with these animals profoundly impacts their health and fitness. While seasonal changes have been shown to shape vertebrate microbiota, the microbiota of arthropods adapted to winter remains unknown. In this study, we investigated microbiota of two Collembola species with different overwintering strategies, Tomocerus cf. jilinensis and Tomocerus nigrus , in summer and three different periods in winter (early, mid, and late winter) using 16S rRNA gene amplicon sequencing. The results reveal pronounced alterations in microbial diversity and composition of the Collembola driven by seasonal variations and temperatures. Collembola associated microbiota exhibited higher Shannon diversity during mid and late winter. Furthermore, early, mid, and late winter periods were characterized by an enrichment of representatives from Hungateiclostridiaceae , Pseudomonas , and Pedobacter , respectively. Distinct seasonal patterns in microbiota were observed across different Collembola species. Bacterial community networks in winter Collembola were predominatly marked by positive interactions. Ground temperature exhibited a negative correlation with the Shannon index of Collembola-associated bacteria and the relative abundance of Comamonadaceae , Renibacterium , Mycobacterium , Sphingomonas , and Aeromicrobium. Our study indicates that season alters Collembola associated microbiota and these microbial changes could facilitate Collembola activity in low temperatures. Overall, our study extends our knowledge of symbiotic relationships between winter-adapted animals and their microbiota. [ABSTRACT FROM AUTHOR]

Aerobic degradation experiments of Triclosan were performed in activated sludge to identify possible transformation products for this compound. During 7 days, the formation of biotransformation products such as 2,4-Dichlorophenol, 4-Chlorocatechol, 5-Hydroxy-Triclosan and other Monohydroxy-Triclosan derivatives as well as Dihydroxy-Triclosan-derivatives were observed. The structure of 5-Hydroxy-Triclosan was elucidated by NMR data for the first time in sludge degradation experiments. Additionally the production of a hitherto unknown transformation product in sludge, i.e., Triclosan- O -Sulfate was detected. During the incubations, the concentrations of this transformation product changed from zero to 330 μg L − 1 . Based on the analysis of the biodegradation products, three types of reactions were identified: 1) chemical scission of ether bond to form phenols and catechols, 2) addition of OH moieties to the aromatic ring, and 3) adding of methyl or sulfate groups to the original hydroxyl group. [ABSTRACT FROM AUTHOR]

Summary: Microalgae comprise a phylogenetically very diverse group of photosynthetic unicellular pro‐ and eukaryotic organisms growing in marine and other aquatic environments. While they are well explored for the generation of biofuels, their potential as a source of antimicrobial and prebiotic substances have recently received increasing interest. Within this framework, microalgae may offer solutions to the societal challenge we face, concerning the lack of antibiotics treating the growing level of antimicrobial resistant bacteria and fungi in clinical settings. While the vast majority of microalgae and their associated microbiota remain unstudied, they may be a fascinating and rewarding source for novel and more sustainable antimicrobials and alternative molecules and compounds. In this review, we present an overview of the current knowledge on health benefits of microalgae and their associated microbiota. Finally, we describe remaining issues and limitation, and suggest several promising research potentials that should be given attention. [ABSTRACT FROM AUTHOR]

Using labelled-free proteomics, this study elucidates that the Enterobacter cloacae ECsp1 strain's response to tetrabromobisphenol A (TBBPA) exposure, revealing the degradation of the compound via cometabolism, which remodels the bacterial proteome. TBBPA is the dominant brominated flame retardant worldwide, but its degradation in wastewater plants remains poorly understood. Among the 531 identified proteins, 43 were up-regulated and 23 were down-regulated. Overexpressed proteins indicate that exposing this microorganism to the toxicant involves both up- and downregulation of enzymes involved in carbohydrate metabolism, genetic information processing, biosynthesis, cell maintenance, and xenobiotic degradation pathways. Evaluating the variation in protein abundance suggests degradation pathways related to: 1) the final steps of the glycolysis and alcohol fermentation in a cometabolism with glucose by phosphoglycerate mutase (PPM) and alcohol dehydrogenase (ADH) and 2) cleavage of the aromatic ring by carboxymuconolactone decarboxylase (CMD), specifically targeting benzoate and phenolic groups. The group of enzymes showing the widest variety of significantly upregulated proteins is related to xenobiotic transport elements (ABC transporters). Additionally, oxidative stress and envelope stress response are suggested by the upregulation of peroxidases and NlpE enzymes. Understanding dynamic changes in the protein expression sheds light on the metabolic mechanisms underlying TBBPA degradation during acidogenesis. [Display omitted] • Genome sequenced, yielding 1.79 Gbp, 97.5 % complete, classified as E. cloacae. • TBBPA was 99 % degraded in 4 h, Br− concentration reached 0.39 mg⋅L−1 after 8 h. • 531 proteins identified, 66 differentially expressed in presence of TBBPA. • Degradation mechanism: Glycolysis, alcohol fermentation, and CMD enzyme implicated. • Detoxification mechanisms: Upregulation of peroxidases and ABC transporters. [ABSTRACT FROM AUTHOR]

Abstract: The enhanced biological phosphorus removal (EBPR) process is increasingly popular as a sustainable method for removal of phosphorus (P) from wastewater. This study consisted of a comprehensive three-year investigation of the identity and population dynamics of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in 28 Danish municipal wastewater treatment plants with nutrient removal. Fluorescence in situ hybridization was applied to quantify ten probe-defined populations of PAO and GAO that in total constituted a large fraction (30% on average) of the entire microbial community targeted by the EUBmix probes. Two PAO genera, Accumulibacter and Tetrasphaera, were very abundant in all EBPR plants (average of 3.7% and 27% of all bacteria, respectively), and their abundance was relatively stable in the Danish full-scale plants without clear temporal variations. GAOs were occasionally present in some plants (Competibacter in 11 plants, Defluviicoccus in 6 plants) and were consistent in only a few plants. This shows that these were not core species in the EBPR communities. The total GAO abundance was always lower than that of Accumulibacter. In plants without EBPR design, the abundance of PAO and GAO was significantly lower. Competibacter correlated in general with high fraction of industrial wastewater. In specific plants Accumulibacter correlated with high C/P ratio of the wastewater and Tetrasphaera with high organic loading. Interestingly, the relative microbial composition of the PAO/GAO species was unique to each plant over time, which gives a characteristic plant-specific “fingerprint”. [Copyright &y& Elsevier]

Pigeon breeding is associated with symptoms of the airways. The aim of this study is to illuminate the bacteriological and toxicological characteristics of airborne dust in pigeon coops. Airborne dust was sampled in 31 urban pigeon coops with homing and fancy pigeons, and following the dust was characterized. In total 141 different bacterial species were identified using MALDI-TOF MS, and of these 11 species are classified in risk group 2. Of the cultivable bacteria, Staphylococcus equorum was present in the highest concentration. Microorganisms in the dust were able to form biofilm, and the amount correlated positively with the number of bacteria. Next generation sequencing showed 180 genera with Acinetobacter in highest reads. On average 999 ± 225 ZOTUs were observed per sample with a Shannon-Wiener biodiversity index of 6.17 ± 0.24. Of the identified species the following have previously been suggested as causative agents of extrinsic allergic alveolitis: Alcaligenes faecalis, Bacillus subtilis , Pantoea agglomerans , Sphingobacterium spiritivorum , Thermoactinomyces sp., and Streptomyces albus. Staphylococcus was present on particles with sizes between 1.1 and > 7.0 μm with a geometric mean diameter of particles on 4.7 ± 1.1 μm. Concentrations of airborne endotoxin and dust were elevated compared to references, and the geometric mean concentrations were 102 EU/m3 and 1.07 mg dust/m3, respectively. Upon exposure to the airborne dust human granulocytes produced Reactive Oxidative Species during the first 5 min, and then no further reaction was observed. The concentrations of bacteria in general, Staphylococcus spp., and endotoxin and biodiversity were associated significantly with season, temperature and/or relative humidity, but not with type or density of pigeons. The bacterial composition and biodiversity indices were not affected by type of pigeon. In conclusion, the exposure to bacteria and endotoxin in pigeon houses should not be neglected in the evaluation of causative agents of airways symptoms among pigeon breeders. [Display omitted] • Pigeons are bred in towns, breeders report health problems of the airway. • 84% of the 'pigeon coops' participate in international competitions. • Airborne bacterial species identified in 31 pigeon coops using NGS and/or MALDI-TOF. • Common genera were: Acinetobacter, Clostridium, Staphylococcus, Sphingobacterium. • Bacteria described as causative agents of allergic alveolitis were identified. [ABSTRACT FROM AUTHOR]

Bacterial biomass was characterised in supernatants from activated sludge from a nutrient removal plant after settling before and after applying gentle shear (G∼600s−1). Free-swimming and floc-associated bacteria were quantified by microscopy and their identity was determined by fluorescence in-situ hybridization (FISH). Total cell numbers in the supernatant after settling ranged within 2–9×107 cells/mL. Most cells (60–70%) were associated with microcolonies or small flocs, which made up 5–10% of the total number of particles. The remaining 30–40% of the cells corresponded to free-swimming, single cells. The small flocs in the supernatants (diameter=2.5–35μm) accounted only for ∼1% of the total number of particles; however, they greatly contributed to the total volume of biomass in suspension (57% and 75%). The shear applied (G∼600s−1) induced some floc detachment and higher cell numbers in the supernatants (10–70×107 cells/mL). The identity of bacteria in suspension was as diverse as that in the settled sludge; however, bacteria belonging to Planctomycetes, Firmicutes and Deltaproteobacteria were in higher abundance in the sludge supernatants and were enriched in the supernatants due to gentle shear. Potentially active bacteria were quantified based on the ratio of the number of cells fluorescing with the EUBmix gene probe targeting most bacteria to the total number of cells stained with DAPI. Lower ratios of EUBmix to total cells were measured in the supernatants (50%) than in the settled sludge (80%), suggesting that cells in the dispersed fraction of the sludge were potentially less active than those in the average settleable floc. In conclusion, the attachment properties of bacteria in activated sludge were different among groups, rendering floc fractions more susceptible to detachment and suspension depending on their abundance and activity level. [Copyright &y& Elsevier]

The article reports on the study conducted by the Department of Biotechnology, Chemistry and Environmental Engineering of the Aalborg University in Denmark on the structure and function of microbial community in a full-scale enhanced biological phosphorus removal wastewater treatment plant (EBPR WWTP). It uses a full-cycle rRna approach, combined with ecophysiological studies and a total of 87 16S rRNA gene sequence were retrieved and 78 operational taxonomic units were identified. Results show that Bacteriodetes were abundant in EBPR WWTPs and several novel abundant microbial groups that belong to Betaproteobacteria and Gammaproteobacteria were identified. It also shows that it is possible to detect most micro-organisms in full-scale EBPR WWTP using clone or group-specific gene probes.

Aims: Geosmin is associated with off‐flavour problems in recirculating aquaculture systems (RAS) and represents an economic problem for the aquaculture industry. This study aims at investigating factors influencing the composition of the bacterial microbiota, in particular the presence of geosmin producers and the environmental and farming factors favouring geosmin accumulation. Methods and Results: Several water quality parameters were correlated to the composition of the microbiota with special emphasis on the presence of geosmin producers within 26 different RAS from four European countries. Three novel groups of geosmin‐producing bacteria were quantified to identify potential correlations with geosmin concentration. Conclusions: The microbiome differed significantly between systems. However, phosphate levels, calcium levels and redox potential correlated to geosmin concentration in the water and the presence of the Actinomycetales geosmin‐producers but not with the presence of other groups of geosmin‐producing bacteria. Oxygen levels and conductivity were found to negatively correlate with geosmin concentration. A large proportion of the detected geosmin producers represented novel taxonomic groups not previously linked with this activity. Significance and Impact of the Study: These results improve our understanding of the diversity of microbiota in RAS and the water quality parameters favouring the populations of geosmin‐producing bacteria and the production of geosmin. [ABSTRACT FROM AUTHOR]

[Display omitted] • Anaerobic digestion of HTL process water was investigated over long-term. • Methane yields were lower for sewage sludge than for straw-manure mixtures. • The composition of HTL process water was a crucial factor in methane inhibition. • Microbial community shifts play a significant role in biogas production. • Mainly methanogens where inhibited, while fermenters were functionally redundant. Hydrothermal liquefaction (HTL) shows promise for converting wet biomass waste into biofuel, but the resulting high-strength process water (PW) requires treatment. This study explored enhancing energy recovery by anaerobic digestion using semi-batch reactors. Co-digesting manure with HTL-PW from wheat straw-manure co-HTL yielded methane (43–49% of the chemical oxygen demand, COD) at concentrations up to 17.8 gCOD·L-1, whereas HTL-PW from sewage sludge yielded methane (43% of the COD) up to only 12.8 gCOD·L-1 and complete inhibition occurred at 17 gCOD·L-1. Microbial community shifts confirmed inhibition of methanogenic archaea, while hydrolytic-fermentative bacteria were resilient. Differences in chemical composition, particularly higher levels of N-containing heterocyclic compounds in PW of sewage sludge, likely caused the microbial inhibition. The considerable potential of combining HTL with anaerobic digestion for enhanced energy recovery from straw-manure in an agricultural context is demonstrated, yet sewage sludge HTL-PW requires more advanced approaches to deal with methanogenesis inhibitors. [ABSTRACT FROM AUTHOR]

Feast-famine (FF) regimes improved the removal of recalcitrant pharmaceuticals in moving bed biofilm reactors (MBBRs), but the optimal FF cycle remained unresolved. The effects of FF cycle time on the removal of bulk substrates (organic carbon and nitrogen) and trace pharmaceuticals by MBBR are systematically evaluated in this study. The feast to famine ratio was fixed to 1:2 to keep the same loading rate, but the time for the FF cycles varied from 18 h to 288 h. The MBBR adapted to the longest FF cycle time (288 h equaling 48 × HRT) resulted in significantly higher degradation rates (up to +183%) for 12 out of 28 pharmaceuticals than a continuously fed (non-FF) reactor. However, other FF cycle times (18, 36, 72 and 144 h) only showed a significant up-regulation for 2–3 pharmaceuticals compared to the non-FF reactor. Enantioselective degradation of metoprolol and propranolol occurred in the second phase of a two phase degradation, which was different for the longer FF cycle time. N -oxidation and N -demethylation pathways of tramadol and venlafaxine differed across the FF cycle time suggestin the FF cycle time varied the predominant transformation pathways of pharmaceuticals. The abundance of bacteria in the biofilms varied considerably between different FF cycle times, which possibly caused the biofilm to remove more recalcitrant bulk organic C and pharmaceuticals under long cycle times. [Display omitted] • Feast famine (FF) cycle time affected MBBR performance. • The longest FF cycle time 288 h showed a higher removal for 12 pharmaceuticals. • Enantioselective degradation of metoprolol differed in FF and non-FF MBBRs. • Short FF cycle time led to higher denitrification, longer ones led to higher TOC removal. • FF cycle time changed the dominant bacteria in biofilm. [ABSTRACT FROM AUTHOR]

With an accelerating negative impact of anthropogenic actions on natural ecosystems, non-invasive biodiversity assessments are becoming increasingly crucial. As a consequence, the interest in the application of environmental DNA (eDNA) survey techniques has increased. The use of eDNA extracted from faeces from generalist predators, have recently been described as "biodiversity capsules" and suggested as a complementary tool for improving current biodiversity assessments. In this study, using faecal samples from two generalist omnivore species, the Eurasian badger and the red fox, we evaluated the applicability of eDNA metabarcoding in determining dietary composition, compared to macroscopic diet identification techniques. Subsequently, we used the dietary information obtained to assess its contribution to biodiversity assessments. Compared to classic macroscopic techniques, we found that eDNA metabarcoding detected more taxa, at higher taxonomic resolution, and proved to be an important technique to verify the species identification of the predator from field collected faeces. Furthermore, we showed how dietary analyses complemented field observations in describing biodiversity by identifying consumed flora and fauna that went unnoticed during field observations. While diet analysis approaches could not substitute field observations entirely, we suggest that their integration with other methods might overcome intrinsic limitations of single techniques in future biodiversity surveys. [ABSTRACT FROM AUTHOR]

• Microbial community of 18 food waste anaerobic digesters (AD) was characterised. • Temperature was one of the strongest drivers of microbial community structure. • Methanogens were influenced by a complex combination of operational conditions. • Food waste may promote AD robustness with diverse syntrophic microbes. • Potential usage of microbial data in food waste AD management is discussed. Anaerobic digestion of food waste is an attractive and increasingly popular technology within waste management and energy recovery. A better understanding of the microbiology associated with anaerobic digestion of food waste will provide new insight into the operational conditions required for optimizing this process, as well as its potential for utilisation in co-digestion systems. Eighteen full-scale reactors processing varying proportions of food waste under diverse operational configurations were subjected to microbial community analysis by amplicon sequencing of the 16S rRNA and mcrA genes to capture the bacterial and methanogenic populations. Statistical correlations between microbial populations, plant design and operating conditions revealed that the microbial communities were shaped by operational parameters such as the primary substrate type and operational temperature, while the methanogenic communities showed a more reactor specific distribution. The distribution of microbes based on the waste processed in the surveyed digesters was explored, as well as the presence of specialist populations such as syntrophs and methanogens. Food waste digester communities were not associated with a strong microbial fingerprint compared to other waste types (wastewater and manure) but contained greater abundance and unique syntrophic acetate oxidising populations, suggesting that co-digestion with food waste may improve the functional diversity of anaerobic digesters. [ABSTRACT FROM AUTHOR]

There is an increased interest in the possibility to use large animals in the restoration of degraded ecosystems and to increase the capacity of natural areas to sustain richer biodiversity. We quantify the dietary differences and similarities between five moose and 22 red deer introduced in a 2100 ha fenced area under restoration (Lille Vildmose, Denmark) and their potential in the restoration process. Moose and red deer were selected based on their biogeographic affinity and existing knowledge of their diet and feeding behaviour, and are expected to counteract encroachment on open habitats. Using eDNA metabarcoding of dung collected in the field and species identification through saliva recovered from browsed twigs, we investigated the species' diets and diet overlap after the moose were released into the area, and assessed how their diets match the expected ecosystem function. Despite the partial overlap of some dietary items, such as Betulaceae and Salicaceae, we report a differential use in height of tree species and distinctive use of other food resources between the two species, with red deer eating more herbaceous plants and the moose diet also containing aquatic plants. This study exemplifies a monitoring approach to restoration projects where large herbivores are expected to provide a key ecosystem function through their browsing and grazing. [ABSTRACT FROM AUTHOR]

Background: Houseflies (Musca domestica L.) live in intimate association with numerous microorganisms and is a vector of human pathogens. In temperate areas, houseflies will overwinter in environments constructed by humans and recolonize surrounding areas in early summer. However, the dispersal patterns and associated bacteria across season and location are unclear. We used genotyping-by-sequencing (GBS) for the simultaneous identification and genotyping of thousands of Single Nucleotide Polymorphisms (SNPs) to establish dispersal patterns of houseflies across farms. Secondly, we used 16S rRNA gene amplicon sequencing to establish the variation and association between bacterial communities and the housefly across farms. Results: Using GBS we identified 18,000 SNPs across 400 individuals sampled within and between 11 dairy farms in Denmark. There was evidence for sub-structuring of Danish housefly populations and with genetic structure that differed across season and sex. Further, there was a strong isolation by distance (IBD) effect, but with large variation suggesting that other hidden geographic barriers are important. Large individual variations were observed in the community structure of the microbiome and it was found to be dependent on location, sex, and collection time. Furthermore, the relative prevalence of putative pathogens was highly dependent on location and collection time. Conclusion: We were able to identify SNPs for the determination of the spatiotemporal housefly genetic structure, and to establish the variation and association between bacterial communities and the housefly across farms using novel next-generation sequencing (NGS) techniques. These results are important for disease prevention given the fine-scale population structure and IBD for the housefly, and that individual houseflies carry location specific bacteria including putative pathogens. [ABSTRACT FROM AUTHOR]

Ozone (O 3) treatment is an effective strategy in maintaining high efficiency and control of biomass accumulation in gas phase biofiltration. However, little is known about the long-term impact of O 3 on the microbial communities. In the present study, two biofilters treating gaseous ethyl acetate were operated continuously for 230 days with inlet loads up to 180 g m−3∙h−1. A biofilter operated under continuous O 3 addition (90 ppb v) yielded consistently higher removal efficiency (RE) and elimination capacity (EC) compared to the control system. After 120 days of operation, a lower biomass content accompanied by a pH of 1.5 was observed in the ozonated biofilter, which was 2 units lower compared to the control reactor. Both reactors developed a distinct microbial community composition over the course of 230 days. The bacterial community was dominated in both biofilters by Beijerinckia and Gluconacetobacter , while Rhinocladiella similis , Trichosporon veenhuissi and Exophilia oligosperma were abundant in the fungal community. These findings suggest that ozonation of the biofiltration systems not only reduced clogging, but also contributed to the selection of biomass suitable for degradation of ethyl acetate. • Continuous higher removal efficiency in the ozonated biofiltration system. • Biofiltration with ozone treatment resulted in more acidic operating conditions. • Distinct bacterial and fungal profile observed between ozonated and control system. • Ozonation contributed to biomass selection for ethyl acetate degradation. [ABSTRACT FROM AUTHOR]

The control of nitrite-oxidizing bacteria (NOB) challenges the implementation of partial nitritation and anammox (PN/A) processes under mainstream conditions. The aim of the present study was to understand how operating conditions impact microbial competition and the control of NOB in hybrid PN/A systems, where biofilm and flocs coexist. A hybrid PN/A moving-bed biofilm reactor (MBBR; also referred to as integrated fixed film activated sludge or IFAS) was operated at 15 °C on aerobically pre-treated municipal wastewater (23 mg NH4-N L−1). Ammonium-oxidizing bacteria (AOB) and NOB were enriched primarily in the flocs, and anammox bacteria (AMX) in the biofilm. After decreasing the dissolved oxygen concentration (DO) from 1.2 to 0.17 mg O2 L−1 - with all other operating conditions unchanged - washout of NOB from the flocs was observed. The activity of the minor NOB fraction remaining in the biofilm was suppressed at low DO. As a result, low effluent NO 3 − concentrations (0.5 mg N L−1) were consistently achieved at aerobic nitrogen removal rates (80 mg N L−1 d−1) comparable to those of conventional treatment plants. A simple dynamic mathematical model, assuming perfect biomass segregation with AOB and NOB in the flocs and AMX in the biofilm, was able to qualitatively reproduce the selective washout of NOB from the flocs in response to the decrease in DO-setpoint. Similarly, numerical simulations indicated that flocs removal is an effective operational strategy to achieve the selective washout of NOB. The direct competition for NO 2 − between NOB and AMX - the latter retained in the biofilm and acting as a "NO 2 -sink" - was identified by the model as key mechanism leading to a difference in the actual growth rates of AOB and NOB (i.e. , μ NOB < μ AOB in flocs) and allowing for the selective NOB washout over a broad range of simulated sludge retention times (SRT = 6.8–24.5 d). Experimental results and model predictions demonstrate the increased operational flexibility, in terms of variables that can be easily controlled by operators, offered by hybrid systems as compared to solely biofilm systems for the control of NOB in mainstream PN/A applications. Image 1 • Hybrid PN/A systems provide increased operational flexibility for NOB control • AOB and NOB enrich primarily in the flocs, and AMX in the biofilm ("NO 2 -sink") • AMX use NO 2 − allowing to differentiate AOB and NOB growth rates • A decrease in DO or an increase in floc removal leads to selective NOB washout from flocs • The activity of the minor NOB fraction in the biofilm is suppressed at limiting DO [ABSTRACT FROM AUTHOR]

Abstract Regular monitoring of the microbiome in recirculated aquaculture systems will allow the farmer to link water quality parameters to subsequent fish performance and will function as a tool for early identification of microbial conditions that could lead to impaired fish health. Microbial communities were monitored in different compartments of a commercial full-scale, land-based saltwater RAS for production of Atlantic salmon during 9 months. The microbial communities revealed a unique composition in the production tanks and moving bed biofilters, as compared to the other investigated compartments. The fixed bed compartment had a higher stability in the microbial community over time, relative to the moving bed biofilter compartment. Changes of the operation of the facility (replenishment of brackish water to seawater) caused an immediate shift in the microbial populations. Potential geosmin producers (bacteria harbouring the functional gene for geosmin synthetase geoA) were dominated by Sorangium , Actinomycetales and Myxococcales, but unidentified microorganisms harbouring the geoA gene were also present. The biofilters had the highest numbers of potential geosmin producers, but their presence did not co-vary with the levels of geosmin. This suggest that an observed period with high levels geosmin were due to a change in activity, rather than an increase in cell numbers. Our results provide new insight into the diversity of microbiota in RAS and suggest that monitoring of microbial communities in the aquaculture production may provide a tool for future microbial management to ensure stability in RAS performance. Highlights • Microbial communities were monitored over nine months in a full-scale saltwater RAS for salmon production • Sorangium, Actinomycetales and Myxococcales were dominant geosmin producers but unidentified geosmin-producing bacteria were also present • Lack of correlation between potential geosmin producers and geosmin levels suggests variations in cell activity • Microbial communities reflects changes in operation and thus indicates microbial management as a future tool in aquaculture [ABSTRACT FROM AUTHOR]

• Biofilm thickness influences activity of phosphate accumulation organisms (PAO). • Maximal PAO activity in biofilms of 100–500 µm. • Acetate consuming bacteria outcompete PAO in thinner biofilms of 30–100 µm. • Mass transfer limitation limits PAO activity in thicker biofilms of 500–1000 µm. • Higher volumetric P removal rates in biofilm-based than conventional systems. Can biofilms enhance the rates of phosphorus removal in wastewater treatment? In order to narrow the scientific gap on the effect of biofilm thickness on the activity and microbial community of phosphorus-accumulating bacteria, this study investigated biofilms of 30 to 1000 µm thickness in a moving bed biofilm reactor. Measurements on 5 different biofilm carriers showed that biomass-specific phosphorus release and uptake rates increased as a function of biofilm thickness for biofilms thinner than about 110 µm but were lower for thicker biofilms of about 550–1000 µm. The reduced phosphorus uptake and release rates in the thickest biofilms can result from substrate mass transfer limitations whereas the low activity in the thinnest biofilms can be related to a too high turnover rate in the biofilm due to heterotrophic growth. Additionally, the microbial ecology of the different biofilms confirms the observed phosphorus uptake and release rates. The results from the full-length 16S rRNA gene sequencing of the bacterial community showed that the thicker biofilms were characterized by higher relative abundance (40–58%) of potential phosphorus accumulating genera Zoogloea, Acinetobacter, Dechloromonas and Ca. Accumulibacter. In contrast, the thinner biofilms were dominated by the genus Ferribacterium (34–60%), which might be competing with phosphorus-accumulating bacteria as indicated by the relatively high acetate uptake rates in the thinner biofilms. It is concluded that there is an optimal biofilm thickness of 100–500 µm, at which the phosphorus accumulating bacteria have the highest activity. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • 13C from PBAT monomers was tracked under anaerobic and thermophilic conditions. • 1,4-butanediol and adipic acid were assimilated in the biomass. • 3 genera were able to directly metabolise at least 1 of the 3 PBAT monomer units. • A HQ-MAG was identified as A. thermophila and as an active degrader of butanediol. PBAT (poly butylene adipate-co-terephthalate) is a widely used biodegradable plastic, but the knowledge about its metabolization in anaerobic environments is very limited. In this study, the anaerobic digester sludge from a municipal wastewater treatment plant was used as inoculum to investigate the biodegradability of PBAT monomers in thermophilic conditions. The research employs a combination of 13C-labelled monomers and proteogenomics to track the labelled carbon and identify the microorganisms involved. A total of 122 labelled peptides of interest were identified for adipic acid (AA) and 1,4-butanedio (BD). Through the time-dependent isotopic enrichment and isotopic profile distributions, Bacteroides , Ichthyobacterium , and Methanosarcina were proven to be directly involved in the metabolization of at least one monomer. This study provides a first insight into the identity and genomic potential of microorganisms responsible for biodegradability of PBAT monomers during anaerobic digestion under thermophilic conditions. [ABSTRACT FROM AUTHOR]

A tiered process was developed to assess the transformation, CO 2 formation and uptake of four organic micropollutants by carrier-attached microorganisms from two municipal wastewater treatment plants. At the first tier, primary transformation of ibuprofen, naproxen, diclofenac, and mecoprop by carrier-attached microorganisms was shown by the dissipation of the target compounds and the formation of five transformation products using LC-tandem MS. At the second tier, the microbial cleavage of the four organic micropollutants was confirmed with 14 C-labeled micropollutants through liquid scintillation counting of the 14 CO 2 formed. At the third tier, microautoradiography coupled with fluorescence in situ hybridization (MAR-FISH) was used to screen carrier-attached microorganisms for uptake of the four radiolabeled micropollutants. Results from the MAR-FISH screening indicated that only a small fraction of the microbial community (≤1‰) was involved in the uptake of the radiolabeled micropollutants and that the responsible microorganisms differed between the compounds. At the fourth tier, the microbial community structure of the carrier-attached biofilms was analyzed by 16S rRNA gene amplicon sequencing. The sequencing results showed that the MAR-FISH screening targeted ∼80% of the microbial community and that several taxonomic families within the FISH-probed populations with MAR-positive signals (i.e. Firmicutes , Gammaproteobacteria , and Deltaproteobacteri a) were present in both biofilms. From the broader perspective of organic micropollutant removal in biological wastewater treatment, the MAR-FISH results of this study indicate a high degree of microbial substrate specialization that could explain differences in transformation rates and patterns between micropollutants and microbial communities. [ABSTRACT FROM AUTHOR]