Biodegradation of untreated plasticizers-free linear low-density polyethylene films by marine bacteria.

Polyethylene significantly contributes to marine plastic pollution. This study focuses on isolating bacteria from sea water and microplastic samples collected from the Tyrrhenian Sea and evaluating their ability to degrade virgin plasticizers-free linear low-density polyethylene (LLDPE) films. The isolates grew on the plastic film under aerobic conditions in shaken flasks leading to LLDPE mass losses of up to 2.

Maize ( L.) Plants Alter the Fate and Accumulate Nonextractable Residues of Sulfamethoxazole in Farmland Soil.

The fate of sulfonamide antibiotics in farmlands is crucial for food and ecological safety, yet it remains unclear. We used [phenyl-U-C]-labeled sulfamethoxazole (C-SMX) to quantitatively investigate the fate of SMX in a soil-maize system for 60 days, based on a six-pool fate model. Formation of nonextractable residues (NERs) was the predominant fate for SMX in unplanted soil, accompanied by minor mineralization.

Pollutant profile complexity governs wastewater removal of recalcitrant pharmaceuticals.

Organic pollutants are an increasing threat for wildlife and humans. Managing their removal is however complicated by the difficulties in predicting degradation rates. In this work, we demonstrate that the complexity of the pollutant profile, the set of co-existing contaminants, is a major driver of biodegradation in wastewater.

Analyzing microbial communities and their biodegradation of multiple pharmaceuticals in membrane bioreactors.

Pharmaceuticals are of concern to our planet and health as they can accumulate in the environment. The impact of these biologically active compounds on ecosystems is hard to predict, and information on their biodegradation is necessary to establish sound risk assessment. Microbial communities are promising candidates for the biodegradation of pharmaceuticals such as ibuprofen, but little is known yet about their degradation capacity of multiple micropollutants at higher concentrations (100 mg/L).

[Insights into the applications of 3D bioprinting for bioremediation technologies].

A plethora of organic pollutants such as pesticides, polycyclic and halogenated aromatic hydrocarbons, and emerging pollutants, such as flame retardants, is continuously being released into the environment. This poses a huge threat to the society in terms of environmental pollution, agricultural product quality, and general safety. Therefore, effective removal of organic pollutants from the environment has become an important challenge to be addressed.

Living with sulfonamides: a diverse range of mechanisms observed in bacteria.

Sulfonamides are the oldest class of synthetic antibiotics still in use in clinical and veterinary settings. The intensive utilization of sulfonamides has been leading to the widespread contamination of the environment with these xenobiotic compounds. Consequently, in addition to pathogens and commensals, also bacteria inhabiting a wide diversity of environmental compartments have been in contact with sulfonamides for almost 90 years.

Subsistence and complexity of antimicrobial resistance on a community-wide level.

There are a multitude of resistance strategies that microbes can apply to avoid inhibition by antimicrobials. One of these strategies is the enzymatic modification of the antibiotic, in a process generally termed inactivation. Furthermore, some microorganisms may not be limited to the mere inactivation of the antimicrobial compounds.

Comparative genomics reveals a novel genetic organization of the sad cluster in the sulfonamide-degrader 'Candidatus Leucobacter sulfamidivorax' strain GP.

Background: Microbial communities recurrently establish metabolic associations resulting in increased fitness and ability to perform complex tasks, such as xenobiotic degradation. In a previous study, we have described a sulfonamide-degrading consortium consisting of a novel low-abundant actinobacterium, named strain GP, and Achromobacter denitrificans PR1. However, we found that strain GP was unable to grow independently and could not be further purified.

Biodegradation of antibiotics: The new resistance determinants - part II.

Antibiotic residues are widespread in the environment and their presence is known to contribute to the propagation of antibiotic resistance. Nevertheless, knowledge on processes involved in their degradation is scattered. This second part of a two part review aims at compiling knowledge on the (bio-) degradation of antibiotics, focusing on β-lactams, macrolides, quinolones and ionophores, as well as some less common classes.

Biodegradation of antibiotics: The new resistance determinants - part I.

History shows that the discovery of, and the resistance to, antibiotics go hand in hand. While knowledge of resistance mechanisms, their impact and distribution is vast, over the years, the topic of antibiotic degradation has often been overlooked and regarded as being discrete from the research on resistance. As a result, understanding of the degradation of antibiotics and the impact of antibiotic degraders on the environment and human health are, for most classes, neither thoroughly documented nor understood.

Biodegradation of mixture of plastic films by tailored marine consortia.

This work sheds light on the physicochemical changes of naturally weathered polymer surfaces along with changes of polymer buoyancy due to biofilm formation and degradation processes. To support the degradation hypothesis, a microcosm experiment was conducted where a mixture of naturally weathered plastic pieces was incubated with an indigenous pelagic community. A series of analyses were employed in order to describe the alteration of the physicochemical characteristics of the polymer (FTIR, SEC and GPC, sinking velocity) as well as the biofilm community (NGS).

Biodegradation of sulfamethoxazole by a bacterial consortium of Achromobacter denitrificans PR1 and Leucobacter sp. GP.

In the last decade, biological degradation and mineralization of antibiotics have been increasingly reported feats of environmental bacteria. The most extensively described example is that of sulfonamides that can be degraded by several members of Actinobacteria and Proteobacteria. Previously, we reported sulfamethoxazole (SMX) degradation and partial mineralization by Achromobacter denitrificans strain PR1, isolated from activated sludge.

Towards an affordable enzymatic production of biopolyols - Comparing the immobilization of lipases by two optimized techniques.

The production of biopolyols (sustainable, renewable and biodegradable precursors), is exclusively focused on the conventional chemical synthesis pathways, and currently, no polyols are produced by enzymatic processes at an industrial scale, because they are not competitive when compared to petrochemically based polyols due to the overall cost for their production. This can be mainly attributed to the high costs of commercial enzymes used in this process and their use is limited by their lack of stability during the bioprocess. Immobilization of enzymes gives the opportunity to converge two important features of enzymes: to increase the protein stability and to reuse enzyme as a catalyst.

Biotransformation of Sulfonamide Antibiotics in Activated Sludge: The Formation of Pterin-Conjugates Leads to Sustained Risk.

The presence of antibiotics in treated wastewater and consequently in surface and groundwater resources raises concerns about the formation and spread of antibiotic resistance. Improving the removal of antibiotics during wastewater treatment therefore is a prime objective of environmental engineering. Here we obtained a detailed picture of the fate of sulfonamide antibiotics during activated sludge treatment using a combination of analytical methods.

Biodegradation of weathered polystyrene films in seawater microcosms.

A microcosm experiment was conducted at two phases in order to investigate the ability of indigenous consortia alone or bioaugmented to degrade weathered polystyrene (PS) films under simulated marine conditions. Viable populations were developed on PS surfaces in a time dependent way towards convergent biofilm communities, enriched with hydrocarbon and xenobiotics degradation genes. Members of Alphaproteobacteria and Gammaproteobacteria were highly enriched in the acclimated plastic associated assemblages while the abundance of plastic associated genera was significantly increased in the acclimated indigenous communities.

FMNH-dependent monooxygenases initiate catabolism of sulfonamides in Microbacterium sp. strain BR1 subsisting on sulfonamide antibiotics.

We report a cluster of genes encoding two monooxygenases (SadA and SadB) and one FMN reductase (SadC) that enable Microbacterium sp. strain BR1 and other Actinomycetes to inactivate sulfonamide antibiotics. Our results show that SadA and SadC are responsible for the initial attack of sulfonamide molecules resulting in the release of 4-aminophenol.

Development of tailored indigenous marine consortia for the degradation of naturally weathered polyethylene films.

This study investigated the potential of bacterial-mediated polyethylene (PE) degradation in a two-phase microcosm experiment. During phase I, naturally weathered PE films were incubated for 6 months with the indigenous marine community alone as well as bioaugmented with strains able to grow in minimal medium with linear low-density polyethylene (LLDPE) as the sole carbon source. At the end of phase I the developed biofilm was harvested and re-inoculated with naturally weathered PE films.

Complete Genome Sequence of PR1.

strain PR1 was isolated from an enrichment culture able to use sulfamethoxazole as an energy source. Here, we describe the complete genome of this strain sequenced by Illumina MiSeq and Oxford Nanopore MinION.

Isolation of two Ochrobactrum sp. strains capable of degrading the nootropic drug-Piracetam.

Piracetam (2-oxo-1-pyrrolidine acetamide) is a popular cognitive enhancer, which has recently been detected in waste and drinking water. Nootropic drugs are designed to affect human metabolism and act on the nervous system, but their environmental effects have yet to be the subject of detailed studies. In this report, we present the efficient biodegradation of the cognitive enhancer, piracetam.

Formation, characterization, and mineralization of bound residues of tetrabromobisphenol A (TBBPA) in silty clay soil under oxic conditions.

The nature and stability of bound residues (BRs) derived from the widely used brominated flame retardant tetrabromobisphenol A (TBBPA) in fine-textured soil is unknown. We incubated C-labeled TBBPA in silty clay rice paddy soil for 93days under oxic conditions. TBBPA dissipated with a first-order kinetic constant k of 0.

The crystal structures of native hydroquinone 1,2-dioxygenase from Sphingomonas sp. TTNP3 and of substrate and inhibitor complexes.

The crystal structure of hydroquinone 1,2-dioxygenase, a Fe(II) ring cleaving dioxygenase from Sphingomonas sp. strain TTNP3, which oxidizes a wide range of hydroquinones to the corresponding 4-hydroxymuconic semialdehydes, has been solved by Molecular Replacement, using the coordinates of PnpCD from Pseudomonas sp. strain WBC-3.

Arsenic Mobilization from Historically Contaminated Mining Soils in a Continuously Operated Bioreactor: Implications for Risk Assessment.

Concentrations of soil arsenic (As) in the vicinity of the former Złoty Stok gold mine (Lower Silesia, southwest Poland) exceed 1000 μg g(-1) in the area, posing an inherent threat to neighboring bodies of water. This study investigated continuous As mobilization under reducing conditions for more than 3 months. In particular, the capacity of autochthonic microflora that live on natural organic matter as the sole carbon/electron source for mobilizing As was assessed.

Mineralisation of C-labelled polystyrene plastics by Penicillium variabile after ozonation pre-treatment.

Large amounts of polystyrene (PS), one of the most widely used plastics in the world, end up in the environment through industrial discharge and littering, becoming one of the major components of plastic debris. Such plastics, especially the small-sized microplastics and nanoplastics, have received increasing concerns in terms of their potential environmental risks. Feasible approaches for the degradation of PS in waste materials and in the environment are highly desirable.

Fate of Tetrabromobisphenol A (TBBPA) and Formation of Ester- and Ether-Linked Bound Residues in an Oxic Sandy Soil.

Bound-residue formation is a major dissipation process of most organic xenobiotics in soil. However, both the formation and nature of bound residues of tetrabromobisphenol A (TBBPA) in soil are unclear. Using a 14C-tracer, we studied the fate of TBBPA in an oxic soil during 143 days of incubation.

Ipso-substitution--the hidden gate to xenobiotic degradation pathways.

Screening for metabolites of environmental pollutants, the focus is often on transformation products based on well-known pathways. Hydroxylation at unsubstituted positions of the aromatic ring or side chain modifications, followed by meta ring-cleavage pathways are usually considered, whereas less obvious mechanisms are often ignored. Here, a glimpse of the multitude of transformations involving ipso-substitution events, which are often overlooked as such, is presented.