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A new degradation pathway of the bisphenol A was investigated. Results concluded that the degradation of bisphenol A is initiated by monooxygenase that may also lead to ipso substitution in other xenobiotics containing phenol with a quaternary [alpha]-carbon.

The wide application of sulfonamide (SA) antibiotics in human and veterinary medicine contributes to the accumulation of these antibiotics in the environment and the corresponding onset of antibiotic resistance among bacteria. Microbacterium sp. BR1 is capable of mineralizing sulfamethoxazole and other SAs via a novel mechanism. The genetic basis of SA elimination by BR1 remains unknown. Development of an efficient plasmid transfer protocol for Microbacterium sp. BR1 is highly desirable, as it would open the door to genetic analysis and manipulation of its genome. Here we report that intergeneric Escherichia coli–Microbacterium spp. BR1 conjugation is an efficient way to introduce various plasmids into BR1. The generated transconjugants were stable in the presence of antibiotics and the plasmids showed no signs of rearrangements. Nevertheless, the plasmids were rapidly lost in the absence of selection. We also show that the cumate-inducible beta-glucuronidase reporter gene functions in BR1 and is strictly regulated. Our results set the working ground for further genetic manipulations of BR1, such as the overexpression of sulfonamide degradation genes or the selection of strong microbacterial promoters. [ABSTRACT FROM AUTHOR]

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 2.597 ± 0.971 % after 60 days incubation. Biofilm formation on the film surface was confirmed by adhered protein quantification while film surface erosion and appearance of functional groups were revealed using SEM and FTIR analyses confirming biodegradation capabilities especially for isolates Bacillus velezensis MT9, Vreelandella venusta MT1 and Vreelandellatitanicae MT11. This is the first report on the biodegradation of plasticizers-free non pretreated LLDPE films by marine Bacillus sp. and Vreelandella sp.; most of the LLDPE biodegradation studies have been so far performed on plasticizer containing, pre-treated, or naturally weathered films., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

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. As a consequence of the recent and rapid developments in additive manufacturing, 3D bioprinting technology is playing an important role in the pharmaceutical industry. At the same time, an increasing number of microorganisms suitable for the production of biomaterials with complex structures and functions using 3D bioprinting technology, have been identified. This article briefly discusses the principles, advantages, and disadvantages of different 3D bioprinting technologies for pollutant removal. Furthermore, the feasibility and challenges of developing bioremediation technologies based on 3D bioprinting have also been discussed.

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). At the end of phase II, the fraction of double bonds in the surface of microbially treated PE films increased while changes were also observed in the profile of the PS films. The molecular weight of PE pieces increased with incubation time reaching the molecular weight of the virgin pieces (230,000 g mol -1 ) at month 5 but the buoyancy displayed no difference throughout the experimental period. The number-average molecular weight of PS pieces decreased (33% and 27% in INDG and BIOG treatment respectively), implying chain scission; accelerated (by more than 30%) sinking velocities compared to the initial weathered pieces were also measured for PS films with biofilm on their surface. The orders Rhodobacterales, Oceanospirillales and Burkholderiales dominated the distinct platisphere communities and the genera Bacillus and Pseudonocardia discriminate these assemblages from the planktonic counterpart. The functional analysis predicts overrepresentation of adhesive cells carrying xenobiotic and hydrocarbon degradation genes. Taking these into account, we can suggest that tailored marine consortia have the ability to thrive in the presence of mixtures of plastics and participate in their degradation., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

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. By this study, we were aiming to explore alternatives to commercially available enzymes. We investigated an effective hydrolytic route from epoxidized oils to polyols by applying lipolytic enzymes from Yarrowia lipolytica and Candida cylindracea immobilized onto fumed silica nanoparticles (fsNP) and those immobilized by the formation of cross-linked enzyme aggregates (CLEAs). Oxirane ring hydrolysis of epoxidized rapeseed oil catalyzed by lipase-fsNP and CLEAs was investigated with respect to various parameters (temperature, pH, concentrations, time of sorption and cross-linking, etc.). The highest conversions for oxirane ring hydrolysis were estimated for CLEA-Lip-derivatives (45-56%)., (Copyright © 2018 Elsevier B.V. All rights reserved.)

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. Two bacterial strains capable of using this compound as the sole carbon source were isolated and later identified as Ochrobactrum anthropi strain MW6 and Ochrobactrum intermedium strain MW7. The compound's mineralization and the cleavage of the heterocyclic ring were shown in the experiments with 14 C-labeled piracetam. This is also the first report of a pharmaceutical's degradation by the Ochrobactrum genus. This study presents model microorganisms that can be used in further investigation of piracetam's degradation pathways as well as enzymes and genes involved in the process., (Copyright © 2017 Elsevier B.V. All rights reserved.)

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. Both tailored consortia efficiently reduced the weight of PS films. Concerning the molecular weight distribution, a decrease in the number-average molecular weight of films subjected to microbial treatment was observed. Moreover, alteration in the intensity of functional groups was noticed with Fourier transform infrared spectrophotometry (FTIR) along with signs of bio-erosion on the PS surface. The results suggest that acclimated marine populations are capable of degrading weathered PS pieces.

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. Physicochemical pretreatments of PS may be applied to enhance biological degradation. In the present study, we synthesized 14 C-labelled PS polymers, either uniformly labelled on the ring ([U-ring- 14 C]-PS) or labelled at the β-carbon position of the alkyl chain ([β- 14 C]-PS), and investigated the mineralisation of the 14 C-PS polymers by the fungus Penicillium variabile CCF3219 as well as the effect of ozonation as a physico-chemical pre-treatment on the mineralisation by the fungi. Biodegradation of the 14 C-PS polymers was studied in liquid medium (pH 7.5, without additional carbon substrate) with P. variabile for 16 weeks. During the incubation time, 14 CO 2 was captured to calculate the mineralisation of 14 C-PS and the remaining polymers were analysed by means of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectrometry and gel-permeation chromatography (GPC). The results showed that the fungi mineralised both labelled polymers, and that the [U-ring- 14 C]-PS with a lower molecular weight led to a higher mineralisation rate. Ozonation pre-treatment strongly enhanced mineralisation of [β- 14 C]-PS. SEM analysis showed that the surface of the ozonated [β- 14 C]-PS became uneven and rough after the incubation, indicating an attack on the polymer by P. variabile. FT-IR analysis showed that ozonation generated carbonyl groups on the [β- 14 C]-PS and the amount of the carbonyl groups decreased after incubation of the [β- 14 C]-PS with P. variabile. GPC analysis showed that the molecular weights of the ozonated [β- 14 C]-PS decreased after incubation. The present data suggest that ozonation pretreatment could be a potential approach for degradation of PS waste and remediation of PS-contaminated sites., (Copyright © 2016 Elsevier B.V. All rights reserved.)

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. Bacteria from both treatments were able to establish an active population on the PE surfaces as the biofilm community developed in a time dependent way. Moreover, a convergence in the composition of these communities was observed towards an efficient PE degrading microbial network, comprising of indigenous species. In acclimated communities, genera affiliated with synthetic (PE) and natural (cellulose) polymer degraders as well as hydrocarbon degrading bacteria were enriched. The acclimated consortia (indigenous and bioaugmented) reduced more efficiently the weight of PE films in comparison to non-acclimated bacteria. The SEM images revealed a dense and compact biofilm layer and signs of bio-erosion on the surface of the films. Rheological results suggest that the polymers after microbial treatment had wider molecular mass distribution and a marginally smaller average molar mass suggesting biodegradation as opposed to abiotic degradation. Modifications on the surface chemistry were observed throughout phase II while the FTIR profiles of microbially treated films at month 6 were similar to the profiles of virgin PE. Taking into account the results, we can suggest that the tailored indigenous marine community represents an efficient consortium for degrading weathered PE plastics.

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. TBBPA dissipated with a half-life of 14.7 days; at the end of incubation, 19.6% mineralized and 66.5% formed bound residues. Eight extractable metabolites were detected, including TBBPA methyl ethers, single-ring bromophenols, and their methyl ethers. Bound residues (mostly bound to humin) rapidly formed during the first 35 days. The amount of those humin-bound residues then quickly decreased, whereas total bound residues decreased slowly. By contrast, residues bound to humic acids and fulvic acids increased continuously until a plateau was reached. Ester- and ether-linked residues accounted for 9.6-27.0% of total bound residues during the incubation, with ester linkages being predominant. Residues bound via ester linkages consisted of TBBPA, TBBPA monomethyl ether, and an unknown polar compound. Our results indicated that bound-residue formation is the major pathway of TBBPA dissipation in oxic soil and provide first insights into the chemical structure of the reversibly ester-linked bound residues of TBBPA and its metabolites.

Over the past seven years, we have been working with Sphingomonas sp. strain TTNP3, a bacterium capable of growing on numerous alkylphenolic compounds as a source of carbon and energy. We succeeded in elucidating an unusual pathway involving an attack at the quaternary alpha-carbon atom of the substrate, a position previously thought to be highly resistant to biodegradation. Combining analytical and bioanalytical methods, a good understanding of the reaction mechanisms, the enzymes catalysing them and the organization of the genes encoding them could be gained. First studies on the use of Sphingomonas sp. strain TTNP3 in wastewater treatment have been performed revealing promising results., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Selenium-reducing microorganisms produce elemental selenium nanoparticles with particular physicochemical properties due to an associated organic fraction. This study identified high-affinity proteins associated with such bionanominerals and with nonbiogenic elemental selenium. Proteins with an anticipated functional role in selenium reduction, such as a metalloid reductase, were found to be associated with nanoparticles formed by one selenium respirer, Sulfurospirillum barnesii.