Plastic-degrading microbial communities reveal novel microorganisms, pathways, and biocatalysts for polymer degradation and bioplastic production.

Plastics derived from fossil fuels are used ubiquitously owing to their exceptional physicochemical characteristics. However, the extensive and short-term use of plastics has caused environmental challenges. The biotechnological plastic conversion can help address the challenges related to plastic pollution, offering sustainable alternatives that can operate using bioeconomic concepts and promote socioeconomic benefits. In this context, using soil from a plastic-contaminated landfill, two consortia were established (ConsPlastic-A and -B) displaying versatility in developing and consuming polyethylene or polyethylene terephthalate as the carbon source of nutrition. The ConsPlastic-A and -B metagenomic sequencing, taxonomic profiling, and the reconstruction of 79 draft bacterial genomes significantly expanded the knowledge of plastic-degrading microorganisms and enzymes, disclosing novel taxonomic groups associated with polymer degradation. The microbial consortium was utilized to obtain a novel Pseudomonas putida strain (BR4), presenting a striking metabolic arsenal for aromatic compound degradation and assimilation, confirmed by genomic analyses. The BR4 displays the inherent capacity to degrade polyethylene terephthalate (PET) and produce polyhydroxybutyrate (PHB) containing hydroxyvalerate (HV) units that contribute to enhanced copolymer properties, such as increased flexibility and resistance to breakage, compared with pure PHB. Therefore, BR4 is a promising strain for developing a bioconsolidated plastic depolymerization and upcycling process. Collectively, our study provides insights that may extend beyond the artificial ecosystems established during our experiments and supports future strategies for effectively decomposing and valorizing plastic waste. Furthermore, the functional genomic analysis described herein serves as a valuable guide for elucidating the genetic potential of microbial communities and microorganisms in plastic deconstruction and upcycling.

Protective effect of Agaricus bisporus mushroom against maternal and fetal damage induced by lead administration during pregnancy in rats.

INTRODUCTION: Lead (Pb) is a toxic pollutant, which can affect different tissues of the human body. The use of natural elements, as medicinal mushroom can reduce the toxic effects of Pb. OBJECTIVE: We evaluated, through preclinical tests, the oral co exposures to mushroom Agaricus bisporus (Ab) by gavage and Pb in drinking water, and the capability of Ab be a protective agent for both pregnant rats and their fetuses. METHODS: Female Wistar rats were divided into four groups (n = 5/group): Group I-Control; Group II-Ab 100 mg/kg; Group III-Pb 100 mg/L; Group IV-Ab +Pb -100 mg/kg +100 mg/L. Exposure was performed until the 19th day of gestation. On the 20th day, pregnant rats were euthanized, and the outcomes evaluated were weight gain; hematological profile; biochemical markers; oxidative stress markers; reproductive capacity; and embryo fetal development. RESULTS: The characterization of mushrooms reveals them to be a valuable source of nutrients. However, Pb ingestion resulted in reduced weight gain and negative impacts on hematological and biochemical parameters. Fortunately, co administration of mushrooms helped to mitigate these negative effects and promote recovery. The mushroom also showed antioxidant activity, improving parameters of oxidative stress. In addition, Ab partially recovered the damage in fetal morphology and bone parameters. CONCLUSION: Our findings indicated that the co administration of Ab improved the toxicity caused by Pb, and the mushroom could be used as a natural alternative as a protective/chelator agent.

Biosorption of pharmaceutical products by mushroom stem waste.

Residues from pharmaceutical products are found in effluents and in other environmental matrices such as soil and surface waters. Chitin and chitosan are highly adsorptive substances present in mushrooms such as champignon (Agaricus bisporus) and shiitake (Lentinula edodes). This study evaluated the adsorption efficiency of shiitake and champignon stalks, and shiitake substrate in water contaminated with paracetamol and 17 α-ethynyl estradiol (EE2). Stalks and substrate were dried and ground. Particles were physically evaluated and chemically characterized. Adsorption kinetic and isotherms were carried out for EE2 and paracetamol. Shiitake and champignon stalks had high percentage of porosity, closed and open pores. All bioproducts from mushroom had chemical groups similar to chitosan standard. However, the degree of deacetylation of chitosan was higher in shiitake (28.3%). In EE2 adsorption kinetics, shiitake and champignon stalks showed 100% removal in 20 and 30 min, respectively. Shiitake substrate showed 80% removal. In paracetamol adsorption kinetics, all bioproducts presented more than 95% removal. In EE2 adsorption isotherm, the maximum adsorption capacities (qmax) to shiitake and champignon stalks and shiitake substrate were 5.62, 18.95 and 0.31 mgEE2/g, respectively. For paracetamol adsorption isotherm, qmax to shiitake and champignon stalks were 34.20 and 338.08 mgparacetamol/g, respectively. In conclusion, shiitake and champignon stalks (specially champignon) had the best results regarding the adsorption of EE2 and paracetamol. Reuse of discarded mushroom waste reduces the environmental impact and can add value to the product.

Development and evaluation of a floating multiparticulate gastroretentive system for modified release of AZT.

The aim of this study was to develop and evaluate a floating multiparticulate gastroretentive system for the modified release of zidovudine (AZT). AZT was used as a model drug water-soluble at therapeutic doses. The floating gastroretentive system was obtained by co-precipitation, after solvent diffusion and evaporation. The proposed system was evaluated in vitro for particle morphology, lag time and floating time, loading rate, release profile, and the release kinetic of AZT release. AZT's physico-chemical characteristics were evaluated by differential scanning calorimetry (DSC), X-ray diffraction (XDR) and infrared spectroscopy (IR). The particles obtained were sphere-shaped, hollow, and had porous walls. The floating was immediate, and floating time was higher than 12 h. The loading rate was 34.0 ± 9.0%. The system obtained had an extended release. DSC and XDR results showed a modification in AZT's solid state. IR spectroscopy revealed that the chemical structure of the AZT was unchanged. The hollow microballoons presented gastroretentive, floating, and extended-release properties.