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Bisphenol A (BPA) is a synthetic xenoestrogen diffused worldwide. Humans are chronically exposed to low doses of BPA from food and drinks, thus BPA accumulates in tissues posing human health risk. In this study, we investigated the effects of BPA on peripheral blood mononuclear cells (PBMC) from human healthy donors, and in glia and microglia of rat offspring at postnatal day 17 (17PND) from pregnant females who received BPA soon after coupling and during lactation and weaning. Results indicated that BPA affected Phytoemagglutinin (PHA) stimulated PBMC proliferation causing an S-phase cell cycle accumulation at nanomolar concentrations while BPA was almost ineffective in resting PBMC. Furthermore, BPA induced chromosome aberrations and the appearance of shattered cells characterized by high number of fragmented and pulverized chromosomes, suggesting that the compound could cause a massive genomic rearrangement by inducing catastrophic events. The BPA-induced DNA damage was observed mainly in TCD4+ and TCD8+ subsets of T lymphocytes and was mediated by the increase of ERK1/2 phosphorylation, p21/Waf1 and PARP1 protein expression. Intriguingly, we observed for the first time that BPA-induced effects were associated to a sex specific modulation of ERα and ERβ in human PBMC. Immunofluorescence analysis of rat hippocampus corroborated in vitro findings showing that BPA induced ɣH2AX phosphorylation in microglia and astrocytosis by decreasing ERα expression within the dentate gyrus. Overall these results suggest that BPA can alter immune surveillance functions at both peripheral and central level with a potential risk for cancer, neuroinflammation and neurodegeneration., Competing Interests: Declaration of competing interest The Authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Among biological approaches to the removal of aromatic amines and phenols from wastewater, the so-called enzyme-catalyzed polymerization and precipitation (ECPP) process relies on the use of oxidoreductases acting via radical mechanisms and characterized by a rather relaxed substrate specificity, such as laccase, tyrosinase and peroxidases. The main technical constraints of ECPP processes are due to a variety of enzyme deactivation phenomena occurring during catalysis and to the incomplete removal of oxidation products from solution. In order to put ECPP into practice, these drawbacks have to be either counteracted or minimized. Although several approaches, such as enzyme immobilization and reaction engineering, have been proposed to limit these constraints, this review is intended to provide a wide survey on some chemical additives with either protective or coagulating effects that have been so far employed for these purposes.

Laccases catalyze the one-electron oxidation of a broad range of substrates coupled to the 4 electron reduction of O2 to H2O. Phenols are typical substrates, because their redox potentials (ranging from 0.5 to 1.0 V vs. NHE) are low enough to allow electron abstraction by the T1 Cu(II) that, although a relatively modest oxidant (in the 0.4-0.8 V range), is the electron-acceptor in laccases. The present study comparatively investigated the oxidation performances of Trametes villosa and Myceliophthora thermophila laccases, two enzymes markedly differing in redox potential (0.79 and 0.46 V). The oxidation efficiency and kinetic constants of laccase-catalyzed conversion of putative substrates were determined. Hammett plots related to the oxidation of substituted phenols by the two laccases, in combination with the kinetic isotope effect determination, confirmed a rate-determining electron transfer from the substrate to the enzyme. The efficiency of oxidation was found to increase with the decrease in redox potential of the substrates, and the Marcus reorganisation energy for electron transfer to the T1 copper site was determined. Steric hindrance to substrate docking was inferred because some of the phenols and anilines investigated, despite possessing a redox potential compatible with one-electron abstraction, were scarcely oxidised. A threshold value of steric hindrance of the substrate, allowed for fitting into the active site of T. villosa laccase, was extrapolated from structural information provided by X-ray analysis of T. versicolor lac3B, sharing an identity of 99% at the protein level, thus enabling us to assess the relative contribution of steric and redox properties of a substrate in determining its susceptibility to laccase oxidation. The inferred structural threshold is compatible with the distance between two phenylalanine residues that mark the entrance to the active site. Interaction of the substrate with other residues of the active site is commented on.

The phytotoxicity of olive-mill wastewater (OMW) has been suggested to be mainly due to its phenolic components. This study investigated the impact of three different low-cost dephenolization treatments on the wastewater phytotoxicity. To this aim, germinability of maize (Zea mays L.) seeds sown on a sandy-loamy soil which had been spread with different volumes (from 40 to 160m(3)ha(-1)) of either biologically-treated OMW or relative incubation control was determined. Biological treatments included either Panus tigrinus liquid cultures or incubation with commercial laccase (1UIml(-1)) or an innovative sequential combination of laccase and P. tigrinus cultures. All treatments markedly reduced phytotoxicity and promising results were obtained with commercial laccase. In fact, germinability and mean germination times in soil spread with laccase-treated OMW, did not significantly differ from those observed in soil irrigated with tap water (control) up to OMW volumes of 120m(3)ha(-1). Although the highest phenol reduction (ca. 81%) was obtained by the sequential use of laccase and P. tigrinus, the feasibility of the enzyme treatment is undoubtedly more convincing under the technological point of view.

This study was aimed at assessing the potential of the white-rot fungus Panus tigrinus CBS 577.79 in removing organic load, color and toxic phenols from agro-industrial effluent olive-mill wastewater (OMW). The influence of wastewater composition on P. tigrinus degradative capability was investigated in shaken cultures using two different OMWs. The initial soluble COD of 85,000 mg l(-1) led to a delay in removal of color, organic load and phenol by the fungus. This was associated with delayed onset of laccase and Mn-dependent peroxidase. On the other hand, P. tigrinus, when grown on OMW with an initial soluble COD content of 43,000 mg l(-1), promptly and efficiently removed the aforementioned components. Chromatographic analyses showed that 4-hydroxy-substituted simple phenols were predominantly removed. The polymeric aromatic fraction underwent simultaneous polymerization and depolymerization. This study is a contribution to the understanding of the degradative specificity of P. tigrinus on OMW aromatic components and provides good indications for possible future applications of the fungus.

Dry olive mill residue (DOR) is a solid waste arising from the olive oil two-phase extraction system. The objective of the present study was to investigate the impact of an aerobic treatment of DOR with selected lignin-degrading fungi on both organic matter evolution and residual phytotoxicity of the waste. To this aim, several white-rot fungi, including Phlebia radiata, Coriolopsis rigida, Phanerochaete chrysosporium, Pycnoporus cinnabarinus, Poria subvermispora and Pleurotus pulmonarius were inoculated under axenic conditions for 2 and 20 weeks. The chemical composition and phytotoxicity of DOR were scarcely affected by fungi after 2 weeks incubation. By contrast, both a significant depletion of phenolic compounds and a partial removal of phytoxicity towards Lycopersicum esculentum plants were generally obtained after 20 weeks. The most effective fungus in degrading lignin, total phenols and in removing phytotoxicity was C. rigida. A high correlation was observed between phytotoxicity and phenols added to soil with the waste. [Copyright &y& Elsevier]

Abstract: The use of stoned olive pomace (SOP) as an unconventional feedstuff for livestock is limited by its inherently low crude protein (CP) content and by the presence of anti-nutritional compounds such as phenols. Aim of this study was to assess whether solid-state fermentation of SOP with selective lignin-degrading fungi might ameliorate nutritional properties of the waste. Incubation of SOP, mixed (25%, w/w) with various conventional feedstuffs (i.e., wheat bran, wheat middlings, barley grains, crimson clover, wheat flour shorts and field beans), with Pleurotus ostreatus and Pleurotus pulmonarius led to significant CP increases, ranging from 7 to 29%, and marked removal (from ca. 50–90%) of phenols after 6 weeks. Both species, however, led to moderate delignification associated with significant consumption of hemicelluloses. Consequently, no improvements of both organic matter digestibility (OMD) and net energy of SOP–feedstuff mixtures occurred after the fungal colonization. [Copyright &y& Elsevier]

Abstract: Dry olive mill residue (DOR), the by-product of the two-phase extraction process, is very rich in organic matter and nutritionally relevant cations. For this reason, the agronomic use of this waste has been suggested although DOR exhibits significant phytotoxicity. The objective of this study was to investigate the impact of Paecilomyces farinosus on both organic matter modification and detoxification of this waste. Humification ratio in DOR colonized by the fungus for 20 weeks was increased by about 65% with respect to the abiotic control and humification index reached 0.38, a value that characterizes well-humified materials. High performance size-exclusion chromatography of humic acids from fungal cultures showed a marked increase in both weight-averaged and number-averaged molecular weights with respect to abiotic controls. Water-soluble phenols were reduced by 45% in 20-week-old P. farinosus cultures on DOR and mass-balance ultra-filtration showed that the relative abundance of the molecular weight fraction of phenols above 30kDa increased from 31 to 72% suggesting the occurrence of polymerization. Experiments performed with alfalfa grown on soils containing 2.5% (w/w) of abiotic controls and fungal-treated DOR showed that phytotoxicity was totally suppressed in the waste that underwent fungal treatment. [Copyright &y& Elsevier]