Assessing the activity of different plant-derived molecules and potential biological nitrification inhibitors on a range of soil ammonia- and nitrite-oxidizing strains.

IMPORTANCE: Synthetic nitrification inhibitors are routinely used with nitrogen fertilizers to reduce nitrogen losses from agroecosystems, despite having drawbacks like poor efficiency, cost, and entry into the food chain. Plant-derived BNIs constitute a more environmentally conducive alternative. Knowledge on the activity of BNIs to soil nitrifiers is largely based on bioassays with a single Nitrosomonas europaea strain which does not constitute a dominant member of the community of ammonia-oxidizing microorganisms (AOM) in soil. We determined the activity of several plant-derived molecules reported as having activity, including the recently discovered maize-isolated BNI, zeanone, and its natural analog, 2-methoxy-1,4-naphthoquinone, on a range of ecologically relevant AOM and one nitrite-oxidizing bacterial culture, expanding our knowledge on the intrinsic inhibition potential of BNIs toward AOM and highlighting the necessity for a deeper understanding of the effect of BNIs on the overall soil microbiome integrity before their further use in agricultural settings.

Land Spreading of Wastewaters from the Fruit-Packaging Industry and Potential Effects on Soil Microbes: Effects of the Antioxidant Ethoxyquin and Its Metabolites on Ammonia Oxidizers.

Thiabendazole (TBZ), imazalil (IMZ), ortho-phenylphenol (OPP), diphenylamine (DPA), and ethoxyquin (EQ) are used in fruit-packaging plants (FPP) with the stipulation that wastewaters produced by their application would be depurated on site. However, no such treatment systems are currently in place, leading FPP to dispose of their effluents in agricultural land. We investigated the dissipation of those pesticides and their impact on soil microbes known to have a key role on ecosystem functioning. OPP and DPA showed limited persistence (50% dissipation time [DT50], 0.6 and 1.3 days) compared to TBZ and IMZ (DT50, 47.0 and 150.8 days). EQ was rapidly transformed to the short-lived quinone imine (QI) (major metabolite) and the more persistent 2,4-dimethyl-6-ethoxyquinoline (EQNL) (minor metabolite). EQ and OPP exerted significant inhibition of potential nitrification, with the effect of the former being more persistent. This was not reflected in the abundance (determined by quantitative PCR [qPCR]) of the amoA gene of ammonia-oxidizing bacteria (AOB) and archaea (AOA). Considering the above discrepancy and the metabolic pattern of EQ, we further investigated the hypothesis that its metabolites and not only EQ were toxic to ammonia oxidizers. Potential nitrification, amoA gene abundance, and amoA gene transcripts of AOB and AOA showed that QI was probably responsible for the inhibition of nitrification. Our findings have serious ecological and practical implications for soil productivity and N conservation in agriculturally impacted ecosystems and stress the need to include metabolites and RNA-based methods when the soil microbial toxicity of pesticides is assessed.

The potential of organic substrates based on mushroom substrate and straw to dissipate fungicides contained in effluents from the fruit-packaging industry - Is there a role for Pleurotus ostreatus?

Citrus fruit-packaging plants (FPP) produce large wastewater volumes with high loads of fungicides like ortho-phenylphenol (OPP) and imazalil (IMZ). No methods are in place for the treatment of those effluents and biobeds appear as a viable alternative. We employed a column study to investigate the potential of spent mushroom substrate (SMS) of Pleurotus ostreatus, either alone or in mixture with straw and soil plus a mixture of straw /soil to retain and dissipate IMZ and OPP. The role of P. ostreatus on fungicides dissipation was also investigated by studying in parallel the performance of fresh mushroom substrate of P. ostreatus (FMS) and measuring lignolytic enzymatic activity in the leachates. All substrates effectively reduced the leaching of OPP and IMZ which corresponded to 0.014-1.1% and 0.120-0.420% of their initial amounts respectively. Mass balance analysis revealed that FMS and SMS/Straw/Soil (50/25/25 by vol) offered the most efficient removal of OPP and IMZ from wastewaters respectively. Regardless of the substrate, OPP was restricted in the top 0-20cm of the columns and was bioavailable (extractable with water), compared to IMZ which was less bioavailable (extractable with acetonitrile) but diffused at deeper layers (20-50, 50-80cm) in the SMS- and Straw/Soil-columns. PLFAs showed that fungal abundance was significantly lower in the top layer of all substrates from where the highest pesticide amounts were recovered suggesting an inhibitory effect of fungicides on total fungi in the substrates tested. Our data suggest that biobeds packed with SMS-rich substrates could ensure the efficient removal of IMZ and OPP from wastewaters of citrus FPP.

New functions of DDR1 collagen receptor in tumor dormancy, immune exclusion and therapeutic resistance.

The tumor microenvironment facilitates cancer progression and therapeutic resistance. Tumor collagens and their architecture play an essential role in this process. However, little is known about the mechanisms by which tumor cells sense and respond to this extracellular matrix environment. Recently, the Discoidin Domain Receptor 1 (DDR1), a collagen receptor and tyrosine kinase has emerged as an important player in this malignant process, although the underlying signaling mechanisms remain unclear. Here, we review new DDR1 functions in tumor dormancy following dissemination, immune exclusion and therapeutic resistance induced by stromal collagens deposition. We also discuss the signaling mechanisms behind these tumor activities and the therapeutic strategies aiming at targeting these collagens-dependent tumor responses.

The Effects of Quinone Imine, a New Potent Nitrification Inhibitor, Dicyandiamide, and Nitrapyrin on Target and Off-Target Soil Microbiota.

Dicyandiamide (DCD) and nitrapyrin (NP) are nitrification inhibitors (NIs) used in agriculture for over 40 years. Recently, ethoxyquin (EQ) was proposed as a novel potential NI, acting through its derivative quinone imine (QI). Still, the specific activity of these NIs on the different groups of ammonia-oxidizing microorganisms (AOM), and mostly their effects on other soil microbiota remain unknown. We determined the impact of QI, and comparatively of DCD and NP, applied at two doses (regular versus high), on the function, diversity, and dynamics of target (AOM), functionally associated (nitrite-oxidizing bacteria-NOB), and off-target prokaryotic and fungal communities in two soils mainly differing in pH (5.4 versus 7.9). QI was equally effective to DCD but more effective than NP in inhibiting nitrification in the acidic soil, while in the alkaline soil QI was less efficient than DCD and NP. This was attributed to the higher activity of QI toward AOA prevailing in the acidic soil. All NIs induced significant effects on the composition of the AOB community in both soils, unlike AOA, which were less responsive. Beyond on-target effects, we noted an inhibitory effect of all NIs on the abundance of NOB in the alkaline soil, with Nitrobacter being more sensitive than Nitrospira. QI, unlike the other NIs, induced significant changes in the composition of the bacterial and fungal communities in both soils. Our findings have serious implications for the efficiency and future use of NIs on agriculture and provide unprecedented evidence for the potential off-target effects of NIs on soil microbiota. IMPORTANCE NIs could improve N use efficiency and decelerate N cycling. Still, we know little about their activity on the distinct AOM groups and about their effects on off-target soil microorganisms. Here, we studied the behavior of a new potent NI, QI, compared to established NIs. We show that (i) the variable efficacy of NIs across soils with different pH reflects differences in the inherent specific activity of the NIs to AOA and AOB; (ii) beyond AOM, NIs exhibit negative effects on other nitrifiers, like NOB; (iii) QI was the sole NI that significantly affected prokaryotic and fungal diversity. Our findings (i) highlight the need for novel NI strategies that consider the variable sensitivity of AOM groups to the different NIs (ii) identify QI as a potent AOA inhibitor, and (iii) stress the need for monitoring NIs' impact on off-target soil microorganisms to ensure sustainable N fertilizers use and soil ecosystem functioning.

Myocardial inflammation in Duchenne Muscular Dystrophy as a precipitating factor for heart failure: a prospective study.

BACKGROUND: In patients with Duchenne Muscular Dystrophy (DMD), the absent or diminished dystrophin leads to progressive skeletal muscle and heart failure. We evaluated the role of myocardial inflammation as a precipitating factor in the development of heart failure in DMD. METHODS: 20 DMD patients (aged 15-18 yrs) and 20 age-matched healthy volunteers were studied and followed-up for 2 years. Evaluation of myocarditis with cardiovascular magnetic resonance imaging (CMR) was performed using STIR T2-weighted (T2W), T1-weighted (T1W) before and after contrast media and late enhanced images (LGE). Left ventricular volumes and ejection fraction were also calculated. Myocardial biopsy was performed in patients with positive CMR and immunohistologic and polymerase chain reaction (PCR) analysis was employed. RESULTS: In DMD patients, left ventricular end-diastolic volume (LVEDV) was not different compared to controls. Left ventricular end-systolic volume (LVESV) was higher (45.1 +/- 6.6 vs. 37.3 +/- 3.8 ml, p < 0.001) and left ventricular ejection fraction (LVEF) was lower (53.9 +/- 2.1 vs. 63 +/- 2.4%, p < 0.001). T2 heart/skeletal muscle ratio and early T1 ratio values in DMD patients presented no difference compared to controls. LGE areas were identified in six DMD patients. In four of them with CMR evidence of myocarditis, myocardial biopsy was performed. Active myocarditis was identified in one and healing myocarditis in three using immunohistology. All six patients with CMR evidence of myocarditis had a rapid deterioration of left ventricular function during the next year. CONCLUSIONS: DMD patients with myocardial inflammation documented by CMR had a rigorous progression to heart failure.

Comparison of Novel and Established Nitrification Inhibitors Relevant to Agriculture on Soil Ammonia- and Nitrite-Oxidizing Isolates.

Nitrification inhibitors (NIs) applied to soil reduce nitrogen fertilizer losses from agro-ecosystems. NIs that are currently registered for use in agriculture appear to selectively inhibit ammonia-oxidizing bacteria (AOB), while their impact on other nitrifiers is limited or unknown. Ethoxyquin (EQ), a fruit preservative shown to inhibit ammonia-oxidizers (AO) in soil, is rapidly transformed to 2,6-dihydro-2,2,4-trimethyl-6-quinone imine (QI), and 2,4-dimethyl-6-ethoxy-quinoline (EQNL). We compared the inhibitory potential of EQ and its derivatives with that of dicyandiamide (DCD), nitrapyrin (NP), and 3,4-dimethylpyrazole-phosphate (DMPP), NIs that have been used in agricultural settings. The effect of each compound on the growth of AOB (Nitrosomonas europaea, Nitrosospira multiformis), ammonia-oxidizing archaea (AOA; "Candidatus Nitrosocosmicus franklandus," "Candidatus Nitrosotalea sinensis"), and a nitrite-oxidizing bacterium (NOB; Nitrobacter sp. NHB1), all being soil isolates, were determined in liquid culture over a range of concentrations by measuring nitrite production or consumption and qPCR of amoA and nxrB genes, respectively. The degradation of NIs in the liquid cultures was also determined. In all cultures, EQ was transformed to the short-lived QI (major derivative) and the persistent EQNL (minor derivative). They all showed significantly higher inhibition activity of AOA compared to AOB and NOB isolates. QI was the most potent AOA inhibitor (EC50 = 0.3-0.7 µM) compared to EQ (EC50 = 1-1.4 µM) and EQNL (EC50 = 26.6-129.5 µM). The formation and concentration of QI in EQ-amended cultures correlated with the inhibition patterns for all isolates suggesting that it was primarily responsible for inhibition after application of EQ. DCD and DMPP showed greater inhibition of AOB compared to AOA or NOB, with DMPP being more potent (EC50 = 221.9-248.7 µM vs EC50 = 0.6-2.1 µM). NP was the only NI to which both AOA and AOB were equally sensitive with EC50s of 0.8-2.1 and 1.0-6.7 µM, respectively. Overall, EQ, QI, and NP were the most potent NIs against AOA, NP, and DMPP were the most effective against AOB, while NP, EQ and its derivatives showed the highest activity against the NOB isolate. Our findings benchmark the activity range of known and novel NIs with practical implications for their use in agriculture and the development of NIs with broad or complementary activity against all AO.

Genome-Based Metabolic Reconstruction Unravels the Key Role of B12 in Methionine Auxotrophy of an Ortho-Phenylphenol-Degrading Sphingomonas haloaromaticamans.

Auxotrophy to amino acids and vitamins is a common feature in the bacterial world shaping microbial communities through cross-feeding relations. The amino acid auxotrophy of pollutant-degrading bacteria could hamper their bioremediation potential, however, the underlying mechanisms of auxotrophy remain unexplored. We employed genome sequence-based metabolic reconstruction to identify potential mechanisms driving the amino acid auxotrophy of a Sphingomonas haloaromaticamans strain degrading the fungicide ortho-phenylphenol (OPP) and provided further verification for the identified mechanisms via in vitro bacterial assays. The analysis identified potential gaps in the biosynthesis of isoleucine, phenylalanine and tyrosine, while methionine biosynthesis was potentially effective, relying though in the presence of B12. Supplementation of the bacterium with the four amino acids in all possible combinations rescued its degrading capacity only with methionine. Genome sequence-based metabolic reconstruction and analysis suggested that the bacterium was incapable of de novo biosynthesis of B12 (missing genes for the construction of the corrin ring) but carried a complete salvage pathway for corrinoids uptake from the environment, transmembrane transportation and biosynthesis of B12. In line with this the bacterium maintained its degrading capacity and growth when supplied with environmentally relevant B12 concentrations (i.e., 0.1 ng ml-1). Using genome-based metabolic reconstruction and in vitro testing we unraveled the mechanism driving the auxotrophy of a pesticide-degrading S. haloaromaticamans. Further studies will investigate the corrinoids preferences of S. haloaromaticamans for optimum growth and OPP degradation.

Cranio-maxillofacial injuries in Homer's Iliad.

INTRODUCTION: Homer's Iliad, being one of the oldest and greatest European epic poems, is divided into 24 "books" or "rhapsodies", in which war injuries in general, and in particular cranio-maxillofacial (CMF) injuries, are described in a unique and detailed manner. MATERIAL AND METHOD: Homer's Iliad, Loeb Classical Library, translated by A.T. Murray, and revised by W.F. Wyatt, Harvard University Press, 2nd ed., Cambridge, Massachusetts, 1999, as well as the modern Greek translation by I. Polylas of Homer's Iliad, Publishing Organization for Educational Material, 4th ed., Athens, 1975, was studied for descriptions of CMF injuries, aiming at the presentation of their total number, received area of the head and neck, outcome, cause of injuries, and the engaged warriors. RESULTS: Forty-eight references regarding CMF injuries are found in the 24 books of Homer's Iliad. Forty-four of the CMF injuries were fatal, among them five were decapitations. The causes of the CMF injuries were usually strokes with weapons, while other means such as rocks and stones were also used. In the aforementioned injuries the engaged striking warriors were 17 Greeks and four Trojans, while the fallen warriors were eight Greeks and 38 Trojans. CONCLUSIONS: One could get an idea about the practice of Medicine and particularly of Surgery, in the 10th century BC in Ancient Greece, through the epic poems of Homer. The unique description of CMF injuries leads us to the conclusion that the anatomy of the head and neck was quite well known in those very old times, since the heroes and warriors of the Iliad knew exactly where to strike to achieve a fatal outcome.

Bioaugmentation of thiabendazole-contaminated soils from a wastewater disposal site: Factors driving the efficacy of this strategy and the diversity of the indigenous soil bacterial community.

The application of the fungicide thiabendazole (TBZ) in fruit packaging plants (FPP) results in the production of effluents which are often disposed in adjacent field sites. These require remediation to prevent further environmental dispersal of TBZ. We assessed the bioaugmentation potential of a newly isolated TBZ-degrading bacterial consortium in a naturally contaminated soil (NCS) exhibiting a natural gradient of TBZ levels (12000, 400, 250 and 12 mg kg-1). The effect of aging on bioaugmentation efficacy was comparatively tested in a soil with similar physicochemical properties and soil microbiota, which was artificially, contaminated with the same TBZ levels (ACS). The impact of bioaugmentation and TBZ on the bacterial diversity in the NCS was explored via amplicon sequencing. Bioaugmentation effectively removed TBZ from both soils at levels up to 400 mg kg-1 but failed at the highest contamination level (12000 mg kg-1). Dissipation of TBZ in bioaugmented samples showed a concentration-dependent pattern, while aging of TBZ had a slight effect on bioaugmentation efficiency. Bioaugmentation had no impact on the soil bacterial diversity, in contrast to TBZ contamination. Soils from the hotspots of TBZ contamination (12000 mg kg-1) showed a drastically lower α-diversity driven by the dominance of ß- and γ-proteobacteria at the expense of all other bacterial phyla, especially Actinobacteria. Overall, bioaugmentation with specialized microbial inocula could be an effective solution for the recovery of disposal sites contaminated with persistent chemicals like TBZ.

Metabolic and Evolutionary Insights in the Transformation of Diphenylamine by a Pseudomonas putida Strain Unravelled by Genomic, Proteomic, and Transcription Analysis.

Diphenylamine (DPA) is a common soil and water contaminant. A Pseudomonas putida strain, recently isolated from a wastewater disposal site, was efficient in degrading DPA. Thorough knowledge of the metabolic capacity, genetic stability and physiology of bacteria during biodegradation of pollutants is essential for their future industrial exploitation. We employed genomic, proteomic, transcription analyses and plasmid curing to (i) identify the genetic network of P. putida driving the microbial transformation of DPA and explore its evolution and origin and (ii) investigate the physiological response of bacterial cells during degradation of DPA. Genomic analysis identified (i) two operons encoding a biphenyl (bph) and an aniline (tdn) dioxygenase, both flanked by transposases and (ii) two operons and several scattered genes encoding the ortho-cleavage of catechol. Proteomics identified 11 putative catabolic proteins, all but BphA1 up-regulated in DPA- and aniline-growing cells, and showed that the bacterium mobilized cellular mechanisms to cope with oxidative stress, probably induced by DPA and its derivatives. Transcription analysis verified the role of the selected genes/operons in the metabolic pathway: DPA was initially transformed to aniline and catechol by a biphenyl dioxygenase (DPA-dioxygenase); aniline was then transformed to catechol which was further metabolized via the ortho-cleavage pathway. Plasmid curing of P. putida resulted in loss of the DPA and aniline dioxygenase genes and the corresponding degradation capacities. Overall our findings provide novel insights into the evolution of the DPA degradation pathway and suggests that the degradation capacity of P. putida was acquired through recruitment of the bph and tdn operons via horizontal gene transfer.

Author Correction: Metabolic pathway and cell adaptation mechanisms revealed through genomic, proteomic and transcription analysis of a Sphingomonas haloaromaticamans strain degrading ortho-phenylphenol.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Lab to Field Assessment of the Ecotoxicological Impact of Chlorpyrifos, Isoproturon, or Tebuconazole on the Diversity and Composition of the Soil Bacterial Community.

Pesticides are intentionally applied to agricultural fields for crop protection. They can harm non-target organisms such as soil microorganisms involved in important ecosystem functions with impacts at the global scale. Within the frame of the pesticide registration process, the ecotoxicological impact of pesticides on soil microorganisms is still based on carbon and nitrogen mineralization tests, despite the availability of more extensive approaches analyzing the abundance, activity or diversity of soil microorganisms. In this study, we used a high-density DNA microarray (PhyloChip) and 16S rDNA amplicon next-generation sequencing (NGS) to analyze the impact of the organophosphate insecticide chlorpyrifos (CHL), the phenyl-urea herbicide isoproturon (IPU), or the triazole fungicide tebuconazole (TCZ) on the diversity and composition of the soil bacterial community. To our knowledge, it is the first time that the combination of these approaches are applied to assess the impact of these three pesticides in a lab-to-field experimental design. The PhyloChip analysis revealed that although no significant changes in the composition of the bacterial community were observed in soil microcosms exposed to the pesticides, significant differences in detected operational taxonomic units (OTUs) were observed in the field experiment between pesticide treatments and control for all three tested pesticides after 70 days of exposure. NGS revealed that the bacterial diversity and composition varied over time. This trend was more marked in the microcosm than in the field study. Only slight but significant transient effects of CHL or TCZ were observed in the microcosm and the field study, respectively. IPU was not found to significantly modify the soil bacterial diversity or composition. Our results are in accordance with conclusions of the Environmental Food Safety Authority (EFSA), which concluded that these three pesticides may have a low risk toward soil microorganisms.

A 6-month follow-up of intermittent levosimendan administration effect on systolic function, specific activity questionnaire, and arrhythmia in advanced heart failure.

BACKGROUND: Levosimendan (LS) improves cardiac contractility without increasing myocardial oxygen demand. We administrated LS on a monthly intermittent 24-hour protocol and evaluated the clinical effect after 6 months in a randomized, open, prospective study. METHODS AND RESULTS: Fifty patients (age 45-65 years) with LV systolic dysfunction and New York Heart Association (NYHA) III or IV were randomized in 2 groups. LS group (n = 25) was compared with a control group (n = 25) matched for sex, age, and NYHA class. LS was given monthly on a 24-hour intravenous protocol for 6 months. Patients were evaluated by specific activity questionnaire (SAQ) and echocardiography (ECHO) before and 3 to 5 days after last drug administration, whereas 24-hour Holter recording was performed before and during last drug administration. Patients in LS and control group had same baseline SAQ, ECHO, and Holter parameters. At the end of the study, a larger proportion of patients in the levosimendan group reported improvement in symptoms (dyspnea and fatigue) (65% versus 20% in controls, P < .01). After 6 months, the LS group had a significant increase in LV ejection fraction versus controls (28 +/- 7 versus 21 +/- 4 %, P = .003), LV shortening fraction (15 +/- 3 versus 11 +/- 3 %, P = .006) and a decrease in mitral regurgitation (1.5 +/- 0.8 versus 2.7 +/- 0.6, P = .0001). There was no increase in supraventricular or ventricular beats or supraventricular tachycardia and VT episodes in LS group, compared with controls. Two patients from the LS group died in the 6-month follow-up period, compared with 8 patients in the control group (8% versus 32%, P < .05). CONCLUSIONS: A 6-month intermittent LS treatment in patients with decompensated advanced heart failure improved symptoms and LV systolic function.

Metabolic pathway and cell adaptation mechanisms revealed through genomic, proteomic and transcription analysis of a Sphingomonas haloaromaticamans strain degrading ortho-phenylphenol.

Ortho-phenylphenol (OPP) is a fungicide contained in agro-industrial effluents produced by fruit-packaging plants. Within the frame of developing bio-strategies to detoxify these effluents, an OPP-degrading Sphingomonas haloaromaticamans strain was isolated. Proteins/genes with a putative catabolic role and bacterium adaptation mechanisms during OPP degradation were identified via genomic and proteomic analysis. Transcription analysis of all putative catabolic genes established their role in the metabolism of OPP. The formation of key transformation products was verified by chromatographic analysis. Genomic analysis identified two orthologous operons encoding the ortho-cleavage of benzoic acid (BA) (ben/cat). The second ben/cat operon was located in a 92-kb scaffold along with (i) an operon (opp) comprising genes for the transformation of OPP to BA and 2-hydroxypenta-2,4-dienoate (and genes for its transformation) and (ii) an incomplete biphenyl catabolic operon (bph). Proteomics identified 13 up-regulated catabolic proteins when S. haloaromaticamans was growing on OPP and/or BA. Transcription analysis verified the key role of the catabolic operons located in the 92-kb scaffold, and flanked by transposases, on the transformation of OPP by S. haloaromaticamans. A flavin-dependent monoxygenase (OppA1), one of the most up-regulated proteins in the OPP-growing cells, was isolated via heterologous expression and its catabolic activity was verified in vitro.

Novel insights into the metabolic pathway of iprodione by soil bacteria.

Microbial degradation constitutes the key soil dissipation process for iprodione. We recently isolated a consortium, composed of an Arthrobacter sp. strain C1 and an Achromobacter sp. strain C2, that was able to convert iprodione to 3,5-dichloroaniline (3,5-DCA). However, the formation of metabolic intermediates and the role of the strains on iprodione metabolism remain unknown. We examined the degradation of iprodione and its suspected metabolic intermediates, 3,5-dichlorophenyl-carboxamide (metabolite I) and 3,5-dichlorophenylurea-acetate (metabolite II), by strains C1 and C2 and their combination under selective (MSM) and nutrient-rich conditions (LB). Bacterial growth during degradation of the tested compounds was determined by qPCR. Strain C1 rapidly degraded iprodione (DT50 = 2.3 h) and metabolite II (DT50 = 2.9 h) in MSM suggesting utilization of isopropylamine, transiently formed by hydrolysis of iprodione, and glycine liberated during hydrolysis of metabolite II, as C and N sources. In contrast, strain C1 degraded metabolite I only in LB and growth kinetics suggested the involvement of a detoxification process. Strain C2 was able to transform iprodione and its metabolites only in LB. Strain C1 degraded vinclozolin, a structural analog of iprodione, and partially propanil, but not procymidone and phenylureas indicating a structure-dependent specificity related to the substituents of the carboxamide moiety.

Effects of the inducible nitric oxide synthase inhibitor aminoguanidine in two different rat models of schizophrenia.

Several lines evidence indicate that the non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist ketamine and the mixed dopamine (DA) D1/D2 receptor agonist apomorphine induce schizophrenia-like symptoms in rodents, including memory impairments and social withdrawal. Nitric oxide (NO) has been proposed to act as an intracellular messenger in the brain and its overproduction is associated with schizophrenia. The current study was designed to investigate the ability of the inducible NO synthase (iNOS) inhibitor aminoguanidine (AG) to counteract schizophrenia-like behavioural deficits produced by ketamine and apomorphine in rats. The efficacy of AG to antagonize extinction of recognition memory, ketamine and apomorphine-induced recognition memory impairments was tested utilizing the novel object recognition task (NORT). Further, the efficacy of AG to attenuate ketamine-induced social withdrawal was examined in the social interaction test. AG (25 and 50mg/kg) antagonized extinction of recognition memory and reversed ketamine (3mg/kg) and apomorphine (1mg/kg)-induced recognition memory deficits. In contrast, AG (50 and 100mg/kg) did not counteract the ketamine (8mg/kg)-induced social isolation. The present data show that the iNOS inhibitor AG counteracted extinction of recognition memory and reversed recognition memory deficits produced by dysfunction of the glutamatergic and the dopaminergic (DAergic) system in rats. Therefore, AG may be efficacious in attenuating memory impairments often observed in schizophrenia patients.

The dissipation of fipronil, chlorpyrifos, fosthiazate and ethoprophos in soils from potato monoculture areas: first evidence for the enhanced biodegradation of fosthiazate.

BACKGROUND: A limited number of pesticides are available for the control of soil pests in potato. This, together with the monoculture nature of potato cultivation, does not favour chemical rotation, increasing the risk of reduced biological efficacy due to microbial adaptation. The dissipation of three major organophosphates (chlorpyrifos, ethoprophos and fosthiazate) was studied in comparison with fipronil, an insecticide recently introduced in potato cultivation, in 17 soils from potato monoculture areas in Greece to explore the extent of enhanced biodegradation development. RESULTS: The dissipation time of the four pesticides varied in the different soils, with DT50 values of 1.7-30.8 days, 2.7-56 days, 7.0-31.0 days and 24.5-116.5 days for fosthiazate, chlorpyrifos, ethoprophos and fipronil, respectively. A rapid dissipation of ethoprophos and fosthiazate in two soils with previous exposure to these nematicides provided first evidence for the development of enhanced biodegradation. Sterilisation of the given soils inhibited the dissipation of fosthiazate. Additionally, fosthiazate dissipation in the soils increased upon repeated applications. CONCLUSION: The development of enhanced biodegradation of fosthiazate in soils from potato monoculture regions was verified. This is the first report of enhanced biodegradation for this chemical. Further studies will focus on the isolation of microorganisms responsible for the dissipation of fosthiazate.

Dissipation and adsorption of isoproturon, tebuconazole, chlorpyrifos and their main transformation products under laboratory and field conditions.

Assessment of dissipation constitutes an integral part of pesticides risk assessment since it provides an estimate of the level and the duration of exposure of the terrestrial ecosystem to pesticides. Within the frame of an overall assessment of the soil microbial toxicity of pesticides, we investigated the dissipation of a range of dose rates of three model pesticides, isoproturon (IPU), tebuconazole (TCZ), and chlorpyrifos (CHL), and the formation and dissipation of their main transformation products following a tiered lab-to-field approach. The adsorption of pesticides and their transformation products was also determined. IPU was the least persistent pesticide showing a dose-dependent increase in its persistence in both laboratory and field studies. CHL dissipation showed a dose-dependent increase under laboratory conditions and an exact opposite trend in the field. TCZ was the most persistent pesticide under lab conditions showing a dose-dependent decrease in its dissipation, whereas in the field TCZ exhibited a biphasic dissipation pattern with extrapolated DT90s ranging from 198 to 603.4days in the ×1 and ×2 dose rates, respectively. IPU was demethylated to mono- (MD-IPU) and di-desmethyl-isoproturon (DD-IPU) which dissipated following a similar pattern with the parent compound. CHL was hydrolyzed to 3,5,6-trichloro-2-pyridinol (TCP) which dissipated showing a reverse dose-dependent pattern compared to CHL. Pesticides adsorption affinity increased in the order IPU

Integrated biodepuration of pesticide-contaminated wastewaters from the fruit-packaging industry using biobeds: Bioaugmentation, risk assessment and optimized management.

Wastewaters from fruit-packaging plants contain high loads of toxic and persistent pesticides and should be treated on site. We evaluated the depuration performance of five pilot biobeds against those effluents. In addition we tested bioaugmentation with bacterial inocula as a strategy for optimization of their depuration capacity. Finally we determined the composition and functional dynamics of the microbial community via q-PCR. Practical issues were also addressed including the risk associated with the direct environmental disposal of biobed-treated effluents and decontamination methods for the spent packing material. Biobeds showed high depuration capacity (>99.5%) against all pesticides with bioaugmentation maximizing their depuration performance against the persistent fungicide thiabendazole (TBZ). This was followed by a significant increase in the abundance of bacteria, fungi and of catabolic genes of aromatic compounds catA and pcaH. Bioaugmentation was the most potent decontamination method for spent packing material with composting being an effective alternative. Risk assessment based on practical scenarios (pome and citrus fruit-packaging plants) and the depuration performance of the pilot biobeds showed that discharge of the treated effluents into an 0.1-ha disposal site did not entail an environmental risk, except for TBZ-containing effluents where a larger disposal area (0.2ha) or bioaugmentation alleviated the risk.