scholarly journals Functional Redundancy of Linuron Degradation in Microbial Communities in Agricultural Soil and Biopurification Systems

2016 ◽  
Vol 82 (9) ◽  
pp. 2843-2853 ◽  
Author(s):  
Benjamin Horemans ◽  
Karolien Bers ◽  
Erick Ruiz Romero ◽  
Eva Pose Juan ◽  
Vincent Dunon ◽  
...  
Keyword(s):  
Agricultural Soil ◽  
Bacterial Consortium ◽  
Bacterial Degradation ◽  
Catabolic Gene ◽  
Bacterial Populations ◽  
Content Type ◽  
Respective Contribution ◽  
On Farm ◽  
Biopurification Systems

ABSTRACTThe abundance oflibA, encoding a hydrolase that initiates linuron degradation in the linuron-metabolizingVariovoraxsp. strain SRS16, was previously found to correlate well with linuron mineralization, but not in all tested environments. Recently, an alternative linuron hydrolase, HylA, was identified inVariovoraxsp. strain WDL1, a strain that initiates linuron degradation in a linuron-mineralizing commensal bacterial consortium. The discovery of alternative linuron hydrolases poses questions about the respective contribution and competitive character ofhylA- andlibA-carrying bacteria as well as the role of linuron-mineralizing consortia versus single strains in linuron-exposed settings. Therefore, dynamics ofhylAas well asdcaQas a marker for downstream catabolic functions involved in linuron mineralization, in response to linuron treatment in agricultural soil and on-farm biopurification systems (BPS), were compared with previously reportedlibAdynamics. The results suggest that (i) organisms containing eitherlibAorhylAcontribute simultaneously to linuron biodegradation in the same environment, albeit to various extents, (ii) environmental linuron mineralization depends on multispecies bacterial food webs, and (iii) initiation of linuron mineralization can be governed by currently unidentified enzymes.IMPORTANCEA limited set of different isofunctional catabolic gene functions is known for the bacterial degradation of the phenylurea herbicide linuron, but the role of this redundancy in linuron degradation in environmental settings is not known. In this study, the simultaneous involvement of bacteria carrying one of two isofunctional linuron hydrolysis genes in the degradation of linuron was shown in agricultural soil and on-farm biopurification systems, as was the involvement of other bacterial populations that mineralize the downstream metabolites of linuron hydrolysis. This study illustrates the importance of the synergistic metabolism of pesticides in environmental settings.

scholarly journals Dynamics of the Linuron HydrolaselibAGene Pool Size in Response to Linuron Application and Environmental Perturbations in Agricultural Soil and On-Farm Biopurification Systems

2012 ◽  
Vol 78 (8) ◽  
pp. 2783-2789 ◽  
Author(s):  
Karolien Bers ◽  
Kristel Sniegowski ◽  
René De Mot ◽  
Dirk Springael
Keyword(s):  
Agricultural Soil ◽  
Environmental Changes ◽  
Gene Encoding ◽  
Soil Microcosms ◽  
Content Type ◽  
Environmental Perturbations ◽  
Biopurification System ◽  
Reported Data ◽  
On Farm ◽  
Biopurification Systems

ABSTRACTlibA, a gene encoding a novel type of linuron hydrolase, was recently identified in the linuron-mineralizingVariovoraxsp. strain SRS16. In order to assess the contribution oflibAto linuron degradation in environmental settings,libAabundance was monitored in response to the application of linuron and to environmental perturbations in agricultural soil microcosms and microcosms simulating the matrix of on-farm biopurification systems.libAnumbers were measured by real-time PCR and linked to reported data ofVariovoraxcommunity composition and linuron mineralization capacity. In the soil microcosms and one biopurification system setup,libAnumbers responded to the application of linuron and environmental changes in congruency with the modulation of linuron mineralization capacity and the occurrence of a particularVariovoraxphylotype (phylotype A). However, in another biopurification system setup, no such correlations were found. Our data suggest that in the simulated environmental settings, the occurrence oflibAcan be linked to the linuron mineralization capacity and thatlibAis primarily hosted byVariovoraxphylotype A strains. However, the results also suggest that, apart fromlibA, other, as-yet-unknown isofunctional genes play an important role in linuron mineralization in the environment.

scholarly journals Biodegradation of the Allelopathic Chemical Pterostilbene by a Sphingobium sp. Strain from the Peanut Rhizosphere

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Ri-Qing Yu ◽  
Zohre Kurt ◽  
Fei He ◽  
Jim C. Spain
Keyword(s):  
Pathogenic Fungi ◽  
Bacterial Degradation ◽  
Ecological Role ◽  
Microbial Infection ◽  
Catabolic Pathway ◽  
Content Type ◽  
Dead End ◽  
Initial Cleavage ◽  
Bacterial Interference

ABSTRACT Many plants produce allelopathic chemicals, such as stilbenes, to inhibit pathogenic fungi. The degradation of allelopathic compounds by bacteria associated with the plants would limit their effectiveness, but little is known about the extent of biodegradation or the bacteria involved. Screening of tissues and rhizosphere of peanut (Arachis hypogaea) plants revealed substantial enrichment of bacteria able to grow on resveratrol and pterostilbene, the most common stilbenes produced by the plants. Investigation of the catabolic pathway in Sphingobium sp. strain JS1018, isolated from the rhizosphere, indicated that the initial cleavage of pterostilbene was catalyzed by a carotenoid cleavage oxygenase (CCO), which led to the transient accumulation of 4-hydroxybenzaldehyde and 3,5-dimethoxybenzaldehyde. 4-Hydroxybenzaldehyde was subsequently used for the growth of the isolate, while 3,5-dimethoxybenzaldehyde was further converted to a dead-end metabolite with a molecular weight of 414 (C24H31O6). The gene that encodes the initial oxygenase was identified in the genome of strain JS1018, and its function was confirmed by heterologous expression in Escherichia coli. This study reveals the biodegradation pathway of pterostilbene by plant-associated bacteria. The prevalence of such bacteria in the rhizosphere and plant tissues suggests a potential role of bacterial interference in plant allelopathy. IMPORTANCE Pterostilbene, an analog of resveratrol, is a stilbene allelochemical produced by plants to inhibit microbial infection. As a potent antioxidant, pterostilbene acts more effectively than resveratrol as an antifungal agent. Bacterial degradation of this plant natural product would affect the allelopathic efficacy and fate of pterostilbene and thus its ecological role. This study explores the isolation and abundance of bacteria that degrade resveratrol and pterostilbene in peanut tissues and rhizosphere, the catabolic pathway for pterostilbene, and the molecular basis for the initial cleavage of pterostilbene. If plant allelopathy is an important process in agriculture and management of invasive plants, the ecological role of bacteria that degrade the allelopathic chemicals must be equally important.

scholarly journals Robust Linuron Degradation in On-Farm Biopurification Systems Exposed to Sequential Environmental Changes

2011 ◽  
Vol 77 (18) ◽  
pp. 6614-6621 ◽  
Author(s):  
Kristel Sniegowski ◽  
Karolien Bers ◽  
Jaak Ryckeboer ◽  
Peter Jaeken ◽  
Pieter Spanoghe ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Environmental Changes ◽  
Drought Period ◽  
Content Type ◽  
Pesticide Mixture ◽  
Operation Conditions ◽  
Severe Effect ◽  
Favorable Conditions ◽  
On Farm ◽  
Biopurification Systems

ABSTRACTOn-farm biopurification systems (BPS) treat pesticide-contaminated wastewater of farms through biodegradation. Adding pesticide-primed soil has been shown to be beneficial for the establishment of pesticide-degrading populations in BPS. However, no data exist on the response of pesticide-degrading microbiota, either endogenous or introduced with pesticide-primed soil, when BPS are exposed to expected less favorable environmental conditions like cold periods, drought periods, and periods without a pesticide supply. Therefore, the response of microbiota mineralizing the herbicide linuron in BPS microcosm setups inoculated either with a linuron-primed soil or a nonprimed soil to a sequence of such less favorable conditions was examined. A period without linuron supply or a drought period reduced the size of the linuron-mineralizing community in both setups. The most severe effect was recorded for the setup containing nonprimed soil, in which stopping the linuron supply decreased the linuron degradation capacity to nondetectable levels. In both systems, linuron mineralization rapidly reestablished after conventional operation conditions were restored. A cold period and feeding with a pesticide mixture did not affect linuron mineralization. The changes in the linuron-mineralizing capacity in microcosms containing primed soil were associated with the dynamics of a particularVariovoraxphylotype that previously had been associated with linuron mineralization. This study suggests that the pesticide-mineralizing community in BPS is robust in stress situations imposed by changes in environmental conditions expected to occur on farms. Moreover, it suggests that, in cases where effects do occur, recovery is rapid after restoring conventional operation conditions.

scholarly journals Improving accountability for farm animal welfare: the performative role of a benchmark device

2019 ◽  
Vol 33 (1) ◽  
pp. 32-58
Author(s):  
Josie McLaren ◽  
Tony Appleyard
Keyword(s):  
Animal Welfare ◽  
Farm Animal ◽  
Farm Animal Welfare ◽  
Content Type ◽  
Repetitive Process ◽  
The Social ◽  
Research Questions ◽  
On Farm

Purpose The purpose of this paper is to investigate accountability for farm animal welfare (FAW) in food companies. FAW is an important social issue, yet it is difficult to define and measure, meaning that it is difficult for companies to demonstrate accountability. The authors investigate a proposed solution, the Business Benchmark on Farm Animal Welfare (BBFAW), and how it has disrupted the informal rules or culture of the market. The research questions centre on the process of response to BBFAW and the necessary characteristics for BBFAW to play a performative role in the market. Design/methodology/approach This paper employs an analysis of published BBFAW reports (2012–2017) and case study interviews in five BBFAW firms, in order to address the research questions. Findings The authors present evidence of a dynamic, repetitive process, starting with recognition of the importance of FAW and BBFAW, followed by internal discussions and the commitment of resources, and changes in communication to external stakeholders. Three necessary characteristics for performativity are proposed: common language, building networks and expanding markets. Originality/value This paper reflects a socially important issue that is under-represented in the accounting literature. The results provide an insight into the use of external accounts to drive collaboratively the social change agenda. The performativity process and identified characteristics contribute to expanding this literature in the accounting domain.

scholarly journals Role of IncP-1β Plasmids pWDL7::rfpand pNB8c in Chloroaniline Catabolism as Determined by Genomic and Functional Analyses

2011 ◽  
Vol 78 (3) ◽  
pp. 828-838 ◽  
Author(s):  
J. E. Król ◽  
J. T. Penrod ◽  
H. McCaslin ◽  
L. M. Rogers ◽  
H. Yano ◽  
...  
Keyword(s):  
Single Copy ◽  
Degradation Pathway ◽  
Bacterial Degradation ◽  
Ring Cleavage ◽  
Close Relative ◽  
Broad Host Range ◽  
Content Type ◽  
Aromatic Ring Cleavage ◽  
Functional Analyses

ABSTRACTBroad-host-range catabolic plasmids play an important role in bacterial degradation of man-made compounds. To gain insight into the role of these plasmids in chloroaniline degradation, we determined the first complete nucleotide sequences of an IncP-1 chloroaniline degradation plasmid, pWDL7::rfpand its close relative pNB8c, as well as the expression pattern, function, and bioaugmentation potential of the putative 3-chloroaniline (3-CA) oxidation genes. Based on phylogenetic analysis of backbone proteins, both plasmids are members of a distinct clade within the IncP-1β subgroup. The plasmids are almost identical, but whereas pWDL7::rfpcarries a duplicate inverted catabolic transposon, Tn6063, containing a putative 3-CA oxidation gene cluster,dcaQTA1A2BR, pNB8c contains only a single copy of the transposon. No genes for an aromatic ring cleavage pathway were detected on either plasmid, suggesting that only the upper 3-CA degradation pathway was present. ThedcaA1A2Bgene products expressed from a high-copy-number vector were shown to convert 3-CA to 4-chlorocatechol inEscherichia coli. Slight differences in thedcapromoter region between the plasmids and lack of induction of transcription of the pNB8cdcagenes by 3-CA may explain previous findings that pNB8C does not confer 3-CA transformation. Bioaugmentation of activated sludge with pWDL7::rfpaccelerated removal of 3-CA, but only in the presence of an additional carbon source. Successful bioaugmentation requires complementation of the upper pathway genes with chlorocatechol cleavage genes in indigenous bacteria. The genome sequences of these plasmids thus help explain the molecular basis of their catabolic activities.

scholarly journals Resveratrol as a Growth Substrate for Bacteria from the Rhizosphere

2018 ◽  
Vol 84 (10) ◽  
Author(s):  
Zohre Kurt ◽  
Marco Minoia ◽  
Jim C. Spain
Keyword(s):  
Antioxidant Properties ◽  
Physiological Role ◽  
Bacterial Degradation ◽  
Ecological Role ◽  
Plant Metabolites ◽  
Natural Habitats ◽  
Content Type ◽  
Secondary Plant Metabolites ◽  
Degrading Bacteria

ABSTRACT Resveratrol is among the best-known secondary plant metabolites because of its antioxidant, anti-inflammatory, and anticancer properties. It also is an important allelopathic chemical widely credited with the protection of plants from pathogens. The ecological role of resveratrol in natural habitats is difficult to establish rigorously, because it does not seem to accumulate outside plant tissue. It is likely that bacterial degradation plays a key role in determining the persistence, and thus the ecological role, of resveratrol in soil. Here, we report the isolation of an Acinetobacter species that can use resveratrol as a sole carbon source from the rhizosphere of peanut plants. Both molecular and biochemical techniques indicate that the pathway starts with the conversion of resveratrol to 3,5-dihydroxybenzaldehyde and 4-hydroxybenzaldehyde. The aldehydes are oxidized to substituted benzoates that subsequently enter central metabolism. The gene that encodes the enzyme responsible for the oxidative cleavage of resveratrol was cloned and expressed in Escherichia coli to establish its function. Its physiological role in the resveratrol catabolic pathway was established by knockouts and by the reverse transcription-quantitative PCR (RT-qPCR) demonstration of expression during growth on resveratrol. The results establish the presence and capabilities of resveratrol-degrading bacteria in the rhizosphere of the peanut plants and set the stage for studies to evaluate the role of the bacteria in plant allelopathy. IMPORTANCE In addition to its antioxidant properties, resveratrol is representative of a broad array of allelopathic chemicals produced by plants to inhibit competitors, herbivores, and pathogens. The bacterial degradation of such chemicals in the rhizosphere would reduce the effects of the chemicals. Therefore, it is important to understand the activity and ecological role of bacteria that biodegrade resveratrol near the plants that produce it. This study describes the isolation from the peanut rhizosphere of bacteria that can grow on resveratrol. The characterization of the initial steps in the biodegradation process sets the stage for the investigation of the evolution of the catabolic pathways responsible for the biodegradation of resveratrol and its homologs.

scholarly journals On-farm biopurification systems: role of white rot fungi in depuration of pesticide-containing wastewaters

2013 ◽  
Vol 345 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Carlos E. Rodríguez-Rodríguez ◽  
Víctor Castro-Gutiérrez ◽  
Juan Salvador Chin-Pampillo ◽  
Karla Ruiz-Hidalgo
Keyword(s):  
White Rot Fungi ◽  
White Rot ◽  
On Farm ◽  
Biopurification Systems

Long-term management of patients with multiple brain metastases after shaped beam radiosurgery

2004 ◽  
pp. 406-412
Author(s):  
Paul Okunieff ◽  
Michael C. Schell ◽  
Russell Ruo ◽  
E. Ronald Hale ◽  
Walter G. O'Dell ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Tumor Control ◽  
Content Type ◽  
Negative Results ◽  
Multiple Metastases ◽  
Extracranial Disease ◽  
Successful Control ◽  
The Brain

✓ The role of radiosurgery in the treatment of patients with advanced-stage metastatic disease is currently under debate. Previous randomized studies have not consistently supported the use of radiosurgery to treat patients with numbers of brain metastases. In negative-results studies, however, intracranial tumor control was high but extracranial disease progressed; thus, patient survival was not greatly affected, although neurocognitive function was generally maintained until death. Because the future promises improved systemic (extracranial) therapy, the successful control of brain disease is that much more crucial. Thus, for selected patients with multiple metastases to the brain who remain in good neurological condition, aggressive lesion-targeting radiosurgery should be very useful. Although a major limitation to success of this therapy is the lack of control of extracranial disease in most patients, it is clear that well-designed, aggressive treatment substantially decreases the progression of brain metastases and also improves neurocognitive survival. The authors present the management and a methodology for rational treatment of a patient with breast cancer who has harbored 24 brain metastases during a 3-year period.

scholarly journals Vulnerable adults in police custody

2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins
Keyword(s):  
Design Methodology ◽  
Research Literature ◽  
Police Custody ◽  
England And Wales ◽  
Content Type ◽  
Increased Risk ◽  
Vulnerable Adults

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.

Financial access and economic development: the moderating role of financial consumer protection

2019 ◽  
Vol 15 (4) ◽  
pp. 406-424 ◽  
Author(s):  
Maryam Kriese ◽  
Joshua Yindenaba Abor ◽  
Elikplimi Agbloyor
Keyword(s):  
Economic Development ◽  
World Bank ◽  
Financial Literacy ◽  
Compliance Monitoring ◽  
Financial Access ◽  
Policy Makers ◽  
Content Type ◽  
The World Bank ◽  
Moderating Role

Purpose The purpose of this paper is to examine the moderating role of financial consumer protection (FCP) in the access–development nexus. Design/methodology/approach The study is based on cross-country data on 102 countries surveyed in the World Bank Global Survey on FCP and Financial Literacy (2013). The White heteroscedasticity adjusted regressions and Two-stage least squares regressions (2SLS) are used for the estimation. Findings Interactions between FCP regulations that foster fair treatment, disclosure, dispute resolution and recourse and financial access have positive net effects on economic development. However, there is no sufficient evidence to suggest that interactions between financial access and enforcement and compliance monitoring regulations have a significant effect on economic development. Practical implications First, policy makers should continue with efforts aimed at instituting FCP regimes as part of strategies aimed at broadening access to financial services for enhanced economic development. Second, instituting FCP regimes per se may not be enough. Policy makers need to consider possible intervening factors such as the provision of adequate resources and supervisory authority, for compliance monitoring and enforcement to achieve the expected positive effect on economic development. Originality/value This study extends evidence in the law–finance–growth literature by providing empirical evidence on the effect of legal institution specific to the protection of retail financial consumers on the access–development nexus using a nouvel data set, the World Bank Global survey on FCP and Financial Literacy (2013).

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