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Rahmati F, Sethi D, Shu W, Asgari Lajayer B, Mosaferi M, Thomson A, Price GW. Advances in microbial exoenzymes bioengineering for improvement of bioplastics degradation. Chemosphere 2024; 355:141749. [PMID: 38521099 DOI: 10.1016/j.chemosphere.2024.141749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 03/06/2024] [Accepted: 03/16/2024] [Indexed: 03/25/2024]
Abstract
Plastic pollution has become a major global concern, posing numerous challenges for the environment and wildlife. Most conventional ways of plastics degradation are inefficient and cause great damage to ecosystems. The development of biodegradable plastics offers a promising solution for waste management. These plastics are designed to break down under various conditions, opening up new possibilities to mitigate the negative impact of traditional plastics. Microbes, including bacteria and fungi, play a crucial role in the degradation of bioplastics by producing and secreting extracellular enzymes, such as cutinase, lipases, and proteases. However, these microbial enzymes are sensitive to extreme environmental conditions, such as temperature and acidity, affecting their functions and stability. To address these challenges, scientists have employed protein engineering and immobilization techniques to enhance enzyme stability and predict protein structures. Strategies such as improving enzyme and substrate interaction, increasing enzyme thermostability, reinforcing the bonding between the active site of the enzyme and substrate, and refining enzyme activity are being utilized to boost enzyme immobilization and functionality. Recently, bioengineering through gene cloning and expression in potential microorganisms, has revolutionized the biodegradation of bioplastics. This review aimed to discuss the most recent protein engineering strategies for modifying bioplastic-degrading enzymes in terms of stability and functionality, including enzyme thermostability enhancement, reinforcing the substrate binding to the enzyme active site, refining with other enzymes, and improvement of enzyme surface and substrate action. Additionally, discovered bioplastic-degrading exoenzymes by metagenomics techniques were emphasized.
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Affiliation(s)
- Farzad Rahmati
- Department of Microbiology, Faculty of Science, Qom Branch, Islamic Azad University (IAU), Qom 37185364, Iran
| | - Debadatta Sethi
- Sugarcane Research Station, Odisha University of Agriculture and Technology, Nayagarh, India
| | - Weixi Shu
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | | | - Mohammad Mosaferi
- Health and Environment Research Center, Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Allan Thomson
- Perennia Food and Agriculture Corporation., 173 Dr. Bernie MacDonald Dr., Bible Hill, Truro, NS, B6L 2H5, Canada
| | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada.
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Le Q, Price GW. A review of the influence of heat drying, alkaline treatment, and composting on biosolids characteristics and their impacts on nitrogen dynamics in biosolids-amended soils. Waste Manag 2024; 176:85-104. [PMID: 38266478 DOI: 10.1016/j.wasman.2024.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 01/02/2024] [Accepted: 01/12/2024] [Indexed: 01/26/2024]
Abstract
Application of biosolids to agricultural land has gained increasing attention due to their rich nutrient content. There are a variety of treatment processes for converting sewage sludge to biosolids. Different treatment processes can change the physicochemical properties of the raw sewage sludge and affect the dynamics of nutrient release in biosolids-amended soils. This paper reviews heat drying, alkaline treatment, and composting as biosolids treatment processes and discusses the effects of these treatments on biosolid nitrogen (N) content and availability. Most N in the biosolids remain in organic forms, regardless of biosolids treatment type but considerable variation exists in the mean values of total N and mineralizable N across different types of biosolids. The highest mean total N content was recorded in heat-dried biosolids (HDB) (4.92%), followed by composted biosolids (CB) (2.25%) and alkaline-treated biosolids (ATB) (2.14%). The mean mineralizable N value was similar between HDB and ATB, with a broader range of mineralizable N in ATB. The lowest N availability was observed in CB. Although many models have been extensively studied for predicting potential N mineralization in soils amended with organic amendments, limited research has attempted to model soil N mineralization following biosolids application. With biosolids being a popular, economical, and eco-friendly alternative to chemical N-fertilizers, understanding biosolids treatment effects on biosolids properties is important for developing a sound biosolids management system. Moreover, modeling N mineralization in biosolids-amended soils is essential for the adoption of sustainable farming practices that maximize the agronomic value of all types of biosolids.
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Affiliation(s)
- Qianhan Le
- Department of Engineering, Faculty of Agriculture, Dalhousie University, PO Box 550, Truro, NS B2N 5E3, Canada
| | - G W Price
- Department of Engineering, Faculty of Agriculture, Dalhousie University, PO Box 550, Truro, NS B2N 5E3, Canada.
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Obi-Njoku O, Boh MY, Smith W, Grant B, Flemming C, Price GW, Hernandez-Ramirez G, Burton D, Whalen JK, Clark OG. A comparison of Tier 1, 2, and 3 methods for quantifying nitrous oxide emissions from soils amended with biosolids. Sci Total Environ 2024; 915:169639. [PMID: 38181952 DOI: 10.1016/j.scitotenv.2023.169639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 12/08/2023] [Accepted: 12/21/2023] [Indexed: 01/07/2024]
Abstract
Municipal biosolids are a nitrogen (N)-rich agricultural fertilizer which may emit nitrous oxide (N2O) after rainfall events. Due to sparse empirical data, there is a lack of biosolids-specific N2O emission factors to determine how land-applied biosolids contribute to the national greenhouse gas inventory. This study estimated N2O emissions from biosolids-amended land in Canada using Tier 1, Tier 2 (Canadian), and Tier 3 (Denitrification and Decomposition model [DNDC]) methodologies recommended by the Intergovernmental Panel on Climate Change (IPCC). Field data was from replicated plots at 8 site-years between 2017 and 2019 in the provinces of Quebec, Nova Scotia and Alberta, Canada, representing three distinct ecozones. Municipal biosolids were the major N source for the crop, applied as mesophilic anaerobically digested biosolids, composted biosolids, or alkaline-stabilized biosolids alone or combined with an equal amount of urea-N fertilizer to meet the crop N requirements. Fluxes of N2O were measured during the growing season with manual chambers and compared to N2O emissions estimated using the IPCC methods. In all site-years, the mean emission of N2O in the growing season was greater with digested biosolids than other biosolids sources or urea fertilizer alone. The emissions of N2O in the growing season were similar with composted or alkaline-stabilized biosolids, and no greater than the unfertilized control. The best estimates of N2O emissions, relative to measured values, were with the Tier 3 > adapted Tier 2 with biosolids-specific correction factors > standard Tier 2 = Tier 1 methods of the IPCC, according to the root mean square error statistic. The Tier 3 IPCC method was the best estimator of N2O emissions in the Canadian ecozones evaluated in this study. These results will be used to improve methods for estimating N2O emissions from agricultural soils amended with biosolids and to generate more accurate GHG inventories.
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Affiliation(s)
- Okenna Obi-Njoku
- Department of Bioresource Engineering, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Michael Yongha Boh
- Department of Bioresource Engineering, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Ward Smith
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON, K1A 0C6, Canada
| | - Brian Grant
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON, K1A 0C6, Canada
| | - Corey Flemming
- Pollutant Inventories and Reporting Division, Environment and Climate Change Canada, 351 St-Joseph Blvd, Gatineau, QC, K1A 0H3, Canada
| | - G W Price
- Department of Engineering, Faculty of Agriculture, Dalhousie University, PO Box 550, Truro, NS, B2N 5E3, Canada
| | - Guillermo Hernandez-Ramirez
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada
| | - David Burton
- Department of Engineering, Faculty of Agriculture, Dalhousie University, PO Box 550, Truro, NS, B2N 5E3, Canada
| | - Joann K Whalen
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - O Grant Clark
- Department of Bioresource Engineering, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada.
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Sharma R, Sharma N, Prashar A, Hansa A, Asgari Lajayer B, Price GW. Unraveling the plethora of toxicological implications of nanoparticles on living organisms and recent insights into different remediation strategies: A comprehensive review. Sci Total Environ 2024; 906:167697. [PMID: 37832694 DOI: 10.1016/j.scitotenv.2023.167697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 10/05/2023] [Accepted: 10/07/2023] [Indexed: 10/15/2023]
Abstract
Increased use of nanoscale particles have benefited many industries, including medicine, electronics, and environmental cleaning. These particles provide higher material performance, greater reactivity, and improved drug delivery. However, the main concern is the generation of nanowastes that can spread in different environmental matrices, posing threat to our environment and human health. Nanoparticles (NPs) have the potential to enter the food chain through a variety of pathways, including agriculture, food processing, packaging, and environmental contamination. These particles can negatively impact plant and animal physiology and growth. Due to the assessment of their environmental damage, nanoparticles are the particles of size between 1 and 100 nm that is the recent topic to be discussed. Nanoparticles' absorption, distribution, and toxicity to plants and animals can all be significantly influenced by their size, shape, and surface chemistry. Due to their absorptive capacity and potential to combine with other harmful substances, they can alter the metabolic pathways of living organisms. Nevertheless, despite the continuous research and availability of data, there are still knowledge gaps related to the ecotoxicology, prevalence and workable ways to address the impact of nanoparticles. This review focuses on the impact of nanoparticles on different organisms and the application of advanced techniques to remediate ecosystems using hyperaccumulator plant species. Future considerations are explored around nano-phytoremediation, as an eco-friendly, convenient and cost effective technology that can be applied at field scales.
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Affiliation(s)
- Ritika Sharma
- Department of Botany, Central University of Jammu, Samba, Jammu and Kashmir, India.
| | - Nindhia Sharma
- Department of Botany, Central University of Jammu, Samba, Jammu and Kashmir, India
| | - Abhinav Prashar
- Department of Botany, Central University of Jammu, Samba, Jammu and Kashmir, India
| | - Abish Hansa
- Department of Botany, Central University of Jammu, Samba, Jammu and Kashmir, India
| | | | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada
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Sepehri S, Abdoli S, Asgari Lajayer B, Astatkie T, Price GW. Changes in phytochemical properties and water use efficiency of peppermint (Mentha piperita L.) using superabsorbent polymer under drought stress. Sci Rep 2023; 13:21989. [PMID: 38081886 PMCID: PMC10713560 DOI: 10.1038/s41598-023-49452-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 12/08/2023] [Indexed: 12/18/2023] Open
Abstract
Water consumption management and the application of advanced techniques in the agricultural sector can significantly contribute to the efficient utilization of limited water resources. This can be achieved by improving soil texture, increasing water retention, reducing erosion, and enhancing seedling germination through the use of superabsorbent polymers. This study aimed to investigate the effect of Aquasource superabsorbent (AS) on the morphological characteristics, phytochemical properties, antioxidant content, and water use efficiency of peppermint. It was conducted under different irrigation management and using different superabsorbent levels. Therefore, a 3 × 4 factorial design was used to determine the effects of irrigation intervals (2-, 4-, and 6-day) and different levels of AS amount (zero [control], 0.5, 1, and 2 wt%). The effects of these factors on various parameters (morphological characteristics, essential oil percentage, nutrient, protein, proline, carotenoid, antioxidant, and chlorophyll content, leaf area index, relative water content, and water use efficiency [WUE]) were evaluated. The results showed that morphological characteristics and essential oil percentage decreased significantly under drought stress (increasing the irrigation intervals). However, the addition of 0.5 (wt%) AS improved plant growth conditions. Increasing the amount of superabsorbent used to 1 and 2 (wt%) decreased the measured traits, which indicates the creation of unsuitable conditions for plant growth. AS application improved the growth of the root more than the leaf yield of peppermint. A 0.5 (wt%) addition of AS resulted in root length increases of 3, 13, and 15%, respectively, at irrigation intervals of 2, 4, and 6 days, respectively. Additionally, at 0.5 (wt%) AS, root weight increased by 8, 15, and 16% in 2-, 4-, and 6-day irrigation intervals, respectively. Also, the height of the plant increased by 3, 5, and 17% at 2-, 4-, and 6-day irrigation intervals when 0.5 (wt%) of AS was used compared to the control. As well, essential oil percentage increased by 2.14, 2.06, and 1.63% at 2-, 4-, and 6-day irrigation intervals. The nutrient and protein contents decreased as irrigation intervals and AS usage increased, indicating a similar trend. However, compared with the control, the addition of 0.5 (wt%) of AS resulted in some improvements in nutrients and protein. The highest WUE (3.075 kg m-3) was attained in the 4-day irrigation interval and 1 wt% AS addition. This was followed closely by the 2-day irrigation interval with 1 wt% AS addition at 3.025 kg m-3, and the 4-day irrigation interval with 0.5 wt% AS addition, which reached 2.941 kg m-3. Overall, the use of AS in appropriate amounts (0.5 wt%) can reduce water consumption and enhance essential oil yield and WUE in peppermint cultivation in water-scarce arid and semi-arid regions.
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Affiliation(s)
- Saloome Sepehri
- Agricultural Engineering Research Institute (AERI), Agricultural Research, Education and Extension Organization (AREEO), P.O. Box 31585-845, Karaj, Iran.
| | - Sima Abdoli
- Department of Soil Science and Engineering, Shahid Chamran University of Ahvaz, Ahvaz, 6135743136, Iran.
| | | | - Tess Astatkie
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
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6
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Dehghanian Z, Asgari Lajayer B, Biglari Quchan Atigh Z, Nayeri S, Ahmadabadi M, Taghipour L, Senapathi V, Astatkie T, Price GW. Micro (nano) plastics uptake, toxicity and detoxification in plants: Challenges and prospects. Ecotoxicol Environ Saf 2023; 268:115676. [PMID: 37979355 DOI: 10.1016/j.ecoenv.2023.115676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/05/2023] [Accepted: 11/09/2023] [Indexed: 11/20/2023]
Abstract
Plastic pollution has emerged as a global challenge affecting ecosystem health and biodiversity conservation. Terrestrial environments exhibit significantly higher plastic concentrations compared to aquatic systems. Micro/nano plastics (MNPs) have the potential to disrupt soil biology, alter soil properties, and influence soil-borne pathogens and roundworms. However, limited research has explored the presence and impact of MNPs on aquaculture systems. MNPs have been found to inhibit plant and seedling growth and affect gene expression, leading to cytogenotoxicity through increased oxygen radical production. The article discusses the potential phytotoxicity process caused by large-scale microplastics, particularly those unable to penetrate cell pores. It also examines the available data, albeit limited, to assess the potential risks to human health through plant uptake.
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Affiliation(s)
- Zahra Dehghanian
- Department of Biotechnology, Faculty of Agriculture, Azarbaijan Shahid Madani University, Tabriz, Iran.
| | | | - Zahra Biglari Quchan Atigh
- Department of Civil Engineering and Smart Cities, College of Engineering, Shantou University, Shantou, Guangdong 515063, China.
| | - Shahnoush Nayeri
- SP-Lab., ASEPE Company, Industrial Park of Advanced Technologies, Tabriz, Iran.
| | - Mohammad Ahmadabadi
- Department of Biotechnology, Faculty of Agriculture, Azarbaijan Shahid Madani University, Tabriz, Iran.
| | - Leila Taghipour
- Department of Horticultural Science, College of Agriculture, Jahrom University, PO Box: 74135-111, Jahrom, Iran.
| | | | - Tess Astatkie
- Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada.
| | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada.
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Shu W, Price GW, Jamieson R, Lake C. Simulating fate and transport of non-steroidal anti-inflammatory drugs using Root Zone Water Quality Model 2. J Environ Qual 2023; 52:1178-1192. [PMID: 37661655 DOI: 10.1002/jeq2.20509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/28/2023] [Indexed: 09/05/2023]
Abstract
The fate and transport of non-steroidal anti-inflammatory drugs (NSAIDs) in soil are determined by various processes, and the complexity of the system lends itself to the use of computer simulation models to help understand it. This study demonstrated the first attempt to use empirical data from lab incubation and field studies to parameterize and test a process-based agricultural systems model, Root Zone Water Quality Model 2 (RZWQM2), to simulate the fate and transport of naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF) in field-based lysimeters amended with alkaline-treated biosolids (ATBs). The model calibrated for the soil-water balance module and contaminant transport module was used to predict water seepage through the soil profile in 2017 and 2018 within a 15% error of the field measured data, with model performance statistics such as Nash-Sutcliffe model efficiency (NSE) and R2 all greater than 0.70. The overall predicted percent recovery of initial spiked NSAIDs in both soil and water samples, after further calibration of the contaminant transport module, was within the same order of magnitude as the measured data. The model underestimated the percent recovery of initial spiked NSAIDs at the 30- to 55-cm soil depth for all treatments on day 3. The calibrated soil subsurface aerobic half-lives of NPX and IBF were found to be considerably lower than their laboratory-measured half-lives obtained from the incubation study. The overall performance of RZWQM2 in simulating the soil hydrology and behavior of NSAIDs in soil profiles receiving various rates of ATB amendments was satisfactory.
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Affiliation(s)
- Weixi Shu
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | - Gordon W Price
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | - Rob Jamieson
- Department of Civil and Resource Engineering, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Craig Lake
- Department of Civil and Resource Engineering, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
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Shahi Khalaf Ansar B, Kavusi E, Dehghanian Z, Pandey J, Asgari Lajayer B, Price GW, Astatkie T. Removal of organic and inorganic contaminants from the air, soil, and water by algae. Environ Sci Pollut Res Int 2023; 30:116538-116566. [PMID: 35680750 DOI: 10.1007/s11356-022-21283-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Rapid increases in human populations and development has led to a significant exploitation of natural resources around the world. On the other hand, humans have come to terms with the consequences of their past mistakes and started to address current and future resource utilization challenges. Today's primary challenge is figuring out and implementing eco-friendly, inexpensive, and innovative solutions for conservation issues such as environmental pollution, carbon neutrality, and manufacturing effluent/wastewater treatment, along with xenobiotic contamination of the natural ecosystem. One of the most promising approaches to reduce the environmental contamination load is the utilization of algae for bioremediation. Owing to their significant biosorption capacity to deactivate hazardous chemicals, macro-/microalgae are among the primary microorganisms that can be utilized for phytoremediation as a safe method for curtailing environmental pollution. In recent years, the use of algae to overcome environmental problems has advanced technologically, such as through synthetic biology and high-throughput phenomics, which is increasing the likelihood of attaining sustainability. As the research progresses, there is a promise for a greener future and the preservation of healthy ecosystems by using algae. They might act as a valuable tool in creating new products.
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Affiliation(s)
- Behnaz Shahi Khalaf Ansar
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Elaheh Kavusi
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Zahra Dehghanian
- Department of Biotechnology, Faculty of Agriculture, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Janhvi Pandey
- Division of Agronomy and Soil Science, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow, Uttar Pradesh, India
| | - Behnam Asgari Lajayer
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
| | - Gordon W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | - Tess Astatkie
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
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Bagheri Novair S, Cheraghi M, Faramarzi F, Asgari Lajayer B, Senapathi V, Astatkie T, Price GW. Reviewing the role of biochar in paddy soils: An agricultural and environmental perspective. Ecotoxicol Environ Saf 2023; 263:115228. [PMID: 37423198 DOI: 10.1016/j.ecoenv.2023.115228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/19/2023] [Accepted: 07/01/2023] [Indexed: 07/11/2023]
Abstract
The main challenge of the twenty-first century is to find a balance between environmental sustainability and crop productivity in a world with a rapidly growing population. Soil health is the backbone of a resilient environment and stable food production systems. In recent years, the use of biochar to bind nutrients, sorption of pollutants, and increase crop productivity has gained popularity. This article reviews key recent studies on the environmental impacts of biochar and the benefits of its unique physicochemical features in paddy soils. This review provides critical information on the role of biochar properties on environmental pollutants, carbon and nitrogen cycling, plant growth regulation, and microbial activities. Biochar improves the soil properties of paddy soils through increasing microbial activities and nutrient availability, accelerating carbon and nitrogen cycle, and reducing the availability of heavy metals and micropollutants. For example, a study showed that the application of a maximum of 40 t ha-1 of biochar from rice husks prior to cultivation (at high temperature and slow pyrolysis) increases nutrient utilization and rice grain yield by 40%. Biochar can be used to minimize the use of chemical fertilizers to ensure sustainable food production.
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Affiliation(s)
- Sepideh Bagheri Novair
- Department of Soil Science, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.
| | - Meysam Cheraghi
- Department of Soil Science, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.
| | - Farzaneh Faramarzi
- Department of Agronomy and Plant Breeding, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.
| | | | | | - Tess Astatkie
- Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada.
| | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada.
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10
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Mohammadi Alagoz S, Hadi H, Toorchi M, Pawłowski TA, Asgari Lajayer B, Price GW, Farooq M, Astatkie T. Morpho-physiological responses and growth indices of triticale to drought and salt stresses. Sci Rep 2023; 13:8896. [PMID: 37264097 DOI: 10.1038/s41598-023-36119-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/30/2023] [Indexed: 06/03/2023] Open
Abstract
Salinity and drought are two major abiotic stresses challenging global crop production and food security. In this study, the effects of individual and combined effects of drought (at different phenological stages) and salt stresses on growth, morphology, and physiology of triticale were evaluated. For this purpose, a 3 x 4 factorial design in three blocks experiment was conducted. The stress treatments included three levels of salinity (0, 50, and 100 mM NaCl) and four levels of drought (regular irrigation as well as irrigation disruption at heading, flowering, and kernel extension stages). The stresses, individual as well as combined, caused a significant decrease in chlorophyll contents, total dry matter, leaf area index, relative water content, and grain yield of triticale. In this regard, the highest reduction was recorded under combined stresses of 100 mM NaCl and drought stress at flowering. However, an increase in soluble sugars, leaf free proline, carotenoid contents, and electrolyte leakage was noted under stress conditions compared to the control. In this regard, the highest increase in leaf free proline, soluble sugars, and carotenoid contents were noted under the combination of severe salinity and drought stress imposed at the flowering stage. Investigating the growth indices in severe salinity and water deficit stress in different phenological stages shows the predominance of ionic stress over osmotic stress under severe salinity. The highest grain yield was observed under non-saline well-watered conditions whereas the lowest grain yield was recorded under severe salinity and drought stress imposed at the flowering stage. In conclusion, the flowering stage was more sensitive than the heading and kernel extension stages in terms of water deficit. The impact of salinity and water deficit was more pronounced on soluble sugars and leaf free proline; so, these criteria can be used as physiological indicators for drought and salinity tolerance in triticale.
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Affiliation(s)
- Soheyla Mohammadi Alagoz
- Department of Plant Production and Genetics, Faculty of Agriculture, Urmia University, Urmia, Iran.
| | - Hashem Hadi
- Department of Plant Production and Genetics, Faculty of Agriculture, Urmia University, Urmia, Iran
| | - Mahmoud Toorchi
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | | | | | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | - Muhammad Farooq
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al-Khoud 123, Muscat, Oman
| | - Tess Astatkie
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
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Shu W, Price GW, Jamieson R, Lake C. Effect of biosolids amendment on the fate and mobility of non-steroidal anti-inflammatory drugs (NSAIDs) in a field-based lysimeter cell study. Environ Pollut 2023; 331:121939. [PMID: 37263567 DOI: 10.1016/j.envpol.2023.121939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 06/03/2023]
Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used globally to treat and prevent illness. Biosolids change physico-chemical characteristics of soil and can affect the mobility of NSAIDs. A field-based lysimeter study evaluated the effect of three rates (0, 7, and 28 Mg ha-1) of alkaline treated biosolids (ATB) on the leaching potential of naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF) over 34 days in a sandy loam textured soil. Although all three NSAIDs in the lysimeter cells vertically migrated to deeper soil depths after spiking, the sum of all NPX, IBF, and KTF detected in the leachate samples from all treatments were only 0.03%, 0.02%, and 0.04% of the initial spiking mass to the surface soil, respectively. A mass balance analysis indicated a low accumulation of these compounds in the soil at the end of the study (Day 34) from all treatments with only 4.8%, 0.5%, and 0.7% of initial spiked NPX, IBF, and KTF, respectively. Application of ATB significantly increased soil pH and organic matter (OM) content of the soils but did not impact retention of the compounds in the soil profile. Overall, all three NSAIDs in the present study presented low mobility in the loamy sand textured agricultural soil.
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Affiliation(s)
- W Shu
- Department of Engineering, Dalhousie University Faculty of Agriculture, PO Box 550, Truro, NS, B2N 5E3, Canada
| | - G W Price
- Department of Engineering, Dalhousie University Faculty of Agriculture, PO Box 550, Truro, NS, B2N 5E3, Canada.
| | - R Jamieson
- Department of Civil and Resource Engineering, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - C Lake
- Department of Civil and Resource Engineering, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
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Huang J, Liu C, Price GW, Wang Y. Zinc and cadmium change the metabolic activities and vegetable cellulose degradation of Bacillus cellulasensis in vegetable soils. Environ Sci Pollut Res Int 2023:10.1007/s11356-023-27597-8. [PMID: 37247150 DOI: 10.1007/s11356-023-27597-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/09/2023] [Indexed: 05/30/2023]
Abstract
Bacillus cellulasensis Zn-B isolated from vegetable soil was highly adaptable to Zinc (Zn) and Cadmium (Cd). Cd, but not Zn, adversely affected the total protein spectrum and functional groups of Bacillus cellulasensis Zn-B. Up to 31 metabolic pathways and 216 metabolites of Bacillus cellulasensis Zn-B were significantly changed by Zn and Cd (Zn&Cd). Some metabolic pathways and metabolites related to functional groups of sulfhydryl (-SH) and amine (-NH-) metabolism were enhanced by Zn&Cd addition. The cellulase activity of Bacillus cellulasensis Zn-B was up to 8.58 U mL-1, increased to 10.77 U mL-1 in Bacillus cellulasensis Zn-B + 300 mg L-1 Zn, and maintained at 6.13 U mL-1 in Bacillus cellulasensis Zn-B + 50 mg L-1 Cd. The vegetables' cellulose content was decreased by 25.05-52.37% and 40.28-70.70% under the action of Bacillus cellulasensis Zn-B and Bacillus cellulasensis Zn-B + 300 mg L-1 Zn. Those results demonstrated that Zn could significantly enhance cellulase activity and biodegradability of Bacillus cellulasensis Zn-B to vegetable cellulose. Bacillus cellulasensis Zn-B can survive in vegetable soil accumulated with Zn&Cd. The tolerance concentration and adsorption capacity of Bacillus cellulasensis Zn-B to Zn were up to 300 mg L-1 and 56.85%, indicating that Bacillus cellulasensis Zn-B acting as a thermostability biological agent had an essential advantage in accelerating the degradation of discarded vegetables by Zn and were beneficial to maintain organic matter content of vegetable soil.
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Affiliation(s)
- Jiaqing Huang
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350013, China
- Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou, 350013, China
| | - Cenwei Liu
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350013, China
- Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou, 350013, China
| | - Gordon W Price
- Department of Engineering, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | - Yixiang Wang
- Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou, 350013, China.
- Institute of Soil and Fertilizer, Fujian Academy of Agricultural Sciences, Fuzhou, 350013, China.
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Huang J, Ye J, Gao W, Liu C, Price GW, Li Y, Wang Y. Tea biochar-immobilized Ralstonia Bcul-1 increases nitrate nitrogen content and reduces the bioavailability of cadmium and chromium in a fertilized vegetable soil. Sci Total Environ 2023; 866:161381. [PMID: 36621509 DOI: 10.1016/j.scitotenv.2022.161381] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 12/08/2022] [Accepted: 12/31/2022] [Indexed: 06/17/2023]
Abstract
Pyrolytic biochar (PL-BC, pyrochar) and hydrothermal biochar (HT-BC, hydrochar) derived from branches and leaves of tea plants had different pH, electrical conductivity (EC), total carbon nitrogen content, BET surface area, total pore volume, average pore diameter, and functional groups. HT-BC had a larger specific surface area and more functional groups than PL-BC. Ralstonia Bcul-1 (R-B) was the dominant and functional bacteria in a fertilized vegetable soil supplemented with TBB-immobilized R-B (TBB + R-B). R-B vitality was more closely related to BET surface area, total pore volume, and functional groups of tea-based biochar (TBB: PL-BC and HT-BC). R-B was able to maintain high oxidase activity. R-B and TBB + R-B can increase the activities of urease and peroxidase in vegetable soil playing an essential role in the biotransformation of ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N). TBB was able to simultaneously increase the content of NO3--N and NH4+-N, and TBB + R-B also significantly increased NO3--N content but decreased NH4+-N content in a fertilized vegetable soil. These results indicated that R-B promoted nitrification in the soil, i.e. conversion of NH4+-N into NO3--N, by enhancing the activities of urease and peroxidase. R-B had high adsorption capacity for cadmium (Cd) and chromium (Cr) (Cd&Cr: Cd and Cr). Moreover, TBB + R-B was able to convert weak acid extractable and reducible Cd&Cr into a more stable residual fraction and oxidizable Cd&Cr. The overall effect of the treatments was to reduce plant uptake of Cd&Cr by cabbage. TBB + R-B significantly promoted R-B growth, changed inorganic nitrogen speciation, increased NO3--N supply, reduced Cd&Cr bioavailability, and decreased plant tissue Cd&Cr content.
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Affiliation(s)
- Jiaqing Huang
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - Jing Ye
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - Wenhui Gao
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - Cenwei Liu
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - G W Price
- Department of Engineering, Dalhousie University, Truro, NS B2N 5E3, Canada
| | - Yanchun Li
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - Yixiang Wang
- Institute of Soil and Fertilizer, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China.
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Kavusi E, Shahi Khalaf Ansar B, Ebrahimi S, Sharma R, Ghoreishi SS, Nobaharan K, Abdoli S, Dehghanian Z, Asgari Lajayer B, Senapathi V, Price GW, Astatkie T. Critical review on phytoremediation of polyfluoroalkyl substances from environmental matrices: Need for global concern. Environ Res 2023; 217:114844. [PMID: 36403653 DOI: 10.1016/j.envres.2022.114844] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 11/12/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Poly- and perfluoroalkyl substances (PFAS) are a class of emerging organic contaminants that are impervious to standard physicochemical treatments. The widespread use of PFAS poses serious environmental issues. PFAS pollution of soils and water has become a significant issue due to the harmful effects of these chemicals both on the environment and public health. Owing to their complex chemical structures and interaction with soil and water, PFAS are difficult to remove from the environment. Traditional soil remediation procedures have not been successful in reducing or removing them from the environment. Therefore, this review focuses on new phytoremediation techniques for PFAS contamination of soils and water. The bioaccumulation and dispersion of PFAS inside plant compartments has shown great potential for phytoremediation, which is a promising and unique technology that is realistic, cost-effective, and may be employed as a wide scale in situ remediation strategy.
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Affiliation(s)
- Elaheh Kavusi
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Behnaz Shahi Khalaf Ansar
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Samira Ebrahimi
- Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Ritika Sharma
- Department of Botany, Central University of Jammu, Jammu and Kashmir, India
| | - Seyede Shideh Ghoreishi
- Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | | | - Sima Abdoli
- Department of Soil Science and Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Zahra Dehghanian
- Department of Biotechnology, Faculty of Agriculture, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Behnam Asgari Lajayer
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
| | | | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | - Tess Astatkie
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
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15
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Obi-Njoku O, Boh MY, Smith W, Grant B, Price GW, Hussain N, Whalen JK, Clark OG. Greenhouse gas emissions following biosolids application to farmland: Estimates from the DeNitrification and DeComposition model. Sci Total Environ 2022; 823:153695. [PMID: 35143794 DOI: 10.1016/j.scitotenv.2022.153695] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Municipal wastewater sludge may be processed into biosolids and applied to farmland for crop production, rather than be disposed of in landfills. Biosolids supply plant nutrients and increase soil organic carbon but also contribute to the production of greenhouse gases (GHGs). Computational models must therefore be refined to estimate the contribution of these gases to national GHG inventories. The DeNitrification and DeComposition (DNDC) model was evaluated for processes regulating crop growth, GHGs and soil C&N dynamics to determine its suitability for informing policy decision-making and advancing Canada's GHG inventory. Three years (2017-2019) of data were collected from replicated corn (Zea mays L.) plots in Quebec, Canada. The plots received 120 kg of available N ha-1 y-1 in mesophilic anaerobically digested biosolids, composted biosolids, alkaline-stabilized biosolids, urea, or combinations of these, while control plots were left unfertilized. Treatments receiving digested biosolids emitted more nitrous oxide (N2O) during the growing season than other treatments, while carbon dioxide (CO2) emissions were similar between treatments. After calibration, DNDC estimates were within the 95% confidence interval of the measured variables. Correlation coefficients (r) indicated discrepancies in trends between the estimated and measured values for daily CO2 and N2O emissions. These emissions were underestimated in the early and mid-growing season of 2018. They were more variable from plots fertilized with composted or alkaline-stabilized biosolids than from those with digested biosolids. Annual N2O emissions (r = 0.8), crop yields (r = 0.5), and soil organic carbon (r = 0.4) were modelled with higher accuracy than cumulative CO2 emissions (r = 0.3) and total soil N (r = 0.1). These findings suggest that DNDC is suitable for estimating field-scale N2O emissions following biosolids application, but estimates of CO2 emissions could be improved, perhaps by disaggregating the biosolids from the soil organic matter pools in the decomposition subroutines.
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Affiliation(s)
- Okenna Obi-Njoku
- Department of Bioresource Engineering, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Michael Yongha Boh
- Department of Bioresource Engineering, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Ward Smith
- Agriculture and Agri-Food Canada, 960 Carling Ave, K.W. Neatby Building, ON K1A 0C6, Canada
| | - Brian Grant
- Agriculture and Agri-Food Canada, 960 Carling Ave, K.W. Neatby Building, ON K1A 0C6, Canada
| | - G W Price
- Department of Engineering, Faculty of Agriculture, Dalhousie University, PO Box 550, Truro, NS B2N 5E3, Canada
| | - Naseer Hussain
- Department of Natural Resource Sciences, McGill University, Macdonald Campus, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, QC H9X 3V9, Canada
| | - Joann K Whalen
- Department of Natural Resource Sciences, McGill University, Macdonald Campus, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, QC H9X 3V9, Canada
| | - O Grant Clark
- Department of Bioresource Engineering, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada.
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16
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Huang J, Liu C, Price GW, Li Y, Wang Y. Identification of a novel heavy metal resistant Ralstonia strain and its growth response to cadmium exposure. J Hazard Mater 2021; 416:125942. [PMID: 34492869 DOI: 10.1016/j.jhazmat.2021.125942] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/02/2021] [Accepted: 04/19/2021] [Indexed: 06/13/2023]
Abstract
A novel Ralstonia Bcul-1 strain was isolated from soil samples that was closest to Ralstonia pickettii. Broad-spectrum resistance was identified to a group of heavy metal ions and tolerance to concentrations of Cd2+ up to 400 mg L-1. Low concentrations of heavy metal ions did not have distinctive impact on heavy metal resistance genes and appeared to induce greater expression. Under exposure to Cd2+, cell wall components were significantly enhanced, and some proteins were also simultaneously expressed allowing the bacteria to adapt to the high Cd2+ living environment. The maximum removal rate of Cd2+ by the Ralstonia Bcul-1 strain was 78.97% in the culture medium supplemented with 100 mg L-1 Cd2+. Ralstonia Bcul-1 was able to survive and grow in a low nutrient and cadmium contaminated (0.42 mg kg-1) vegetable soil, and the cadmium removal rate was up to 65.76% in 9th growth. Ralstonia Bcul-1 mixed with biochar could maintain sustainable growth of this strain in the soil up to 75 d and the adsorption efficiency of cadmium increased by 16.23-40.80% as compared to biochar application alone. Results from this work suggests that Ralstonia Bcul-1 is an ideal candidate for bioremediation of nutrient deficient heavy metal contaminated soil.
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Affiliation(s)
- Jiaqing Huang
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences (FAAS), Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - Cenwei Liu
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences (FAAS), Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - G W Price
- Department of Engineering, Dalhousie University, Truro, NS B2N 5E3, Canada
| | - Yanchun Li
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences (FAAS), Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China
| | - Yixiang Wang
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences (FAAS), Fuzhou 350013, China; Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou 350013, China.
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17
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Shu W, Price GW, Jamieson R, Lake C. Biodegradation kinetics of individual and mixture non-steroidal anti-inflammatory drugs in an agricultural soil receiving alkaline treated biosolids. Sci Total Environ 2021; 755:142520. [PMID: 33032129 DOI: 10.1016/j.scitotenv.2020.142520] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/18/2020] [Accepted: 09/18/2020] [Indexed: 06/11/2023]
Abstract
Land application of biosolids is one potential source of pharmaceuticals and personal care products (PPCPs) into agricultural soils. Degradation is an important natural attenuation pathway that affects the fate and transport of PPCPs in the soil system and biosolids application could alter the process. The present study assessed the effect of individual and mixture compound environments on the biodegradation rate and half-life of three non-steroidal anti-inflammatory drugs (NSAIDs), naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF), in a loamy sand textured agricultural soil receiving an alkaline treated biosolid (ATB) amendment. A prolonged half-life of the target NSAIDs was determined for sterile soils and shorter half-lives in unsterile soils, indicating the loss of target compounds in all treatments was mainly attributed to biodegradation and followed first-order kinetics. IBF and NPX showed low to moderate persistence in soil and ATB amended soil, with half-lives ranging from 4.9 to 14.8 days, while KTF appeared to be highly persistent with an average half-life of 33 days. The order in which the target NSAIDs disappeared in both soil and ATB amended soil was: IBF > NPX > KTF, for both individual and mixture compound treatments. Soils that received the ATB amendment demonstrated inhibited degradation of NPX in all treatments, as well as IBF and KTF in individual compound treatment over the 14-day incubation study. We also observed an inhibition effect from the ATB amendment in sterile soil treatments. In mixture compound treatments, IBF degradation was inhibited in both soil and ATB amended soil. The degradation rate of KTF in mixture compound environment in soil was lower, while the opposite effects were observed in ATB amended soils. For NPX, the degradation was enhanced in mixture compound environment in ATB amended soil, while the same degradation rate of NPX was calculated in soil.
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Affiliation(s)
- W Shu
- Department of Process Engineering and Applied Science, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - G W Price
- Department of Engineering, Dalhousie University Faculty of Agriculture, PO Box 550, Truro, NS B2N 5E3, Canada.
| | - R Jamieson
- Department of Civil and Resource Engineering, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - C Lake
- Department of Civil and Resource Engineering, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
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18
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Price GW, Langille MGI, Yurgel SN. Microbial co-occurrence network analysis of soils receiving short- and long-term applications of alkaline treated biosolids. Sci Total Environ 2021; 751:141687. [PMID: 32889459 DOI: 10.1016/j.scitotenv.2020.141687] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 07/26/2020] [Accepted: 08/11/2020] [Indexed: 06/11/2023]
Abstract
Agricultural soils are inherently disturbed systems where organic matter additions are considered to enhance microbial community structure and resilience. High-throughput sequencing of community was applied to soils receiving annual applications of an alkaline stabilized biosolid (ATB), at four increasing rates over 10 years, as an environmental stressor in contrast to a one-time application of ATB ten years prior. Bacterial community structure was more greatly influenced by annual ATB applications relative to fungi and eukaryotes. Specifically, higher relative abundances of Proteobacteria, Acidobacteria, Bacteroidetes, and Chloroflexi were measured in annual ATB rates relative to the single ATB rates and the control. High rates of annual ATB applications resulted in lower bacterial alpha-diversity, as well as fungal and eukaryotic Shannon diversity, but single ATB or lower rates of ATB applied annually showed increased alpha -diversity relative to the control. Soil microbiome responses to annual ATB and single ATB rates were also examined using co-occurrence network analysis. High rates and frequency of ATB application resulted in a decrease in network interactions, lower average number of neighbors, and reduced network density compared to control soils. A concomitant increase in network diameter and characteristic path length further suggests annual additions of ATB led to a more adapted, but less cooperative, state in the microbiome. The data suggest a more universal functional response of microbiomes to the stressors compared to community structure and local diversity. In particular, beta-analysis and network analysis were both able to resolve significant effects on soil microbiomes 10 years post-application of low rates of ATB. Community complexity and stability were increased by single low rate of ATB additions and decreased by single high rate and annual moderate rates of ATB additions. These results provide insights into the effects that ATB additions have on soil community after only one-time use and after annual additions over a decade.
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Affiliation(s)
- G W Price
- Department of Engineering, Dalhousie University, Truro, NS, Canada
| | - Morgan G I Langille
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada; Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Svetlana N Yurgel
- Department of Plant, Food, and Environmental Sciences, Dalhousie University, Truro, NS, Canada.
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Liu C, Ye J, Lin Y, Wu J, Price GW, Burton D, Wang Y. Removal of Cadmium (II) using water hyacinth (Eichhornia crassipes) biochar alginate beads in aqueous solutions. Environ Pollut 2020; 264:114785. [PMID: 32559880 DOI: 10.1016/j.envpol.2020.114785] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 04/21/2020] [Accepted: 05/08/2020] [Indexed: 05/28/2023]
Abstract
Biochar produced from water hyacinths (Eichhornia crassipes) has been demonstrated to be an effective adsorbent for the removal of certain heavy metals and as a means of control for this highly invasive species. This study involved examined the Cd2+ sorption dynamics of an alginate encapsulated water hyacinth biochar (BAC) generated at different temperatures and modified using ferric/ferrous sulfate (MBAC). The maximum Cd2+ sorption occurred at a pH of 6 and at a solution temperature of 37 °C. Sorption equilibria for the biochar-alginate capsule (BAC) and modified biochar-alginate capsule (MBAC) treatments fit both the Langmuir (R2 = 0.876 to 0.99) and Freundlich (R2 = 0.849 to 0.971) equations. Langmuir isotherms had a better fit than the Freundlich isotherms, with maximum sorption capacities ranging from 24.2 to 45.8 mg Cd2+ g-1. Larger KL values in Freundlich modeling suggest strong bonding of the BAC and MBAC sorbents to Cd2+, with values of KL in the MBAC treatments ranging between 31 and 178% greater than the BAC treatments. Cd2+ sorption followed pseudo first-order kinetics (R2 = 0.926 to 0.991) with greater efficiency of removal using treatments with biochar generated at temperatures >500 °C. Results from this study highlight the potential for biochar-alginate capsules derived from water hyacinth to be effective for the removal of Cd2+ from wastewaters.
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Affiliation(s)
- Cenwei Liu
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, 350003, China; Fujian Key Laboratory of Agricultural Ecological Process in Red Soil Hilly Region, Fuzhou, Fujian, 350003, China
| | - Jing Ye
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, 350003, China; Fujian Key Laboratory of Agricultural Ecological Process in Red Soil Hilly Region, Fuzhou, Fujian, 350003, China
| | - Yi Lin
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, 350003, China; Fujian Key Laboratory of Agricultural Ecological Process in Red Soil Hilly Region, Fuzhou, Fujian, 350003, China
| | - Jian Wu
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, 350003, China
| | - G W Price
- Department of Engineering, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | - D Burton
- Department of Plant, Food, and Environmental Sciences, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | - Yixiang Wang
- Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, 350003, China; Fujian Key Laboratory of Agricultural Ecological Process in Red Soil Hilly Region, Fuzhou, Fujian, 350003, China.
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20
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Zhang H, Voroney RP, Price GW. Effects of Temperature and Activation on Biochar Chemical Properties and Their Impact on Ammonium, Nitrate, and Phosphate Sorption. J Environ Qual 2017; 46:889-896. [PMID: 28783786 DOI: 10.2134/jeq2017.02.0043] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
There have been limited studies of how pyrolysis temperature and activation processes alter the chemical properties of biochar and how these changes influence ammonium (NH), nitrate (NO), and phosphate (PO) sorption. This study compared the chemical properties of biochars and activated biochars (ActBC with steam and CO activation) produced by slow pyrolysis at 200 (BC200), 400 (BC400), 600 (BC600), 800 (ActBC200, ActBC400, ActBC600), and 850°C (sulfachar-S enriched biochar with steam activation). Quantitative solid-state C nuclear magnetic resonance spectroscopy and elemental analysis were used to study temperature and activation on biochar chemical properties. The sorption capacity of biochars for NH, NO, and PO were measured by batch sorption experiments. Nuclear magnetic resonance spectroscopy data showed that BC200 contained mainly aliphatic C compounds (86% of O-alkyl) belonging to cellulose and hemicellulose, whereas BC400 and BC600 composition was dominated by fused aromatic C structures, containing 81 and 97% aromatic C, respectively. Increasing pyrolysis temperatures decreased biochar total C but increased its cation exchange capacity, pH, and contents of total N and P, calcium, potassium, and magnesium. The BC200 released NO and PO, whereas sulfachar and ActBC200 sorbed significantly higher amounts NO and PO than BC600 by 83 and 96%, respectively, across aqueous solutions. Sulfachar and BC400 sorbed significantly greater amounts NH than did the other biochars. This study shows that production temperature significantly affects biochar chemical properties and that activation increases NO and PO sorption. These results suggest that activated biochar could be useful for sorbing soil N and P, thereby reducing leaching losses.
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Zhang Y, Price GW, Jamieson R, Burton D, Khosravi K. Sorption and desorption of selected non-steroidal anti-inflammatory drugs in an agricultural loam-textured soil. Chemosphere 2017; 174:628-637. [PMID: 28199939 DOI: 10.1016/j.chemosphere.2017.02.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/31/2017] [Accepted: 02/04/2017] [Indexed: 05/12/2023]
Abstract
Non-steroidal, anti-inflammatory drugs (NSAIDs) are widely used pharmaceutical products with analgesic and anti-inflammatory effects that are consistently detected in municipal wastewater systems and in municipal biosolids. Land application of biosolids and irrigation with reclaimed wastewater introduces these compounds into agricultural environments, which is an emerging issue of concern for ecosystem health. In this study, the sorption-desorption behaviour of four commonly consumed NSAIDs, including naproxen (NPX), ibuprofen (IBU), ketoprofen (KTF), and diclofenac (DCF), was examined in a loam textured soil exposed to either an individual-compound or a mixture of the four NSAIDs. The proportion of NSAIDs adsorbed to the soil in the mixture-compound system was 72%, 55%, 50% and 45%, for diclofenac, naproxen, ketoprofen, and ibuprofen, respectively, and differed slightly from the individual compound adsorption. Diclofenac displayed strong sorption and low desorption in both the individual-compound and mixture-compound systems. Naproxen and ibuprofen exhibited significant differences between the adsorption isotherms of the individual-compound and mixture-compound systems. Results of this study highlight differences in the sorption behaviour of NSAIDs, when present as mixtures, possibly through multilayer bonding effects or complexation with cationic metals or organo-clays from the soil. Soil organic matter (SOM) may have played a role in determining some of the interactions between the compounds but other factors associated with the mixture-compound system, such as cation bridging or multilayer cooperative adsorption. Desorption data suggests that the mechanisms involved in binding NSAIDs to the soil surface are also influence by the presence of other compounds in a mixture. A reduction in desorption was observed for all four NSAIDs in the mixture-compound system relative to the individual-compound system, but were greatest for naproxen and ibuprofen. The sorption-desorption hysteresis increased for naproxen and ibuprofen in the mixture-compound system. This study suggests that cooperative adsorption plays a role in the interaction of NSAIDs when present as mixtures rather than as individual compounds.
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Affiliation(s)
- Y Zhang
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | - G W Price
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada.
| | - R Jamieson
- Department of Civil and Resource Engineering, Faculty of Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - D Burton
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | - K Khosravi
- Centre for Built Environment, Faculty of Applied Science and Engineering Technology, Seneca College, Toronto, Ontario, Canada
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Sayyad G, Price GW, Sharifi M, Khosravi K. Fate and transport modeling of phthalate esters from biosolid amended soil under corn cultivation. J Hazard Mater 2017; 323:264-273. [PMID: 27453260 DOI: 10.1016/j.jhazmat.2016.07.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 07/10/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
Phthalate esters (PAEs) are prevalent in the environment due to the broad range of industrial, agriculture and domestic applications. The ubiquitous use of PAEs has resulted in their potential to reach groundwater sources through application of agri-chemicals and municipal biosolids. A study was conducted to monitor the fate and transport of seven commonly detected PAEs in the environment including: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), bis(di-ethyl hexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), dipentyl phthalate (DPP), and di-n-butyl phthalate (DnBP). Biosolids sourced from the Halifax Regional Municipality were applied at three rates on field-based lysimeter cells which were cropped to corn (Zea mays) for one growing season. In the present study, breakthrough curves (BTCs) were established for phthalates leaching from a corn-cultivated agricultural soil profile. The HYDRUS-1D model and a two-site sorption model were applied to predict transport parameters of PAEs using an inverse solution approach. Results of our research revealed that higher PAE adsorption was observed based on increasing carbon chain number. In addition, higher values of F (i.e. the fraction of type-1 sorption sites assumed to be in equilibrium with the solution phase) and lower values of D (i.e. dispersion coefficient) were observed for PAEs with large carbon chains which was validated both through the empirical dataset and the model simulations.
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Affiliation(s)
- G Sayyad
- Department of Soil Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran; Environmental & Life Sciences, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9J 7B8, Canada
| | - G W Price
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia B2N 5E3, Canada.
| | - M Sharifi
- Canada Research Chair, Trent School of Environment, Peterborough, Ontario K9J 7B8, Canada
| | - K Khosravi
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia B2N 5E3, Canada
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Gillis JD, Price GW, Prasher S. Lethal and sub-lethal effects of triclosan toxicity to the earthworm Eisenia fetida assessed through GC-MS metabolomics. J Hazard Mater 2017; 323:203-211. [PMID: 27468629 DOI: 10.1016/j.jhazmat.2016.07.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 07/06/2016] [Accepted: 07/07/2016] [Indexed: 06/06/2023]
Abstract
Triclosan (TCS) is a ubiquitous contaminant in municipal biosolids, which has also been detected in soils and earthworms sampled from agricultural fields amended with biosolids. The goal of this study was to evaluate the toxicity of TCS to earthworms using a metabolomics-based approach for an improved interpretation of toxicity. Toxicity of TCS was assessed using the OECD Method 207 filter paper contact test measuring the endpoints of weight loss, mortality, and ten metabolites determined by GC-MS. Eight earthworms were exposed as individual replicates to six concentrations of triclosan (0, 0.0001, 0.001, 0.01, 0.1, and 1mg TCS cm-2) on filter paper, with mortality assessed after 6, 24 and 48h. Mortalities were first observed at 24h, with 100% mortality in the 1 and 0.1mgcm-2 treatments. Worms at 1mgcm-2 lost most of their coelomic fluid before they could be sampled. The 48h LC50 for triclosan was estimated to be 0.006 and 0.008mgcm-2 by a linear and logistic model, respectively. Based on the LC50, triclosan is relatively more toxic to earthworms than a number of other emerging contaminants, but is less toxic than other chlorophenols and many pesticides. Alanine, valine, leucine, serine, phenylalanine, putrescine, spermidine, mannitol, and inositol were significantly different between treatments, although changes were most often associated with mortality rather than triclosan exposure. An increase in putrescine and decrease in amino acids, polyols, and spermidine were associated with mortality, suggesting decomposition had begun. Principal components analysis did not reveal evidence of metabolic impacts at sub-lethal concentrations. However, there were changes in the pattern of correlations between metabolite pairs in surviving worms at both 0.0001 and 0.001mgcm-2 exposure compared to the control.
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Affiliation(s)
- J Daniel Gillis
- Department of Bioresource Engineering, McGill University, Faculty of Agricultural and Environmental Sciences, Macdonald-Stewart Building MS1-027, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, Quebec, H9X 3V9, Canada.
| | - Gordon W Price
- Department of Engineering, Dalhousie University, Faculty of Agriculture, 39 Cox Road, PO Box 550, Truro, Nova Scotia, B2N 5E3, Canada
| | - Shiv Prasher
- Department of Bioresource Engineering, McGill University, Faculty of Agricultural and Environmental Sciences, Macdonald-Stewart Building MS1-027, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, Quebec, H9X 3V9, Canada
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Hurtado C, Cañameras N, Domínguez C, Price GW, Comas J, Bayona JM. Effect of soil biochar concentration on the mitigation of emerging organic contaminant uptake in lettuce. J Hazard Mater 2017; 323:386-393. [PMID: 27143287 DOI: 10.1016/j.jhazmat.2016.04.046] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 04/14/2016] [Accepted: 04/18/2016] [Indexed: 06/05/2023]
Abstract
Although crop uptake of emerging organic contaminants (EOC) from irrigation water and soils has been previously reported, successful mitigation strategies have not yet been established. In this study, soil was amended with a wood-based biochar (BC) at two rates (0, 2.5 and 5% w/w) to evaluate the effect on mitigation of EOC uptake (i.e. bisphenol A, caffeine, carbamazepine, clofibric acid, furosemide, ibuprofen, methyl dihydrojasmonate, tris(2-chloroethyl)phosphate, triclosan, and tonalide) in lettuce (Lactuca sativa L.). After 28 days of irrigation with water containing EOCs at 15μgL-1, the average EOC concentration in roots and leaves decreased by 20-76% in biochar amended soil relative to non BC-amended soil. In addition, the enantiomeric fractions (EF) of ibuprofen (IBU) in biochar amended soils (EF=0.58) and unamended soils (EF=0.76) suggest that the IBU sorbed fraction in BC is more recalcitrant to its biodegradation.
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Affiliation(s)
- Carlos Hurtado
- Environmental Chemistry Department, IDAEA-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain
| | - Núria Cañameras
- Department of Agri-Food Engineering and Biotechnology DEAB-UPC, Esteve Terrades 8, Building 4, E-08860 Castelldefels, Spain
| | - Carmen Domínguez
- Environmental Chemistry Department, IDAEA-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain
| | - Gordon W Price
- Environmental Chemistry Department, IDAEA-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain; Department of Engineering, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Bible Hill, Nova Scotia, Canada
| | - Jordi Comas
- Department of Agri-Food Engineering and Biotechnology DEAB-UPC, Esteve Terrades 8, Building 4, E-08860 Castelldefels, Spain
| | - Josep M Bayona
- Environmental Chemistry Department, IDAEA-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain.
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Khosravi K, Price GW. Determination of phthalates in soils and biosolids using accelerated solvent extraction coupled with SPE cleanup and GC–MS quantification. Microchem J 2015. [DOI: 10.1016/j.microc.2015.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
Environmental benefits reported in the literature of using biochar as a soil amendment are generally increased microbial activity and reduced greenhouse gas (GHG) emissions. This study determined the effects of amendment with biomass feedstocks (spent coffee grounds, wood pellets, and horse bedding compost) and that of biochars (700°C) produced from these feedstocks on soil microbial biomass (C and N) and activity. Soils were amended with these substrates at 0.75% by weight and incubated for up to 175 d under laboratory conditions. Biochar residual effects on soil microbial activity were also studied by amending these soils with either ammonium nitrate (NHNO, 35 mg N kg) or with glucose (864 mg C kg) plus NHNO. Soil microbial biomass C and N, net N mineralization, and CO, NO, and CH emissions were measured. Amendment with biomass feedstocks significantly increased soil microbial biomass and activity, whereas amendment with the biochars had no significant effect. Also, biochar amendment had no significant effect on either net N mineralization or NO and CH emissions from soil. These results indicate that production of biochars at this high temperature eliminated potential substrates. Microbial biomass C in biochar-amended and unamended soils was not significantly different following additions of NHNO or glucose plus NHNO, suggesting that microbial access to otherwise labile C and N was not affected. This study shows that biochars produced at 700°C, regardless of feedstock source, do not enhance soil microbial biomass or activity.
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Hussain I, Price GW, Farid AH. Inactivation of Aleutian mink disease virus through high temperature exposure in vitro and under field-based composting conditions. Vet Microbiol 2014; 173:50-8. [PMID: 25139658 DOI: 10.1016/j.vetmic.2014.07.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/15/2014] [Accepted: 07/16/2014] [Indexed: 10/25/2022]
Abstract
Disposal of manure contaminated with Aleutian mink disease virus (AMDV) is a significant concern to the mink industry. Inactivation of AMDV under field conditions has received limited attention in the scientific literature. We evaluated the thermal inactivation of AMDV in vitro and during composting of mink manure. Spleen homogenate containing AMDV was heated under controlled conditions at 45°C, 55°C, and 65°C for 3 days. Results of the in vitro study identified complete absence of viral replication in mink at 65°C only. Next, manure-mixed AMDV packed in polyester pouches was inserted in different layers of three replicate mink manure compost piles. The virus was retrieved after the compost piles had undergone a heating period and subsequently returned to ambient temperatures. Temperature regimes in the compost piles were categorized as ≥65°C, ≥60-64°C, and ≥55-59°C. Initially, layer-wise composite virus samples were assayed for virus replication in mink. Twenty-one-day post-inoculation (p.i.) plasma tested for AMDV and antibodies indicated infection in 40%, 80%, and 100% of mink inoculated from samples originating from the top, center and bottom layers of the piles, respectively. Subsequently, the virus was extracted from individual pouches in compost layers achieving thermal activity ≥65°C and was tested in mink. No antibodies or virus was detected in plasma taken weekly up to day 21 p.i. PCR data of bone marrow and lymph nodes collected on day 21 p.i. also showed no AMDV. However, mink that received virus from positive control manure indicated infection in their plasma as early as 1 week p.i.
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Affiliation(s)
- I Hussain
- Department of Plant and Animal Sciences, Dalhousie University, Faculty of Agriculture, Truro, Nova Scotia, Canada B2N 5E3
| | - G W Price
- Department of Engineering, Dalhousie University, Faculty of Agriculture, Truro, Nova Scotia, Canada B2N 5E3.
| | - A H Farid
- Department of Plant and Animal Sciences, Dalhousie University, Faculty of Agriculture, Truro, Nova Scotia, Canada B2N 5E3
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Price GW, Zeng J, Arnold P. Influence of agricultural wastes and a finished compost on the decomposition of slaughterhouse waste composts. J Environ Manage 2013; 130:248-254. [PMID: 24095787 DOI: 10.1016/j.jenvman.2013.08.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/16/2013] [Accepted: 08/24/2013] [Indexed: 06/02/2023]
Abstract
The objective of this study was to evaluate the efficacy of combining agricultural wastes or a finished compost (wheat straw, horse manure and bedding, sheep manure, and a wheat straw-SHW finished compost) as compost feedstocks with cattle slaughterhouse wastes (SHW) on a field-scale. The composts were managed in covered bins over 200 days and physico-chemical parameters related to organic matter bio-degradation were measured over time. Thermophilic temperatures were maintained above 55 °C for 12-46 days to meet the Canadian Council of Ministers of the Environment (CCME) guidelines for pathogen control. Final C:N ratios were highest in a horse manure and bedding:SHW compost at 23:1 but ranged from 18.5 to 20.5:1 for the remaining three treatments, representing a wheat straw:SHW compost and different combinations of horse manure and bedding, SHW, and/or sheep manure. Average reduction in mass of total carbon across all the composts in the current study was 54.2%. Maturity tests at the end of the study determined that the CO2-C evolution rate in all compost products was less than 1 mg g(-1) organic matter day(-1) suggesting highly stable final compost products. Compost mass reductions all responded as exponential decay functions with R(2) values ranging from 0.84 to 0.99 regardless of compost feedstock composition. Agricultural by-products and composts are suitable feedstocks for use with SHW to generate a stable final product while meeting regulatory parameters to achieve conventional pathogen control.
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Affiliation(s)
- G W Price
- PO Box 550, Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada B2N 5E3.
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Zeng J, Price GW, Arnold P. Evaluation of an aerobic composting process for the management of Specified Risk Materials (SRM). J Hazard Mater 2012; 219-220:260-266. [PMID: 22525479 DOI: 10.1016/j.jhazmat.2012.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 03/14/2012] [Accepted: 04/02/2012] [Indexed: 05/31/2023]
Abstract
In Nova Scotia (NS), approximately 2700 tonnes of Specified Risk Materials (SRM) are produced annually. SRM disposal is a serious concern for abattoirs and the beef industry. Composting offers a low risk and simple means to transform raw SRM into a more stable and easily managed material. In this project, wheat straw and sawdust were used to compost with SRM on a pilot scale. The study evaluated changes over time in total carbon, total nitrogen, pH, temperature, moisture content and electrical conductivity. Compost temperatures in all treatments met the Canadian Council of Ministers of the Environment (CCME) guidelines for pathogen kill. The compost maturity tests showed that the evolution of CO(2)-C in all the final compost products was less than 1 mg g(-1) organic matter day(-1). Wheat straw performed well as a composting feedstock for raw SRM as sawdust. While the wheat straw has advantages including greater availability, lower cost and easily decomposable carbon compounds more management is required to maintain adequate compost temperatures. The influences of seasonal variations due to temperate climatic conditions on SRM composting were also studied with wheat straw. The results suggest no significant differences in composting effectiveness between the two seasons.
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Affiliation(s)
- J Zeng
- Department of Engineering, Nova Scotia Agricultural College, Truro, Nova Scotia, Canada
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Liu K, Price GW. Evaluation of three composting systems for the management of spent coffee grounds. Bioresour Technol 2011; 102:7966-7974. [PMID: 21704514 DOI: 10.1016/j.biortech.2011.05.073] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Revised: 05/05/2011] [Accepted: 05/25/2011] [Indexed: 05/31/2023]
Abstract
This study was conducted to evaluate the optimum composting approach for the management of spent coffee grounds from the restaurant and ready-to-serve coffee industry. Three composting systems were assessed, including in-vessel composting, vermicomposting bins, and aerated static pile bin composting, over study periods ranging from 47 to 98 days. Total carbon content was reduced by 5-7% in the spent coffee ground treatments across the three composting systems. Nitrogen and other mineral nutrient contents were conserved or enhanced from the initial to the final composts in all the composting systems assessed. Earthworm growth and survival (15-80%) was reduced in all the treatments but mortality rates were lower in coffee treatments with cardboard additions. A decline in earthworm mortality with cardboard additions was the result of reduced exposure to organic compounds and chemicals released through the decomposition of spent coffee grounds.
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Affiliation(s)
- K Liu
- Department of Engineering, Nova Scotia Agricultural College, Truro, Nova Scotia, P.O. Box 550, Canada B2N 5E3
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Abstract
Previous findings on electrophysiological features related to depression predict that these correlate with clinical assessment, and potentially act as proxy measures of state changes. We investigated selected electrophysiological features to evaluate their utility as proxies for clinical ratings and in prediction of treatment outcome. Using typical EEG data from an repetitive transcranial magnetic stimulation (rTMS) treatment regime, we analyzed individual alpha power and frequency, and asymmetry index from 39 patients with treatment resistant depression. The prognostic utility of these features was assessed in terms of group identification, correlation with clinical rating, or association with the time course of treatment. There was no significant group difference in asymmetry between depression patients and normal and clinical controls. Background alpha was significantly less in depression patients than controls, with the schizophrenia group midway between. There was no significant group change in asymmetry index or background alpha activity with treatment. There was a weak effect of rTMS over each session on alpha power and on asymmetry, but in the opposite direction to predictions. There was weak evidence of predicted correlation between asymmetry index change and clinical rating change, as well as in final scores that was opposite to predictions. Finally there was no strong evidence that either feature fitted a linear or more complex model of daily treatment. In conclusion, the findings are not sufficient, under our current clinical treatment regime, to support the use of background alpha activity or frontal asymmetry as proxies for clinical assessment. Several findings, however, provide support for further research in this direction.
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Affiliation(s)
- G W Price
- Clinical Research and Neurophysiology, North Metropolitan Area Health Service-Mental Health, Perth, Australia.
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Abstract
Papermill biosolids (PB) can provide multiple benefits to the soil system. The purpose of this study was to quantify the effects of a high C/N ratio (C/N = 100) de-inked PB on soil physical and chemical properties, including soil bulk density, infiltration rates, wet aggregate stability, total soil carbon, and heavy metal concentrations. Four rates of PB (0, 50, 100, and 150 Mg ha(-1)) were applied annually, for up to 3 yr, on four agricultural soils in Ontario, Canada. Decreases in soil bulk density between 0.27 and 0.35 g cm(-3), relative to the nonamended treatment, were observed in soils receiving PB treatments over 3 yr. Total soil carbon increased within 1 yr on PB-amended soils planted to soybeans but not on soils planted to corn. Hydraulic conductivities (K fs) were greater in all soils receiving PB amendments relative to the nonamended treatment throughout the study. Other properties measured, such as pH and electrical conductivity, were relatively unchanged after 2 yr of PB applications. While some increases in heavy metal accumulation occurred, there were no clear trends observed at any of the sites related to PB rates. The results of this study provide support to the idea that annual applications of PB can add significantly to the stability of soil structure.
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Affiliation(s)
- G W Price
- Dep. of Land Resource Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
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Thomas DR, Atkinson PJ, Hastie PG, Roberts JC, Middlemiss DN, Price GW. [3H]-SB-269970 radiolabels 5-HT7 receptors in rodent, pig and primate brain tissues. Neuropharmacology 2002; 42:74-81. [PMID: 11750917 DOI: 10.1016/s0028-3908(01)00151-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The selective 5-HT7 receptor antagonist radioligand, [3H]-SB-269970, has been reported to radiolabel the human cloned 5-HT7(a) receptor and 5-HT7 receptors in guinea pig cortex (thomas et al, 2000). Saturation analysis of [3H]-SB-269970 binding to mouse forebrain, rat cortex, pig cortex, marmoset cortex and human thalamus membranes was consistent with labelling a homogenous population of binding sites in each tissue. K(D) values for [3H]-SB-269970 binding in these tissues ranged from 0.9 to 2.3 nM, being similar to those reported for the human cloned and guinea pig cortex 5-HT7 receptors (1.3 and 1.7 nM, respectively). Bmax values for [3H]-SB-269970 binding to the mouse, rat, pig, marmoset and human brain membranes were 20, 30, 31, 14 and 68 fmoles x mg x protein(-1), respectively. For each species the profile of inhibition of [3H]-SB-269970 binding, using a number of 5-HT7 receptor agonists and antagonists, correlated well with that reported for the human cloned 5-HT7(a) receptor (correlation coefficients were 0.95, 0.94, 0.92, 0.95, 0.97 versus the mouse, rat, pig, marmoset and human tissues, respectively). In conclusion, [3H]-SB-269970 has been shown to radiolabel 5-HT7 receptors in rodent, pig and primate brain and represents a valuable tool with which to further characterise the distribution and function of 5-HT7 receptors in native tissues and elucidate their potential role in disease states.
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Affiliation(s)
- D R Thomas
- GlaxoSmithKline Pharmaceuticals, Psychiatry Centre of Excellence for Drug Discovery, New Frontiers Science Park (North), Third Avenue, CM19 5AW, Harlow, Essex, UK.
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Abstract
5-HT1B autoreceptors are involved in the control of extracellular 5-HT levels from both the terminal and cell body regions of serotonergic neurons. In this manuscript we review the pharmacological and pharmacokinetic data available for the selective and potent 5-HT1B receptor inverse agonist, SB-236057-A (1'-ethyl-5-(2'-methyl-4'-(5-methyl-1,3,4-oxadiazolyl-2-yl)biphenyl-4-carbonyl)-2,3,6,7-tetrahydrospiro (furo[2,3-f]indole-3,4'-piperidine) hydrochloride). SB 236057-A has been shown to have high affinity for human 5-HT1B receptors (pK(i) = 8.2) and displays 80 or more fold selectivity for the human 5-HT1B receptor over other 5-HT receptors and a range of additional receptors, ion channels and enzymes. In functional studies at human 5-HT1B receptors SB-236057-A displayed inverse agonism (pA(2) = 8.9) using [(35)S]GTPgammaS binding, and silent antagonism (pA(2) = 9.2) using cAMP accumulation. SB-236057-A also acted as an antagonist at the 5-HT terminal autoreceptor as measured by [3H]5-HT release from electrically stimulated guinea pig and human cortical slices. In the guinea pig, pharmacokinetic analysis demonstrated that SB-236057-A was bioavailable and according to in vivo pharmacodynamic assays it enters brain and has a long duration of action. Importantly no side effect liability was evident at relevant doses from anxiogenic, cardiovascular, sedative or migraine viewpoints. In vivo microdialysis studies demonstrated that SB-236057-A is an antagonist in the guinea pig cortex but has no effect on extracellular 5-HT levels per se. In contrast, SB-236057-A increased extracellular 5-HT levels in the guinea pig dentate gyrus. This increase in 5-HT release was comparable to that observed after 14 days of paroxetine administration. SB-236057-A has been a useful tool in confirming that, in either guinea pigs or humans, the terminal 5-HT autoreceptor is of the 5-HT1B subtype. It appears that acute 5-HT1B receptor blockade, by virtue of increased 5-HT release in the dentate gyrus, may provide a rapidly acting antidepressant.
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Affiliation(s)
- C Roberts
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Third Ave., Harlow, Essex, CM19 5AW, UK.
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Abstract
The existence of multiple 5-HT autoreceptors in the central nervous system is now firmly established and they have been pharmacologically identified as belonging to the 5-HT(1A), 5-HT(1B), and 5-HT(1D) receptor subtypes. In addition, 5-HT(1F), 5-HT(5A), and 5-HT(7) receptors remain as potential candidates for additional autoreceptors. The emergence of selective ligands, such as SB-224289 (5-HT(1B) receptor antagonist), BRL 15572 (5-HT(1D) receptor antagonist), GR 127935 (a mixed 5-HT(1B/1D) receptor antagonist), LY 334370 (5-HT(1F) receptor agonist), and SB-269970 (5-HT(7) receptor antagonist), has aided the characterisation of 5-HT autoreceptors and has highlighted the complexity of mechanisms which modulate the release of 5-HT.
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Affiliation(s)
- C Roberts
- Neuroscience Research, GlaxoSmithKline, Harlow, Essex, UK.
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Watson J, Roberts C, Scott C, Kendall I, Collin L, Day NC, Harries MH, Soffin E, Davies CH, Randall AD, Heightman T, Gaster L, Wyman P, Parker C, Price GW, Middlemiss DN. SB-272183, a selective 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptor antagonist in native tissue. Br J Pharmacol 2001; 133:797-806. [PMID: 11454652 PMCID: PMC1572841 DOI: 10.1038/sj.bjp.0704133] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2001] [Revised: 04/27/2001] [Accepted: 04/27/2001] [Indexed: 11/08/2022] Open
Abstract
A novel compound, SB-272183 (5-Chloro-2, 3-dihydro-6-[4-methylpiperazin-1-yl]-1[4-pyridin-4-yl]napth-1-ylaminocarbonyl]-1H-indole), has been shown to have high affinity for human 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptors with pK(i) values of 8.0, 8.1 and 8.7 respectively and is at least 30 fold selective over a range of other receptors. [(35)S]-GTPgammaS binding studies showed that SB-272183 acts as a partial agonist at human recombinant 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptors with intrinsic activities of 0.4, 0.4 and 0.8 respectively, compared to 5-HT. SB-272183 inhibited 5-HT-induced stimulation of [(35)S]-GTPgammaS binding at human 5-HT(1A) and 5-HT(1B) receptors to give pA(2) values of 8.2 and 8.5 respectively. However, from [(35)S]-GTPgammaS autoradiographic studies in rat and human dorsal raphe nucleus, SB-272183 did not display intrinsic activity up to 10 microM but did block 5-HT-induced stimulation of [(35)S]-GTPgammaS binding. From electrophysiological studies in rat raphe slices in vitro, SB-272183 did not effect cell firing rate up to 1 microM but was able to attenuate (+)8-OH-DPAT-induced inhibition of cell firing to give an apparent pK(b) of 7.1. SB-272183 potentiated electrically-stimulated [(3)H]-5-HT release from rat and guinea-pig cortical slices at 100 and 1000 nM, similar to results previously obtained with the 5-HT(1B) and 5-HT(1D) receptor antagonist, GR127935. Fast cyclic voltammetry studies in rat dorsal raphe nucleus showed that SB-272183 could block sumatriptan-induced inhibition of 5-HT efflux, with an apparent pK(b) of 7.2, but did not effect basal efflux up to 1 microM. These studies show that, in vitro, SB-272183 acts as an antagonist at native tissue 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptors.
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MESH Headings
- 8-Hydroxy-2-(di-n-propylamino)tetralin/pharmacology
- Action Potentials/drug effects
- Aged
- Aged, 80 and over
- Animals
- Autoradiography
- Binding, Competitive/drug effects
- Cerebral Cortex/drug effects
- Cerebral Cortex/metabolism
- Dose-Response Relationship, Drug
- Electric Stimulation
- Female
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Guinea Pigs
- Humans
- Indoles/metabolism
- Indoles/pharmacology
- Mesencephalon/drug effects
- Mesencephalon/metabolism
- Middle Aged
- Neurons/drug effects
- Neurons/physiology
- Piperazines/metabolism
- Piperazines/pharmacology
- Pyridines/pharmacology
- Radioligand Assay
- Raphe Nuclei/cytology
- Raphe Nuclei/drug effects
- Raphe Nuclei/metabolism
- Rats
- Receptor, Serotonin, 5-HT1B
- Receptor, Serotonin, 5-HT1D
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/metabolism
- Receptors, Serotonin, 5-HT1
- Serotonin/metabolism
- Serotonin/pharmacology
- Serotonin Antagonists/metabolism
- Serotonin Antagonists/pharmacology
- Serotonin Receptor Agonists/pharmacology
- Sulfur Radioisotopes
- Tritium
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Affiliation(s)
- J Watson
- Neuroscience Research and Department of Medicinal Chemistry, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW.
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Roberts C, Allen L, Langmead CJ, Hagan JJ, Middlemiss DN, Price GW. The effect of SB-269970, a 5-HT(7) receptor antagonist, on 5-HT release from serotonergic terminals and cell bodies. Br J Pharmacol 2001; 132:1574-80. [PMID: 11264252 PMCID: PMC1572709 DOI: 10.1038/sj.bjp.0703979] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The presence of 5-HT(7) receptor mRNA and protein in 5-HT neurons suggests that this receptor may act as a 5-HT autoreceptor. In this study, the effect of the 5-HT(7) receptor antagonist, SB-269970 ((R)-1-[3-hydroxy phenyl)sulfonyl]-2-[2-(4-methyl-1-piperidinyl)ethyl]pyrrolidine), was investigated on 5-HT release in the guinea-pig and rat cortex and the rat dorsal raphe nucleus (DRN), using the techniques of in vitro [(3)H]-5-HT release or fast cyclic voltammetry, respectively. 2. Cortical slices were loaded with [(3)H]-5-HT and release was evoked by electrical stimulation. 5-CT inhibited the evoked release of [(3)H]-5-HT in a concentration-dependent manner. SB-269970 had no significant effect on [(3)H]-5-HT release while the 5-HT(1B) receptor antagonist, SB-224289 significantly potentiated [(3)H]-5-HT release. In addition, SB-269970 was unable to attenuate the 5-CT-induced inhibition of release while SB-224289 produced a rightward shift of the 5-CT response, generating estimated pK(B) values of 7.8 and 7.6 at the guinea-pig and rat terminal 5-HT autoreceptors respectively. 3. Rat DRN slices were electrically stimulated and the evoked 5-HT efflux detected by voltammetric analysis. 8-OH-DPAT inhibited evoked 5-HT efflux and was fully reversed by WAY 100635. SB-269970 had no effect on either 5-HT efflux per se or 8-OH-DPAT-induced inhibition of 5-HT efflux. In addition, 5-CT inhibited 5-HT efflux in a concentration-dependent manner. SB-269970 was unable to attenuate the 5-CT-induced inhibition of 5-HT efflux. 4. In conclusion, we were unable to provide evidence to suggest a 5-HT autoreceptor role for 5-HT(7) receptors. However, investigations with more selective 5-HT(7) receptor agonists are needed to confirm the data reported here.
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Affiliation(s)
- C Roberts
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW.
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Selkirk JV, Price GW, Nahorski SR, Challiss RA. Cell type-specific differences in the coupling of recombinant mGlu1alpha receptors to endogenous G protein sub-populations. Neuropharmacology 2001; 40:645-56. [PMID: 11311892 DOI: 10.1016/s0028-3908(00)00208-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In this study the effects of cell background on the coupling of the type 1alpha metabotropic glutamate (mGlu1alpha) receptor to different G protein sub-populations by recombinant expression of this receptor subtype in baby hamster kidney (BHK) and Chinese hamster ovary (CHO) cells have been investigated. Receptor-G protein interactions were assessed using [(35)S]GTPgammaS binding and subsequent Galpha subunit-specific immunoprecipitation. In a CHO cell line (CHO-lac-mGlu1alpha), where mGlu1alpha receptor expression is under inducible control, stimulation of membranes with the mGlu receptor agonist quisqualate resulted in an increase in specific [(35)S]GTPgammaS binding to G(q/11)alpha only, whereas in a BHK cell line (BHK-mGlu1alpha) agonist stimulation increased [(35)S]GTPgammaS binding to G(q/11)alpha and also to pertussis toxin (PTx)-sensitive G(i/o) proteins (assessed using G(i1/2)alpha- and G(i3/o)alpha-specific antibodies). These data are consistent with our previous observations of dual, antagonistic G(q/11)/G(i/o) regulation of phospholipase C (PLC) in BHK-mGlu1alpha cells, whereas no evidence was found for a G(i/o) modulation of PLC activity in the CHO-lac-mGlu1alpha cell line. PTx pre-treatment of either cell line had no effect on either the magnitude or the concentration-dependency of agonist-stimulated [(35)S]GTPgammaS-G(q/11)alpha binding, excluding the possibility that receptor-G(i/o) uncoupling can unmask an increase in receptor-G(q/11) interaction. mGlu1alpha receptor expression per se had little effect on Galpha protein expression levels in either CHO or BHK cell lines, with the possible exception of a small, but consistent increase in G(o)alpha expression in BHK-mGlu1alpha cells compared to the vector-transfected control cell line (BHK-570). Semi-quantitative assessment of mGlu1alpha receptor immunoreactivity and [(3)H]quisqualate saturation binding analysis demonstrated a ca 10-fold higher mGlu1alpha receptor content in BHK cells. Whether the higher receptor expression level in BHK-mGlu1alpha cells underlies the additional G(i/o) coupling observed in this cell line, or additional factors contribute to the phenomenon are discussed.
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Affiliation(s)
- J V Selkirk
- Department of Cell Physiology and Pharmacology, Maurice Shock Medical Sciences Building, University of Leicester, University Road, Leicester LE1 9HN, UK.
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39
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Abstract
5-HT1A, 5-HT1B and 5-HT1D receptors are known to function as 5-HT autoreceptors in the rat dorsal raphe nucleus (DRN), modulating local 5-HT efflux. However, there are no studies on the simultaneous blockade of these receptors in the DRN. We investigated the effect of 5-HT1B and 5-HT1D receptor antagonists on 5-HT efflux in rat DRN, alone and in the presence of 5-HT1A receptor antagonists, using the technique of fast cyclic voltammetry. The 5-HT1A receptor antagonist, WAY 100635, and the 5-HT1B receptor antagonist, SB-224289, had no effect on 5-HT efflux while the 5-HT1B/1D receptor antagonist, GR 127935, produced a small decrease in 5-HT efflux. In contrast, the 5-HT1D receptor antagonist, BRL 15572, produced a significant increase in 5-HT efflux. Co-perfusion of WAY 100635 and SB-224289 significantly increased 5-HT efflux. In addition, WAY 100635 reversed the small inhibition of 5-HT efflux observed with GR 127935 but had no effect on the BRL 15572-induced increase. Antagonism of all three 5-HT autoreceptors with SB-224289, BRL 15572 and WAY 100635 significantly increased 5-HT efflux. These data confirm that 5-HT efflux within the DRN is under the control of 5-HT1A, 5-HT1B and 5-HT1D autoreceptors and elevation of 5-HT efflux was greatest following antagonism of 5-HT1A and 5-HT1B receptors.
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Affiliation(s)
- C Roberts
- Department of Neuroscience Research, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Essex, CM19 5AW, Harlow, UK.
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40
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Calver AR, Robbins MJ, Cosio C, Rice SQ, Babbs AJ, Hirst WD, Boyfield I, Wood MD, Russell RB, Price GW, Couve A, Moss SJ, Pangalos MN. The C-terminal domains of the GABA(b) receptor subunits mediate intracellular trafficking but are not required for receptor signaling. J Neurosci 2001; 21:1203-10. [PMID: 11160390 PMCID: PMC6762247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
GABA(B) receptors are G-protein-coupled receptors that mediate slow synaptic inhibition in the brain and spinal cord. These receptors are heterodimers assembled from GABA(B1) and GABA(B2) subunits, neither of which is capable of producing functional GABA(B) receptors on homomeric expression. GABA(B1,) although able to bind GABA, is retained within the endoplasmic reticulum (ER) when expressed alone. In contrast, GABA(B2) is able to access the cell surface when expressed alone but does not couple efficiently to the appropriate effector systems or produce any detectable GABA-binding sites. In the present study, we have constructed chimeric and truncated GABA(B1) and GABA(B2) subunits to explore further GABA(B) receptor signaling and assembly. Removal of the entire C-terminal intracellular domain of GABA(B1) results in plasma membrane expression without the production of a functional GABA(B) receptor. However, coexpression of this truncated GABA(B1) subunit with either GABA(B2) or a truncated GABA(B2) subunit in which the C terminal has also been removed is capable of functional signaling via G-proteins. In contrast, transferring the entire C-terminal tail of GABA(B1) to GABA(B2) leads to the ER retention of the GABA(B2) subunit when expressed alone. These results indicate that the C terminal of GABA(B1) mediates the ER retention of this protein and that neither of the C-terminal tails of GABA(B1) or GABA(B2) is an absolute requirement for functional coupling of heteromeric receptors. Furthermore although GABA(B1) is capable of producing GABA-binding sites, GABA(B2) is of central importance in the functional coupling of heteromeric GABA(B) receptors to G-proteins and the subsequent activation of effector systems.
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Affiliation(s)
- A R Calver
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW, United Kingdom.
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41
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Farmer MK, Robbins MJ, Medhurst AD, Campbell DA, Ellington K, Duckworth M, Brown AM, Middlemiss DN, Price GW, Pangalos MN. Cloning and characterization of human NTT5 and v7-3: two orphan transporters of the Na+/Cl- -dependent neurotransmitter transporter gene family. Genomics 2000; 70:241-52. [PMID: 11112352 DOI: 10.1006/geno.2000.6387] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Orphan transporters form a growing subfamily of genes related by sequence similarity to the Na+/Cl- -dependent neurotransmitter superfamily. Using a combination of database similarity searching and cloning methods, we have identified and characterized two novel human orphan transporter genes, v7-3 and NTT5. Similar to other known orphan transporters, v7-3 and NTT5 contain 12 predicted transmembrane domains, intracellular N- and C-terminal domains, and large extracellular loops between transmembrane (TM) domains 3 and 4 and between TM domains 7 and 8. Residues within the extracellular loops are also predicted to contain sites for N-linked glycosylation. Human v7-3, the species orthologue of rat v7-3, contains an open reading frame (ORF) of 730 amino acids. Human NTT5 is a new member of the orphan transporter family and has an ORF of 736 amino acids. The amino acid sequences of human v7-3 and NTT5 are greater than 50% similar to other known orphan neurotransmitter transporters and also show sequence similarity to the human serotonin and dopamine transporters. Radiation hybrid mapping located the human v7-3 and NTT5 genes on chromosomes 12q21.3-q21.4 and 19q13.1-q13.4, respectively. Human mRNA distribution analysis by TaqMan reverse transcription-polymerase chain reaction showed that v7-3 mRNA is predominantly expressed in neuronal tissues, particularly amygdala, putamen, and corpus callosum, with low-level expression in peripheral tissues. In contrast, NTT5 mRNA was highly expressed in peripheral tissues, particularly in testis, pancreas, and prostate. Transient transfection with epitope-tagged transporter constructs demonstrated v7-3 to be expressed at the cell surface, whereas NTT5 was predominantly intracellular, suggestive of a vesicular location. Although the substrates transported by these transporters remain unknown, their specific but widespread distribution suggests that they may mediate distinct and important functions within the brain and the periphery.
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Affiliation(s)
- M K Farmer
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW, United Kingdom
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Wood MD, Murkitt KL, Rice SQ, Testa T, Punia PK, Stammers M, Jenkins O, Elshourbagy NA, Shabon U, Taylor SJ, Gager TL, Minton J, Hirst WD, Price GW, Pangalos M. The human GABA(B1b) and GABA(B2) heterodimeric recombinant receptor shows low sensitivity to phaclofen and saclofen. Br J Pharmacol 2000; 131:1050-4. [PMID: 11082110 PMCID: PMC1572438 DOI: 10.1038/sj.bjp.0703682] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2000] [Accepted: 09/04/2000] [Indexed: 11/08/2022] Open
Abstract
1. The aim of this study was to characterize the pharmacological profile of the GABA(B1)/GABA(B2) heterodimeric receptor expressed in Chinese hamster ovary (CHO) cells. We have compared receptor binding affinity and functional activity for a series of agonists and antagonists. 2. The chimeric G-protein, G(qi5), was used to couple receptor activation to increases in intracellular calcium for functional studies on the Fluorimetric Imaging Plate Reader (FLIPR), using a stable GABA(B1)/GABA(B2)/G(qi5) CHO cell line. [(3)H]-CGP-54626 was used in radioligand binding studies in membranes prepared from the same cell line. 3. The pharmacological profile of the recombinant GABA(B1/B2) receptor was consistent with that of native GABA(B) receptors in that it was activated by GABA and baclofen and inhibited by CGP-54626A and SCH 50911. 4. Unlike native receptors, the GABA(B1)/GABA(B2)/G(qi5) response was not inhibited by high microMolar concentration of phaclofen, saclofen or CGP 35348. 5. This raises the possibility that the GABA(B1)/GABA(B2)/G(qi5) recombinant receptor may represent the previously described GABA(B) receptor subtype which is relatively resistant to inhibition by phaclofen.
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Affiliation(s)
- M D Wood
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW.
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43
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Langmead CJ, Szekeres PG, Chambers JK, Ratcliffe SJ, Jones DN, Hirst WD, Price GW, Herdon HJ. Characterization of the binding of [(125)I]-human prolactin releasing peptide (PrRP) to GPR10, a novel G protein coupled receptor. Br J Pharmacol 2000; 131:683-8. [PMID: 11030716 PMCID: PMC1572376 DOI: 10.1038/sj.bjp.0703617] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
GPR10 is a novel G-protein coupled receptor that is the human orthologue of rat Unknown Hypothalamic Receptor-1 (UHR-1). Human prolactin-releasing peptide (PrRP) has been identified as an endogenous ligand for GPR10, and occurs as 31 and 20 amino acid forms. The present study characterizes the binding of [(125)I]-PrRP-20 to HEK293 cells stably expressing GPR10 receptors. Specific binding of [(125)I]-PrRP-20 was saturable, and analysis suggested evidence of both high and low affinity sites, with K:(D:) values of 0.026+/-0.006 and 0.57+/-0.14 nM respectively, and B(max) values of 3010+/-400 and 8570+/-2240 fmol mg protein(-1) respectively. Kinetic studies were unable to distinguish two sites, but single site analysis of association and dissociation data produced a K:(D:) of 0.012 nM. Competition studies revealed that human and rat PrRP-20 and PrRP-31 all display high affinity for GPR10. A range of other drugs which are known ligands at receptors which share limited homology with GPR10 were also tested. None of the drugs tested, including the RF-amide neuropeptide FF, demonstrated any affinity for GPR10. Human PrRP-20 failed to alter basal or forskolin-stimulated levels of intracellular cyclic AMP in HEK293-GPR10 cells, suggesting that GPR10 does not couple via either G(s) or G(i). Functional studies using measurements of intracellular calcium confirmed that human and rat PrRP-20 and PrRP-31 are all potent, full agonists at the GPR10 receptor. The response was blocked both by thapsigargin, indicating mobilization of intracellular Ca(2+) stores. These studies indicate that [(125)I]-PrRP-20 is a specific, high affinity radioligand for GPR10. The availability of this radioligand binding assay will be a valuable tool for the investigation of the key features involved in PrRP binding and studies on the localization and function of GPR10.
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Affiliation(s)
- C J Langmead
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, Harlow, Essex, CM19 5AW.
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Routledge C, Bromidge SM, Moss SF, Price GW, Hirst W, Newman H, Riley G, Gager T, Stean T, Upton N, Clarke SE, Brown AM, Middlemiss DN. Characterization of SB-271046: a potent, selective and orally active 5-HT(6) receptor antagonist. Br J Pharmacol 2000; 130:1606-12. [PMID: 10928964 PMCID: PMC1572216 DOI: 10.1038/sj.bjp.0703457] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/1999] [Revised: 03/30/2000] [Accepted: 05/04/2000] [Indexed: 11/09/2022] Open
Abstract
SB-271046, potently displaced [(3)H]-LSD and [(125)I]-SB-258585 from human 5-HT(6) receptors recombinantly expressed in HeLa cells in vitro (pK(i) 8.92 and 9.09 respectively). SB-271046 also displaced [(125)I]-SB-258585 from human caudate putamen and rat and pig striatum membranes (pK(i) 8.81, 9.02 and 8.55 respectively). SB-271046 was over 200 fold selective for the 5-HT(6) receptor vs. 55 other receptors, binding sites and ion channels. In functional studies on human 5-HT(6) receptors SB-271046 competitively antagonized 5-HT-induced stimulation of adenylyl cyclase activity with a pA(2) of 8.71. SB-271046 produced an increase in seizure threshold over a wide-dose range in the rat maximal electroshock seizure threshold (MEST) test, with a minimum effective dose of < or =0.1 mg kg(-1) p.o. and maximum effect at 4 h post-dose. The level of anticonvulsant activity achieved correlated well with the blood concentrations of SB-271046 (EC(50) of 0.16 microM) and brain concentrations of 0.01-0.04 microM at C(max). These data, together with the observed anticonvulsant activity of other selective 5-HT(6) receptor antagonists, SB-258510 (10 mg kg(-1), 2-6 h pre-test) and Ro 04-6790 (1-30 mg kg(-1), 1 h pre-test), in the rat MEST test, suggest that the anticonvulsant properties of SB-271046 are likely to be mediated by 5-HT(6) receptors. Overall, these studies demonstrate that SB-271046 is a potent and selective 5-HT(6) receptor antagonist and is orally active in the rat MEST test. SB-271046 represents a valuable tool for evaluating the in vivo central function of 5-HT(6) receptors.
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Affiliation(s)
- C Routledge
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW.
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45
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Hirst WD, Minton JA, Bromidge SM, Moss SF, Latter AJ, Riley G, Routledge C, Middlemiss DN, Price GW. Characterization of [(125)I]-SB-258585 binding to human recombinant and native 5-HT(6) receptors in rat, pig and human brain tissue. Br J Pharmacol 2000; 130:1597-605. [PMID: 10928963 PMCID: PMC1572217 DOI: 10.1038/sj.bjp.0703458] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/1999] [Revised: 03/17/2000] [Accepted: 05/04/2000] [Indexed: 11/08/2022] Open
Abstract
SB-258585 (4-Iodo-N-[4-methoxy-3-(4-methyl-piperazin-1-yl)-phenyl]-benzen esulphonamide) is a high affinity ligand at 5-HT(6) receptors. It displays over 100 fold selectivity for the 5-HT(6) receptor over all other 5-HT receptors tested so far. SB-258585 has been radiolabelled, to high specific activity, for its characterization as a 5-HT(6) receptor selective radioligand. [(125)I]-SB-258585 bound, with high affinity, to a single population of receptors in a cell line expressing human recombinant 5-HT(6) receptors. Kinetic and saturation binding experiments gave pK(D) values of 9.01+/-0.09 and 9.09+/-0.02, respectively. In membranes derived from rat or pig striatum and human caudate putamen, [(125)I]-SB-258585 labelled a single site with high levels (>60%) of specific binding. Saturation analysis revealed pK(D) values of 8.56+/-0.07 for rat, 8.60+/-0.10 for pig and 8.90+/-0.02 for human. B(max) values for the tissues ranged from 173+/-23 and 181+/-25 fmol mg(-1) protein in rat and pig striatum, respectively, to 215+/-41 fmol mg(-1) protein in human caudate putamen. The pK(i) rank order of potency for a number of compounds, determined in competition binding assays with [(125)I]-SB-258585, at human caudate putamen membranes was: SB-271046>SB-258585>SB-214111>methiothepin>clozapine>5-Me-OT>5-HT>Ro 04-6790>mianserin>ritanserin=amitriptyline>5-CT>mesulergine. Similar profiles were obtained from pig and rat striatal membranes and recombinant 5-HT(6) receptors; data from the latter correlated well with [(3)H]-LSD binding. Thus, [(125)I]-SB-258585 is a high affinity, selective radioligand which can be used to label both recombinant and native 5-HT(6) receptors and will facilitate further characterization of this receptor subtype in animal and human tissues.
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Affiliation(s)
- W D Hirst
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW
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46
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Watson J, Collin L, Ho M, Riley G, Scott C, Selkirk JV, Price GW. 5-HT(1A) receptor agonist-antagonist binding affinity difference as a measure of intrinsic activity in recombinant and native tissue systems. Br J Pharmacol 2000; 130:1108-14. [PMID: 10882396 PMCID: PMC1572157 DOI: 10.1038/sj.bjp.0703394] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2000] [Revised: 03/27/2000] [Accepted: 03/27/2000] [Indexed: 11/09/2022] Open
Abstract
1. It has been reported that radiolabelled agonist : antagonist binding affinity ratios can predict functional efficacy at several different receptors. This study investigates whether this prediction is true for recombinant and native tissue 5-HT(1A) receptors. 2. Saturation studies using [(3)H]-8-OH-DPAT and [(3)H]-MPPF revealed a single, high affinity site (K(D)approximately 1 nM) in HEK293 cells expressing human 5-HT(1A) receptors and rat cortex. In recombinant cells, [(3)H]-MPPF labelled 3 - 4 fold more sites than [(3)H]-8-OH-DPAT suggesting the presence of more than one affinity state of the receptor. [(3)H]-Spiperone labelled a single, lower affinity site in HEK293 cells expressing h5-HT(1A) receptors but did not bind to native tissue 5-HT(1A) receptors. These data suggest that, in transfected HEK293 cells, human 5-HT(1A) receptors exist in different affinity states but in native rat cortical tissue the majority of receptors appear to exist in the high agonist affinity state. 3. Receptor agonists inhibited [(3)H]-MPPF binding from recombinant 5-HT(1A) receptors in a biphasic manner, whereas antagonists and partial agonists gave monophasic inhibition curves. All compounds displaced [(3)H]-8-OH-DPAT and [(3)H]-spiperone binding in a monophasic manner. In rat cortex, all compounds displaced [(3)H]-MPPF and [(3)H]-8-OH-DPAT in a monophasic manner. 4. Functional evaluation of compounds, using [(35)S]-GTPgammaS binding, produced a range of intrinsic activities from full agonism, displayed by 5-HT and 5-CT to inverse agonism displayed by spiperone. 5. [(3)H]-8-OH-DPAT : [(3)H]-MPPF pK(i) difference correlated well with functional intrinsic activity (r=0.86) as did [(3)H]-8-OH-DPAT : [(3)H]-spiperone pK(i) difference with functional intrinsic activity (r=0.96). 6. Thus agonist : antagonist binding affinity differences may be used to predict functional efficacy at human 5-HT(1A) receptors expressed in HEK293 cells where both high and low agonist affinity states are present but not at native rat cortical 5-HT(1A) receptors in which only the high agonist affinity state was detectable.
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Affiliation(s)
- J Watson
- Neuroscience Research, SmithKline Beecham Pharmaceuticals, NFSP, Harlow, Essex, CM19 5AW, UK
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Hagan JJ, Price GW, Jeffrey P, Deeks NJ, Stean T, Piper D, Smith MI, Upton N, Medhurst AD, Middlemiss DN, Riley GJ, Lovell PJ, Bromidge SM, Thomas DR. Characterization of SB-269970-A, a selective 5-HT(7) receptor antagonist. Br J Pharmacol 2000; 130:539-48. [PMID: 10821781 PMCID: PMC1572114 DOI: 10.1038/sj.bjp.0703357] [Citation(s) in RCA: 233] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2000] [Revised: 03/14/2000] [Accepted: 03/14/2000] [Indexed: 11/08/2022] Open
Abstract
The novel 5-HT(7) receptor antagonist, SB-269970-A, potently displaced [(3)H]-5-CT from human 5-HT(7(a)) (pK(i) 8.9+/-0.1) and 5-HT(7) receptors in guinea-pig cortex (pK(i) 8.3+/-0.2). 5-CT stimulated adenylyl cyclase activity in 5-HT(7(a))/HEK293 membranes (pEC(50) 7.5+/-0.1) and SB-269970-A (0.03 - 1 microM) inhibited the 5-CT concentration-response with no significant alteration in the maximal response. The pA(2) (8.5+/-0.2) for SB-269970-A agreed well with the pK(i) determined from [(3)H]-5-CT binding studies. 5-CT-stimulated adenylyl cyclase activity in guinea-pig hippocampal membranes (pEC(50) of 8.4+/-0.2) was inhibited by SB-269970-A (0.3 microM) with a pK(B) (8.3+/-0.1) in good agreement with its antagonist potency at the human cloned 5-HT(7(a)) receptor and its binding affinity at guinea-pig cortical membranes. 5-HT(7) receptor mRNA was highly expressed in human hypothalamus, amygdala, thalamus, hippocampus and testis. SB-269970-A was CNS penetrant (steady-state brain : blood ratio of ca. 0.83 : 1 in rats) but was rapidly cleared from the blood (CLb=ca. 140 ml min(-1) kg(-1)). Following a single dose (3 mg kg(-1)) SB-269970 was detectable in rat brain at 30 (87 nM) and 60 min (58 nM). In guinea-pigs, brain levels averaged 31 and 51 nM respectively at 30 and 60 min after dosing, although the compound was undetectable in one of the three animals tested. 5-CT (0.3 mg kg(-1) i.p.) induced hypothermia in guinea-pigs was blocked by SB-269970-A (ED(50) 2.96 mg kg(-1) i.p.) and the non-selective 5-HT(7) receptor antagonist metergoline (0.3 - 3 mg kg(-1) s.c.), suggesting a role for 5-HT(7) receptor stimulation in 5-CT induced hypothermia in guinea-pigs. SB-269970-A (30 mg kg(-1)) administered at the start of the sleep period, significantly reduced time spent in Paradoxical Sleep (PS) during the first 3 h of EEG recording in conscious rats.
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Affiliation(s)
- J J Hagan
- Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW
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Thomas DR, Atkinson PJ, Ho M, Bromidge SM, Lovell PJ, Villani AJ, Hagan JJ, Middlemiss DN, Price GW. [(3)H]-SB-269970--A selective antagonist radioligand for 5-HT(7) receptors. Br J Pharmacol 2000; 130:409-17. [PMID: 10807680 PMCID: PMC1572078 DOI: 10.1038/sj.bjp.0703318] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Binding of the 5-HT(7) receptor antagonist radioligand [(3)H]-SB-269970 to human 5-HT(7(a)) receptors expressed in HEK293 cell membranes (h5-HT(7(a))/293) and to guinea-pig cerebral cortex membranes, was characterized and compared with [(3)H]-5-CT binding. [(3)H]-SB-269970 (1 nM) showed full association with h5-HT(7(a))/293 membranes after 40 min. Specific binding at equilibrium represented >90% of total binding and was fully reversible by methiothepin (10 microM), full dissociation occurring by 100 min. The association (k(+1)) and dissociation (k(-1)) rate constants were 0.05 nM(-1)min(-1) and 0.05 min(-1) respectively, giving a K(D) (k(-1)/k(+1)) of 1.0 nM. [(3)H]-SB-269970 bound saturably and apparently monophasically to both h5-HT(7(a))/293 and guinea-pig cortex membranes, with K(D) values of 1.25+/-0.05 and 1.7+/-0.3 nM respectively. The B(max) for [(3)H]-SB-269970 to both h5-HT(7(a))/293 and guinea-pig cortex membranes (5780+/-380 and 125+/-8.2 fmoles mg protein(-1) respectively) was similar to that for [(3)H]-5-CT (6190+/-940 and 143+/-19 fmoles mg protein(-1) respectively). These data suggest that, in each tissue, both radioligands labelled the same population of receptors, which appear to be present in an agonist high affinity state. The profile of compound inhibition of [(3)H]-SB-269970 binding to h5-HT(7(a))/293 and guineapig cortex membranes correlated well (corr. coeff. 0.98) with those for [(3)H]-5-CT binding and were consistent with the profiles reported previously for the human 5-HT(7(a)) and guinea-pig cortex 5-HT(7) receptors using [(3)H]-5-CT. Hill slopes for inhibition of [(3)H]-SB-269970 and [(3)H]-5-CT binding were close to 1, consistent with binding to a single receptor population in both tissues. [(3)H]-SB-269970 represents the first selective 5-HT(7) antagonist radioligand, which should aid further characterization of 5-HT(7) receptors in recombinant and native tissues and help establish their role in brain function.
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Affiliation(s)
- D R Thomas
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW.
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Abstract
The P300 is a long-latency cognitive event-related potential (ERP) elicited by the presentation of relevant target stimuli. Unfortunately, the standard ERP recording technique takes no account of the background EEG during stimulus presentation. However, a recently developed technique (interactive recording) controls for variability in the EEG by applying stimuli only when the background EEG is in a predetermined state. The use of the interactive technique has led to significant changes in the P300 amplitude in control studies. Since P300 amplitude data are commonly used in schizophrenia research, and have previously been associated with cognitive deficits in schizophrenia, we studied the effects of interactive recording in a schizophrenia population. The same ERP paradigm was implemented twice for each subject, using both standard ERP and the interactive recording techniques. There was a significant increase in the amplitude of the P300 peak with interactive recording, although no significant change in latency. The results indicate that the effect of background EEG may need to be taken into account when conducting general ERP-based studies in schizophrenia. The results also indicate that the method may be used to investigate the effects of EEG variation on ERP values and, by implication, on cognitive processes. In particular, the recognition of EEG states that lead to a higher amplitude ERP value may aid in the further development of EEG investigations of schizophrenia. A similar development is indicated between cognitive research in schizophrenia and the sub-second brain-states in which cognitive function may be reflected.
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Affiliation(s)
- G W Price
- Queensland Centre for Schizophrenia Research, Wolston Park Hospital, Brisbane, Australia.
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Middlemiss DN, Göthert M, Schlicker E, Scott CM, Selkirk JV, Watson J, Gaster LM, Wyman P, Riley G, Price GW. SB-236057, a selective 5-HT1B receptor inverse agonist, blocks the 5-HT human terminal autoreceptor. Eur J Pharmacol 1999; 375:359-65. [PMID: 10443589 DOI: 10.1016/s0014-2999(99)00262-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel compound, SB-236057 (1'-ethyl-5-(2'-methyl-4'-(5-methyl-1,3,4-oxadiazol-2-yl)biphenyl- 4-carbonyl)-2,3,6,7-tetrahydrospiro[furo[2,3-f]indole-3,4'-piperid ine]) has been shown to have high affinity for human 5-hydroxytryptamine1B (5-HT1B) receptors (pKi = 8.2) and displays over 75 or more-fold selectivity for the human 5-HT1B receptor over other 5-HT receptors, including the human 5-HT1D receptor, and a range of other receptors, ion channels and enzymes. In functional studies using [35S]GTPgammaS binding, SB-236057 displayed negative intrinsic activity (pEC50 = 8.0) at human 5-HT1B receptors stably expressed in Chinese Hamster Ovary (CHO) cells and caused a rightward shift of agonist concentration response curves consistent with competitive antagonism (pA2 = 8.9). SB-236057 potentiated [3H]5-HT release from electrically stimulated guinea pig or human cortical slices. SB-236057 also abolished the inhibitory effect of exogenously superfused 5-HT on electrically-stimulated release from slices of the guinea pig cortex. These studies using SB-236057 confirm that, in both the guinea pig and human cerebral cortex, the terminal 5-HT autoreceptor is of the 5-HT1B subtype.
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Affiliation(s)
- D N Middlemiss
- Department of Neurosciences, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex, UK
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