A review on phorate persistence, toxicity and remediation by bacterial communities

Pesticides are an integral part in maintaining agriculture and horticultural productivity and play a vital role in meeting the increasing food, fiber, and fuel needs of the growing population. Globally, organophosphate pesticides(OPPs) are among the most common pesticides used due to their high proficiency and relatively low persistence in the environment. However, recent studies have reported problems due to pesticide use, e.g., phorate contamination of aquatic ecosystems(fresh and groundwater), sediments, fruits and vegetables, and forage crops. This review highlights many cases where phorate has been detected above its respective maximum residue limit values. Organophosphate pesticides, including phorate, have negative impacts on both the environment and human health. The ecological and public health concerns of recurrent pesticide utilization have encouraged the research related to environmental fate of pesticides.Bioremediation is an effective, eco-friendly, and financially viable approach for the decontamination and degradation of toxic OPPs from the environment,compared to the costly, unecological, and time-consuming physicochemical approaches, which lead to the generation of byproducts of higher toxicity.Researchers have recognized that a wide range of microbes, mainly bacteria, can degrade this extremely hazardous pesticide. Therefore, this review discusses the present pesticide scenarios, especially phorate contamination, its toxicity, biodegradation, and metabolic products via bacterial communities, both in India and globally. The latest and up-to-date literatures on the use, contamination, and bacterial application of phorate degradation are also summarized. This article offers national and international food safety organizations and public health authorities the ability to be involved in preventing the risks associated with the use of food and nutrition products contaminated with extremely toxic phorate pesticide. This article would also enable researchers to develop comprehensive and sustainable methods to effectively remediate pesticide-contaminated environments. In conclusion, it is envisaged that the successful application of bacterial communities for degradation of phorate would help in understanding the fate and persistence of such toxic pollutants in a better way.     

Review of applying material flow analysis-based studies for a sustainable Norwegian Salmon aquaculture industry

ABSTRACT

Since its beginning in the early 70thies, the fast growing Atlantic salmon aquaculture industry in Norway has been and still is an object for research across numerous disciplines and research fields. This article presents an overview of the research studies applying Material Flow Analysis (MFA) based methods on Norwegian Aquaculture of Atlantic Salmon starting from 2004 until 2018. The studies were reviewed in relation to their applied method, involved institutions, flows, data acquisition, and suggestions for improvement. All of the reviewed studies applied different MFA methods suitable to the objective of each study, were done with involvement of multiple institutions and stakeholders, modeled credible data and provided specific suggestions for reducing the environmental impacts and optimizing nutrients utilization efficiency. The review concludes that MFA-based methods have the potential for having a functional role within the framework of the Norwegian Salmon Aquaculture industry’s sustainable development. A key factor in fulfilling that potential would be diversifying the objectives of MFA research to be more inclusive of the three pillars of sustainability: environment, economy, and society.     

Breakdown Products in the Metabolic Pathway of Anthracene Degradation by a Ligninolytic Fungus Polyporus sp. S133

Polyporus sp. S133 fungi were selected based on their ability to degrade anthracene in liquid media. The degradation efficiency of anthracene increased by adding 0.5% Tween 80 to reach 71%; agitation at 120 rev/min increased the degradation to 92% after 30?days of incubation. Enzymes such as manganese peroxidase (MnP), lignin peroxidase (LiP), laccase, 1,2-dioxygenase and 2,3-dioxgenase were produced by Polyporus sp. S133 during incubation, and the highest enzyme activity was 182.3 U l^?1 by 1,2-dioxygenase after 20?days of incubation. These results indicate that ligninolytic and dioxygenase enzymes secreted from Polyporus sp. S133 could play an important role in anthracene degradation efficiency. The metabolites detected through the degradation pathway were anthraquinone, phthalic acid, benzoic acid and catechol.     

Decolorization and Metabolism of Anthraquionone-Type Dye by Laccase of White-Rot Fungi Polyporus sp. S133

Utilization of microbes including white-rot fungi and bacterial strains for decolorization of synthetic dyes is one promising strategy of an environmentally friendly and cost-competitive alternative to physico-chemical decomposition processes for treating industrial effluents. In this study, the biodegradation ability of the white-rot fungi Polyporus sp. S133 that produce high laccase was investigated in order to decolorize anthraquinone-type dye. Parameter including pH, temperature, and non-ionic surfactant were used to comparatively study the decolorizing effects on Remazol Brilliant Blue R (RBBR). The purified laccase totally decolorized 200 mg L⁻¹ initial concentration of RBBR dye when only 1.5 U L⁻¹ of laccase was used in the reaction mixture. The optimal decolorization rates were achieved at pH 5 and at a temperature of 50°C. N-hydroxybenzotriazole, a small molecular weight redox mediator, was found to accelerate the decolorization. Tween 20 inhibited the decolorization while Tween 80 and Brij 35 showed no inhibition effect. Two compounds were identified as the intermediates (m/z 304.3 and m/z 342.2). These results suggest that laccase from Polyporus sp. S133 is a powerful tool for the decolorization of anthraquinone dyes. A pathway for the metabolism of the RBBR by laccase of Polyporus sp S133 was proposed. These proposed pathways could contribute to a better comprehension of the mechanisms used by oxidative enzymes to transform organic compounds.     

Correlation Study between Land Use, Water Quality, and Heavy Metals (Cd, Pb, and Zn) Content in Water and Green Lipped Mussels Perna viridis (Linnaeus.) at the Johor Strait

In order to observe the variation in land use changes, satellite images from the Landsat Thematic Mapper (TM) and the Enhanced Thematic Mapper (ETM) for 1991, 2000, 2005, and 2008 were used to compare the differences between selected water quality parameters, including heavy metal (Cd, Pb, and Zn) content in both water and green mussels or Perna viridis (Linnaeus.) before and after the increase in land use activities beginning from 2006. The samples were collected at 11 points for water and 4 points for green mussels between the Second Link and the Causeway Link at the Johor Strait in 2009 and were analyzed for pH, temperature degrees Celsius), dissolved oxygen, ammoniacal nitrogen, and heavy metal (Cd, Pb, and Zn) content.     

Removal of Arsenic, Boron, and Selenium from Excavated Rocks by Consecutive Washing

This paper describes the leaching behavior and release mechanisms of arsenic (As), boron (B), and selenium (Se) from excavated rocks using sequential extraction for solid-phase fractionation, batch experiments with pH variation, and consecutive batch experiments with changes in the solid?Cliquid mixing ratios. Arsenic in the excavated rock was mostly found with the sulfides/organic matter fraction while majority of the leachable B and Se were associated with the exchangeable phases. The leaching of As was strongly pH dependent, Se was pH dependent only around the acidic region, and B was pH independent. Consecutive washing technique with deionized water effectively lowered the B and Se concentrations in the leachate below the drinking water standards of Japan, but was inefficient in the removal of As. Arsenic exhibited non-conservative leaching behavior and its movement was affected by processes like dissolution, precipitation, and pyrite oxidation. In contrast, B and Se behaved more conservatively, resulting in their easy removal from the excavated rock by simple washing and dilution.     

Removal of Bisphenol A from Aqueous Solution by Activated Carbon Derived from Oil Palm Empty Fruit Bunch

Land use specific deposition velocities of atmospheric trace gases and aerosols—particularly of reactive nitrogen compounds—are a fundamental input variable for a variety of deposition models. Although the concept is known to have shortcomings—especially with regard to bi-directional exchange—the often limited availability of concentration data and meteorological input variables make it a valuable simplification for regional modeling of deposition fluxes. In order to meet the demand for an up-to-date overview of recent publications on measurements and modeling studies, we compiled a database of ammonia (NH₃) deposition velocities published from 2004 to 2013. Observations from a total of 42 individual studies were averaged using an objective weighing scheme and classified into seven land use categories. Weighted average and median deposition velocities are 2.2 and 2.1 cm s^?1 for coniferous forests, 1.5 and 1.2 cm s^?1 for mixed forests, 1.1 and 0.9 cm s^?1 for deciduous forests, 0.9 and 0.7 cm s^?1 for semi-natural sites, 0.7 and 0.8 cm s^?1 for urban sites, 0.7 and 0.6 cm s^?1 for water surfaces, and 1.0 and 0.4 cm s^?1 for agricultural sites, respectively. Thus, values presented in this compilation were considerably lower than those found in former studies (e.g., VDI 2006). Reasons for the mismatch were likely due to different land use classification, different averaging methods, choices of measurement locations, and improvements in measurement and in modeling techniques. Both data and code used for processing are made available as supplementary material to this article.     

Effect of cold shock and hormone on growth and male morphotypes of freshwater prawn,Macrobrachium rosenbergii (de Man)

A study was carried out to determine the effects of cold shock and 17α‐methyl testosterone hormone on growth in male morphotypes of giant freshwater prawn Macrobrachium rosenbergii. Juvenile males were exposed at 18 ± 0.25°C for 24 h with normal feed and cultured at 27 ± 0.7°C for 70 days as well as administrated feed with hormone separately at 400 mg kg^?1 feed for the first 30 days of culture period (70 days). The growth (Mean ± SD) of male juveniles at harvest was closely homogenous in the cold shock (CLS) treated group; while it was heterogeneous in hormone‐treated (MH) and control (CO) groups. Although total body weight of blue claw (BC) males was not significantly different in the controls and the treatments, the 2nd pereiopods (claw) weight and length of the BC was significantly lower in CLS (0.52 ± 0.05 g, 10.02 ± 0.65 cm) than that in the CO (0.71 ± 0.16 g, 12.53 ± 0.57 cm) and MH (0.75 ± 0.08 g, 12.85 ± 1.18 cm) treatments. Survival of prawns was similar in treatments. The morphotypes of male prawn were significantly different with 59% of BC males with small‐sized claws in CLS and, 45% and 30% of BC males with large‐sized claws in MH and CO respectively. Cold shock adversely affected male morphotypes of the prawn so that numbers of BC males with small‐sized claw was the highest in CLS tank. However, the CLS treatment resulted in more uniform marketable prawns and suggested a high production of BC males in an all‐male culture system.