Mitigating abiotic stresses using natural and modified stilbites synergizing with changes in oxidative stress markers in aquaculture

Medicinal and aromatic plants assisted bioremediation of ammonical and bacterial contaminants in aquaponics water

An experiment was conducted under laboratory conditions to examine the effect of sixteen medicinal and aromatic plants (MAPs), namely Aloe barbadensis, Cymbopogen citratus, Bacopa monnieri, Senna sigueana, Plantado ovata, Asparagus racemosses, Phylanthus emblica, Vitex negundo, Cammiphora wightii, Cymbopogon martini, Andrographis paniculate, Ocimum tenuiflorum, Gymnema sylvestre, Centella asiatica, Adhatoda vasica, and Cyamopsis tetragonoloba in the removal of total ammonia-N (TAN) from aquaponics water. The different dried and grounded MAPs were added @ 100 mgl-1 into individual conical flasks containing 100 ml aquaponics water (spiked with 5 mgl-1 ammonia) and placed in a shaker. The effectiveness of different MAPs in removing TAN was evaluated at 24 hrs intervals until one of the MAPs achieved a removal rate of over 80%. The study also investigated their potential activity against fish bacterial pathogens viz. Edwardsiella tarda, Escherichia coli, Vibrio parahaemolyticus, Aeromonas hydrophila, and Staphylococcus aureus using the agar well diffusion method. The study indicates a negligible removal of TAN in the first twelve hours for all the MAPs. TAN concentration significantly reduced from 24 hrs for amla-treated water followed by satavari-treated water. Within 96 hrs., amla, satavari, and jalbrahmi removed 88.13 ± 0.81%, 79.52 ± 2.27%, and 77.22 ± 0.70 of TAN respectively. Other MAPs showed little effectiveness in removing ammonia, while cluster beans and ardushi increased the ammonia level in the water. Additionally, the methanol extract of amla exhibited strong antibacterial activities against all tested pathogens especially, against E. tarda. This study suggests the potential application of a MAP-based One-Health approach for mitigating abiotic and biotic stresses in aquaculture. PRACTITIONER POINTS: Evaluated 16 different medicinal and aromatic plants (MAPs) for their ammonia removal activity from aquaponics water. Amla treated water showed the highest ammonia removal followed by Satavaari and Jalbrahmi. Cluster beans and Ardushi treated water resulted in increasing ammonia levels due to their high nitrogen contents. Methanolic extract of amla showed bactericidal activity against fish pathogens Edwardsiella tarda, E. coli, Vibrio parahaemolyticus, A. hydrophila, and S. aureus. Potential applications in developing aquaponics production system of fish with medicinal plants through nutrient cycling and water recycling.

Biomitigation of ammonical stress in aquaculture using luffa sponge coupled with medicinal and aromatic plants for potential application in aquaponics

Ammonia, a major stress-inducing factor in aquaculture, contributes a significant challenge in maintaining sustainable fish production. Addressing this issue requires environmentally and economically sustainable solutions. This study explores the use of readily available and environmentally friendly porous lignocellulosic luffa sponge as a biostimulator, with a combination of three medicinal and aromatic plants(MAPs) viz. Asparagus racemosses(satavari) roots, Cammiphora wightii(guggal) stems, and Vitex negundo(nirgundi) stem for alleviating ammoniacal stress by biotransforming ammonia in aquaponics water/ aquaculture. A 45-day experiment was conducted using Pangasianodon hypophthalmus in tanks containing aquaponics water. The study consists of a control (C) and four treatments: L(Luffa), LS(Luffa + shatavari roots), LG(Luffa + guggal stem) and LN(Luffa + nirgundi stem). Ammonia was spiked weekly at different concentrations(2, 2.5, 3, 5, and 10 mgL-1). The L group showed significantly(p < 0.05) higher ammonia removal of 86.06% ± 9.62(spiked 3 mgL-1) in 24 hrs, and 73.98%±2.6 and 86.35%±4.47(spiked 5 mgL-1) in 24 and 48 hrs, respectively, which may be attributed to a higher surface area of the substrate for microbial attachment. The MAPs upregulated fish's hematological and serum biochemical parameters under elevated ammonia, indicating ammonical stress mitigation. Treatment groups showed significantly (p < 0.05) higher fish yield than the control (165.66 ± 0.50 g), with L, LS, LG, and LN giving a yield of 174.76 ± 2.07, 175.41 ± 0.59, 179.07 ± 4.29, and 181.57 ± 0.45 g respectively, with no significant difference detected among them. Promising outcomes in ammonia removal and stress mitigation were demonstrated by incorporating the lignocellulosic biomass and MAPs in this study, which is beneficial in commercial aquaculture with prospects in aquaponics systems.

Speciation-specific chromium bioaccumulation and detoxification in fish using hydrogel microencapsulated biogenic nanosilver and zeolite synergizing with biomarkers

Grass carp intestinal waste-mediated biosynthesized nanosilver (AgNPs) was valorized using guaran and zeolite matrices, resulting in AgNPs-guaran, AgNPs-zeolite, and AgNPs-guaran -zeolite composites. The valorized products were examined using Environmental Scanning Electron Microscopy, Energy Dispersive X-ray analysis and X-ray Diffraction analysis to confirm uniform dispersion and entrapment of AgNPs within the matrixes. These valorized products were evaluated for their efficacy in detoxifying the ubiquitous and toxic hexavalent chromium (Cr6+) in aquatic environments, with Anabas testudineus exposed to 2 mg l-1 of Cr6+ for 60 days. Remarkable reduction of Cr6+ concentration to 0.86 ± 0.007 mg l-1 was achieved with AgNPs-guaran-zeolite composite, indicating successful reclamation of contaminated water and food safety assurance. Consistency in results was further corroborated by minimal stress-related alterations in fish physiological parameters and integrated biomarker response within the experimental group treated with the AgNPs-guaran-zeolite composite. Despite observed chromium accumulation in fish tissues, evidence of physiological stability was apparent, potentially attributable to trivalent chromium accumulation, serving as an essential nutrient for the fish. Additionally, the challenge study involving Anabas testudineus exposed to Aeromonas hydrophila exhibited the lowest cumulative mortality (11.11%) and highest survival rate (87.5%) within the same experimental group. The current study presents a novel approach encompassing the valorization of AgNPs for Cr6+ detoxification under neutral to alkaline pH conditions, offering a comprehensive framework for environmental remediation.

Modification of natural zeolites and their applications for heavy metal removal from polluted environments: Challenges, recent advances, and perspectives

In recent decades, environmental pollution has become a significant problem for human health and environmental impact. The high accumulation of heavy metals in waters and soils from different sources was conducted by finding efficient and environmentally friendly treatment methods and materials for their removal. Natural zeolites have found wide-ranging applications in environmental remediation and protection, considering various treatment and modification methods designed to enhance the natural zeolites' adsorptive or ion-exchange capabilities for increased efficiency. This paper briefly consolidates the recent scientific literature related to the main characteristics of natural and modified zeolites, the advantages and limitations of their environmental remediation application, and summarizes the methodologies applied to natural zeolites in order to improve their properties. Their application for removing heavy metals from water systems and soils is also comprehensively discussed. This review highlights the excellent potential of natural zeolites to be used after specific treatment or modification as a sustainable and green material to solve numerous environmental pollution issues.

Plants, animals, and fisheries waste-mediated bioremediation of contaminants of environmental and emerging concern (CEECs)-a circular bioresource utilization approach

The release of contaminants of environmental concern including heavy metals and metalloids, and contaminants of emerging concern including organic micropollutants from processing industries, pharmaceuticals, personal care, and anthropogenic sources, is a growing threat worldwide. Mitigating inorganic and organic contaminants, which can be coined as contaminants of environmental and emerging concern (CEECs), is a big challenge as traditional physicochemical processes are not economically viable for managing mixed contaminants of low concentrations. As a result, low-cost materials must be designed to provide high CEEC removal efficiency. One of the environmentally viable and energy-efficient approaches is biosorption, which involves using biomass or biopolymers isolated from plants or animals to decontaminate heavy metals in contaminated environments using inherent biological mechanisms. Among chemical constituents in plant biomass, cellulose, lignin, hemicellulose, proteins, polysaccharides, phenolic compounds, and animal biomass include polysaccharides and other compounds to bind heavy metals covalently and non-covalently. These functional groups include carboxyl, hydroxyl, carbonyl, amide, amine, and sulfhydryl. Cation-exchange capacities of these bioadsorbents can be improved by applying chemical modifications. The relevance of chemical constituents and bioactives in biosorbents derived from agricultural production such as food and fodder crops, bioenergy and cash crops, fruit and vegetable crops, medicinal and aromatic plants, plantation trees, aquatic and terrestrial weeds, and animal production such as dairy, goatery, poultry, duckery, and fisheries is highlighted in this comprehensive review for sequestering and bioremediation of CEECs, including as many as ten different heavy metals and metalloids co-contaminated with other organic micropollutants in circular bioresource utilization and one-health concepts.