Cytogenetic bioassays in model plants to evaluate the environmental toxicity of pharmaceutical residues.

BackgroundMethane production as biofuels is a fast and strong growing technique for renewable energy. Substrates like waste (e.g. food, sludge from waste water treatment plants (WWTP), industrial wastes) can be used as a suitable resource for methane gas production, but in some cases, with elevated toxicity in the digestion residue. Former investigations have shown that co-digesting of contaminated waste such as sludge together with other substrates can produce a less toxic residue. In addition, wetlands and reed beds demonstrated good results in dewatering and detoxifying of sludge. The aim of the present study was to investigate if the toxicity may alter in industrial sludge co-digested with oat and post-treatment in reed beds. In this study, digestion of sludge from Bjorkborn industrial area in Karlskoga (reactor D6) and co-digestion of the same sludge mixed with oat (reactor D5) and post-treatment in reed beds were investigated in parallel. Methane production as well as changes in cytotoxicity (Microtox(R); ISO 11348–3), genotoxicity (Umu-C assay; ISO/13829) and AhR-mediated toxicity (7-ethoxyresorufin-O-deethylase (EROD) assay using RTW cells) were measured.ResultsThe result showed good methane production of industrial sludge (D6) although the digested residue was more toxic than the ingoing material measured using microtox30min and Umu-C. Co-digestion of toxic industrial sludge and oat (D5) showed higher methane production and significantly less toxic sludge residue than reactor D6. Furthermore, dewatering and treatment in reed beds showed low and non-detectable toxicity in reed bed material and outgoing water as well as reduced nutrients.ConclusionsCo-digestion of sludge and oat followed by dewatering and treatment of sludge residue in reed beds can be a sustainable waste management and energy production. We recommend that future studies should involve co-digestion of decontaminated waste mixed with different non-toxic material to find a substrate mixture that produce the highest biogas yield and lowest toxicity within the sludge residue.

The tropical and subtropical naturalized physic nut (Jatropha curcas L.), has been explored for biodiesel production in recent times. The oil is extracted from the seeds and, for the production to be feasible, utilization of the residual seed cake is crucial. Although the cake could be employed as a protein source in animal feed, it is rich in phorbol ester, which is toxic for animals. Therefore, breeding programs have been working to reduce or eliminate the phorbol ester content in physic nut. In this context, the present work aimed to evaluate the physic nut oil of toxic and non-toxic varieties (containing known or undetectable amounts of phorbol ester, respectively) with regards to phytotoxicity in a model experiment with Lactuca sativa L. For this, the percentage of germinated seeds was evaluated after 8, 16, 24, 36 and 48 hours of exposure to the treatments with toxic and non-toxic oil at concentrations of 22.5 %, 45 % and 67.5 % of emulsion (physic nut oil energetically mixed with distilled water). Root growth was determined after 48 hours of exposure and the germination speed index was obtained. The different stages of mitotic division as well as possible chromosomal and nuclear alterations were also recorded. The mitotic index was calculated as the number of dividing cells, as a fraction of the total number of cells, and the frequency of chromosome and nuclear alterations, expressed as the percentage of number of alterations divided by the total number of cells. Both varieties exhibited phytotoxicity, inducing significant reductions in percentage of germinated seeds (reduction of 98 %), germination speed index (reduction of 24.44) and root growth (reduction of 8.54 mm). In microscopic analysis, a mitodepressive effect was observed for both oils at the three concentrations used when compared to the negative control; however, it was possible to distinguish between the toxic and the non-toxic varieties based on the more expressive reduction of division promoted by the first, 2.19 %. Significant increments in the frequency of mitotic cells showing chromosome alterations as well, as the presence of condensed nuclei, were observed in the treated cells. However, these parameters were not significantly different from the control in the cells treated with both physic nut oils. In conclusion, the evaluation of root growth and cell division in the plant model L. sativa, can be proposed as an alternative to animal tests to distinguish the varieties with high and low phorbol ester concentration, thus contributing to the detection of toxicity in varieties used in breeding programs. Rev. Biol. Trop. 66(2): 495-502. Epub 2018 June 01.

Neonicotinoid insecticides are the most widely used class of insecticides worldwide. Concern has grown over their widespread environmental presence and potential unintended adverse effects. The present study examined hydrolysis and photolysis reaction rates of neonicotinoids and assessed any residual toxicity of reaction products. Hydrolysis rates were tested between pH 4 and 10 and found to be base-catalyzed. Experiments revealed a nonelementary rate law for hydrolysis, with the hydroxide concentration raised to a power of 0.55 ± 0.09, which has implications for accurate prediction of environmental half-lives. Divalent metal ions (Cu2+ , Ni2+ , Zn2+ ) and minerals (kaolinite, goethite, TiO2 ) had no effect on hydrolysis rates. The hydrolysis rate in a natural water, however, was slower than that predicted by buffered experiments. Nitenpyram, imidacloprid, thiamethoxam, and clothianidin reacted via direct photolysis in both ultrapure and natural waters, with average quantum yields of 0.024 ± 0.001, 0.0105 ± 0.0002, 0.0140 ± 0.0002, and 0.0101 ± 0.0001, respectively. Acetamiprid primarily underwent indirect photolysis by reaction with OH· (1.7 ± [0.2] × 109 M-1 s-1 ). For all compounds, the urea derivative was the most commonly detected product in both hydrolysis and photolysis experiments. Using mosquito (Culex pipiens) larvae, no residual toxicity of reaction products was observed. Results indicate long environmental half-lives for the tested neonicotinoids, which may help to explain their ubiquitous presence in environmental matrices. Environ Toxicol Chem 2018;37:2797-2809. © 2018 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Mitigation of organophosphorus insecticides from environment: Residual detoxification by bioweapon catalytic scavengers

The aim of this study was to evaluate in vitro antifungal potential of carrot seed extracts, its essential oil, different fractions, isolated compounds, and their derivatives against three phytopathogenic rice fungi (Fusarium moniliforme, Bipolaris oryzae, and Rhizoctonia solani) using poisoned food technique. Carrot seed essential oil was extracted using hydrodistillation method and extracts were prepared using different solvents viz. dichloromethane, hexane, and methanol. The pure compounds daucene, carotol, and daucol were isolated using column chromatography and derivatized using different reagents. The study demonstrated that antifungal potential of all tested compounds varied in a dose dependent manner. Structure activity relationship of isolated and derivatized compounds showed that polar moieties possessed more antifungal potential as compared to non-polar moieties. The results suggested that carrot seed methanol extract and carotol possessed strong antifungal potential as compared to other components tested. PRACTICAL APPLICATIONS: Phytopathogenic fungi are the major problems causing harmful damage to the rice crop. Only available control of these diseases is synthetic fungicides but their repeated use led to serious environmental issues, residual toxicity, and development of resistance. Therefore, it's better to find some natural alternatives. The current study was conducted to evaluate in vitro antifungal potential of carrot seed essential oil, its constituents and extracts against phytopathogenic fungi of rice. The methanol extract and carotol possessed highest antifungal potential which might be due to their polar nature. This information may add a new dimensions to biological activity of these natural molecules mainly in the field of agriculture as fungal diseases are found to be associated with major losses in agriculture. Hence these compounds can act as natural antifungal agents against rice fungi.

Economic losses due to infestation by the soybean armyworm, Spodoptera litura can reach up to 100%. Some farmers often used insecticide to control the armyworm. However, regular use of insecticide can cause several negative effects such as environmental pollution, residual toxicity, and health hazard for human. The objective of this research was to determine the larvicidal, antifeedant, and activities of clove leaf oil (CLO) against the armyworm S. litura on soybean. The research was carried out at the plant pest control laboratory of Politeknik Pembangunan Pertanian Malang. Clove leaf oil was evaluated for its larvicidal and antifeedant activities against ten third instar larvae of the armyworm. Completely randomized design was used with concentration levels of CLO as treatments. i.e. 0.4, 0.5, 0.67, 1.0, and 2.0% by volume. Profenofos 500 g L 0.1% and distilled water were include as control. Each treatment consisted of five replications. Mortality of the larvae and antifeedant activity were analyzed using analysis of variance, followed by probit analysis for calculating LC 50 and LT 50 -1. The results showed that CLO at 2.0% concentration was the most effective with regard to larvicidal and antifeedant activities. The LC 50 of CLO was 0.09% with LT 24.6 hours. This study revealed that the environmentally friendly CLO can be used as an alternative to synthetic insecticide for control S. litura.

Chapter 1 - Biopesticides: commercial opportunities and challenges

Aphicidal activity of five plant extracts applied singly or in combination with entomopathogenic bacteria, Xenorhabdus budapestensis against rose aphid, Macrosiphum rosae (Hemiptera: Aphididae)

Mango (Mangifera indica L.) anthracnose disease has been a challenging issue for the past several years, causing about 30%–60% economic loss in its annual production. Colletotrichum gloeosporioides survives as an endophyte, during later stages develops infection, thereby causing serious pre‐ as well as postharvest crop losses. Such losses become difficult to overcome as the supply of the fruit gets affected due to quality reduction as a result of anthracnose. For many decades, synthetic fungicides have been used as primary control measures to the disease. However, indiscriminate use of synthetic fungicides against the pathogen has raised concerns due to their detrimental effects on environmental health and residual toxicity in plants and fruits. The disease resistance and resurgence against synthetic fungicides have also been major threat to farming community and stakeholders. Given these harmful effects, researchers, agro‐industries, and farming communities are exploring sustainable alternatives to anthracnose disease in mango with phyto‐extracts and essential oils as promising options globally. This comprehensive review suggests eco‐friendly alternative for combating C. gloeosporioides in mango fruit. The effectiveness of plant‐based extracts and oils in preventing anthracnose‐related postharvest losses is highlighted, along with the future prospects for high‐quality mangoes. The botanical‐based management strategies can also provide a sustainable alternative to conventional synthetic control measures and reduce chemical load in the management of the disease during storage. In the context of climate change, developing and using these options will have a strong potential to address the challenges posed by chemicals.

Establishment of antitick efficacy of a phytoformulation prepared from Annona squamosa leaf extracts for the management of acaricide resistant tick infestations on cattle

Larvicidal and antifeedant activities of clove leaf oil against Spodoptera litura (F.) on Soybean. Economic losses due toinfestation by the soybean armyworm, Spodoptera litura can reach up to 100%. Some farmers often used insecticide to control thearmyworm. However, regular use of insecticide can cause several negative effects such as environmental pollution, residual toxicity,and health hazard for human. The objective of this research was to determine the larvicidal, antifeedant, and activities of cloveleaf oil (CLO) against the armyworm S. litura on soybean. The research was carried out at the plant pest control laboratory ofPoliteknik Pembangunan Pertanian Malang. Clove leaf oil was evaluated for its larvicidal and antifeedant activities against tenthird instar larvae of the armyworm. Completely randomized design was used with concentration levels of CLO as treatments.i.e. 0.4, 0.5, 0.67, 1.0, and 2.0% by volume. Profenofos 500 g L 0.1% and distilled water were include as control. Each treatment consisted of five replications. Mortality of the larvae and antifeedant activity were analyzed using analysis of variance, followed by probit analysis for calculating LC 50 and LT 50-1. The results showed that CLO at 2.0% concentration was the most effective with regard to larvicidal and antifeedant activities. The LC 50 of CLO was 0.09% with LT 24.6 hours. This study revealed that the environmentally friendly CLO can be used as an alternative to synthetic insecticide for control S. litura.

Global food security poses a significant challenge in meeting the needs of a rapidly growing population. Currently, producers rely on chemical pesticides to overcome pest-related problems in crop husbandry. However, the extensive use of synthetic molecules results in environmental pollution, resistance development, residual toxicity, pest recurrence and negative impacts on human and animal health. The expanding worldwide population has generated a substantial need for agricultural goods in terms of both quality and quantity, leading to a notable rise in the application of agricultural chemicals, including chemical pesticides, to combat insect pests. As a result, the use of entomopathogens for biological control has emerged as a prominent choice among these options. Currently, farmers are using microbial biopesticide solutions to counteract the negative effects of specific insects on crops. Microbes present a sustainable and adaptable solution that can effectively combat harmful pests without causing significant economic damage while simultaneously improving the health and productivity of plants. In 2020, biopesticides held a 6 % share in the global pesticide industry, with projections indicating a twofold increase to approximately 15 % by 2031. The purpose of this review was to highlight the widely accessible endophytic entomopathogens and explore their potential as a substitute for chemical pesticides. The primary goal of using endophytic entomopathogens is to maintain an optimal level of production, improve environmental well-being, reduce pesticide use and conserve natural resources. Moreover, research is now being conducted to investigate further potential characteristics, particularly concentrating on effective and rapidly spreading endophytic entomopathogens. This paper presents an overview of the mechanisms of action and the resistance they provide against herbivore insects, along with their respective benefits and limitations.

Controlling deltamethrin-resistant Rhipicephalus microplus with a phytoformulation of Annona muricata and Piper longum.

The over and repeated use of chemical bactericides to control plant bacterial diseases has resulted in unwanted effects, such as environmental pollution, residual toxicity, and resistance buildup in bacterial pathogens. Many previous studies have aimed to develop biological control agents to replace chemical bactericides. In this study, the antibacterial efficacy of the fermentation broth of Paenibacillus elgii JCK-5075 and its antibacterial compounds were evaluated against plant pathogenic bacteria, using both in vitro and in vivo bioassays. Pelgipeptins (PGPs) A, B, C, and D that were isolated from P. elgii JCK-5075 displayed broad-spectrum antibacterial activity against various plant pathogenic bacteria. The fermentation broth of P. elgii JCK-5075, at 5-fold dilution, effectively suppressed the development of tomato bacterial wilt, Kimchi cabbage soft rot, and red pepper bacterial leaf spot in pot experiments with control values of 81, 84, and 67%, respectively. PGP-A and C, at 200 μg/ml, were also found to markedly reduce the development of Kimchi cabbage bacterial soft rot by 75% and tomato bacterial wilt by 83%, respectively, and their disease control efficacy was comparable to that of oxolinic acid with control values of 81 and 85%, respectively. Additionally, the antibacterial activity of PGP-C was found to be directly correlated with membrane damage mechanisms. These results indicates that P. elgii JCK-5075 producing PGPs could be used as a biocontrol agent for the control of plant bacterial diseases. This is the first report on the in vitro and in vivo antibacterial activity of PGPs against bacterial plant pathogens.

The dust and ashes from the destruction of the World Trade Center in New York City on September 11, 2001, have developed dual and contrasting significance: valued as remains of loved ones and feared as toxic residue. Dust has long been associated with the evanescence of life—and more recently, with dangerous environmental exposures or toxicities. The desire for connection to human remains in the continuing work of mourning is put in tension with the need to avoid contamination. A process of sacralization is juxtaposed to identification of an environmental hazard. For the past twenty years, artists and scientists have offered multiple framings, often from contrary perspectives, on the meanings of the dust and ashes of 9/11. Drawing on a century of experiment and speculation, they have devised various means of staying close while keeping distant, of attachment and containment. That the remains of loved ones can now be refigured as risk factors seems a characteristically “modern” predicament. Such concerns about dust and ashes draw attention to contemporary regimes of perceivability and breathability, which are manifested also in atmospheric hazards of climate change and aerosolized viral transmission in pandemic disease—ecological regimes that are extending and reframing the scope of grievability.