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Glyphosate has limited short-term effects on commensal bacterial community composition in the gut environment due to sufficient aromatic amino acid levels
2018
Nielsen, Lene Nørby | Roager, Henrik M. | Casas, Mònica Escolà | Frandsen, Henrik L. | Gosewinkel, Ulrich | Bester, Kai | Licht, Tine Rask | Hendriksen, Niels Bohse | Bahl, Martin Iain
Recently, concerns have been raised that residues of glyphosate-based herbicides may interfere with the homeostasis of the intestinal bacterial community and thereby affect the health of humans or animals. The biochemical pathway for aromatic amino acid synthesis (Shikimate pathway), which is specifically inhibited by glyphosate, is shared by plants and numerous bacterial species. Several in vitro studies have shown that various groups of intestinal bacteria may be differently affected by glyphosate. Here, we present results from an animal exposure trial combining deep 16S rRNA gene sequencing of the bacterial community with liquid chromatography mass spectrometry (LC-MS) based metabolic profiling of aromatic amino acids and their downstream metabolites. We found that glyphosate as well as the commercial formulation Glyfonova®450 PLUS administered at up to fifty times the established European Acceptable Daily Intake (ADI = 0.5 mg/kg body weight) had very limited effects on bacterial community composition in Sprague Dawley rats during a two-week exposure trial. The effect of glyphosate on prototrophic bacterial growth was highly dependent on the availability of aromatic amino acids, suggesting that the observed limited effect on bacterial composition was due to the presence of sufficient amounts of aromatic amino acids in the intestinal environment. A strong correlation was observed between intestinal concentrations of glyphosate and intestinal pH, which may partly be explained by an observed reduction in acetic acid produced by the gut bacteria. We conclude that sufficient intestinal levels of aromatic amino acids provided by the diet alleviates the need for bacterial synthesis of aromatic amino acids and thus prevents an antimicrobial effect of glyphosate in vivo. It is however possible that the situation is different in cases of human malnutrition or in production animals.
Show more [+] Less [-]Removal of β-lactam antibiotics from pharmaceutical wastewaters using photo-Fenton process at near-neutral pH
2018
Giraldo-Aguirre, Ana L. | Serna-Galvis, Efraím A. | Erazo-Erazo, Edgar D. | Silva-Agredo, Javier | Giraldo-Ospina, Héctor | Flórez-Acosta, Oscar A. | Torres-Palma, Ricardo A.
In this work, the photo-Fenton process at near-neutral pH was applied for the removal of the β-lactam antibiotic oxacillin (OXA) in water using artificial and sunlight. Initially, the main variables of the process (Fe(II), H₂O₂, and light power) were optimized by a statistical factorial design (2³ with center points). The experimental design indicated that 90 μmol L⁻¹ of Fe(II), 10 mmol L⁻¹ of H₂O₂, and 30 W of power light were the favorable conditions for degradation of OXA at 203 μmol L⁻¹. In the photo-Fenton system, the H₂O₂ alone, UV-light/H₂O₂, and Fe(II)/H₂O₂ subsystems presented a significant participation on antibiotic removal. Moreover, based on the primary organic transformation products, a mechanism of OXA degradation was proposed. Under the favorable operational conditions, both the pollutant and the antimicrobial activity were eliminated after 50 min of process application. Although at 480 min of treatment, only 5% of mineralization was achieved, the level of biodegradability of the solutions increased from 0.08 to 0.98. Interestingly, the presence of pharmaceutical additives (glucose, isopropanol, and oxalic acid) had a moderate interference on the efficiency of the pollutant removal. Additionally, the treatment at pilot scale of the β-lactam antibiotic in a pharmaceutical complex matrix using solar radiation allowed the complete removal of the pollutant and its associated antimicrobial activity in a very short time period (5 min). These results evidenced the applicability of the photo-Fenton process to treat wastewaters from pharmaceutical industry loaded with β-lactam antibiotics at near neutral pH values efficiently.
Show more [+] Less [-]Ecotoxicological assessment of oil-based paint using three-dimensional multi-species bio-testing model: pre- and post-bioremediation analysis
2018
Phulpoto, Anwar Hussain | Qazi, Muneer Ahmed | Haq, Ihsan Ul | Phul, Abdul Rahman | Ahmed, Safia | Kanhar, Nisar Ahmed
The present study validates the oil-based paint bioremediation potential of Bacillus subtilis NAP1 for ecotoxicological assessment using a three-dimensional multi-species bio-testing model. The model included bioassays to determine phytotoxic effect, cytotoxic effect, and antimicrobial effect of oil-based paint. Additionally, the antioxidant activity of pre- and post-bioremediation samples was also detected to confirm its detoxification. Although, the pre-bioremediation samples of oil-based paint displayed significant toxicity against all the life forms. However, post-bioremediation, the cytotoxic effect against Artemia salina revealed substantial detoxification of oil-based paint with LD₅₀ of 121 μl ml⁻¹ (without glucose) and > 400 μl ml⁻¹ (with glucose). Similarly, the reduction in toxicity against Raphanus raphanistrum seeds germination (%FG = 98 to 100%) was also evident of successful detoxification under experimental conditions. Moreover, the toxicity against test bacterial strains and fungal strains was completely removed after bioremediation. In addition, the post-bioremediation samples showed reduced antioxidant activities (% scavenging = 23.5 ± 0.35 and 28.9 ± 2.7) without and with glucose, respectively. Convincingly, the present multi-species bio-testing model in addition to antioxidant studies could be suggested as a validation tool for bioremediation experiments, especially for middle and low-income countries. Graphical abstract ᅟ
Show more [+] Less [-]Facile and environmental benign in situ synthesis of silver nanoparticles for multifunctionalization of wool fibers
2018
Mowafi, Salwa | Kafafy, Hany | Arafa, Amany | Haggag, Karima | Rehan, Mohamed
In this manuscript, we report the simple method to multifunctional wool fiber surfaces. The multifunctional wool fibers were devised with brilliant coloration, antimicrobial activity, and UV-protection property. These multifunctional properties were progressed by in situ assemble of silver nanoparticles (Ag NPs) into the wool fiber surface using green cleaner one-pot route. The proteins existing in the wool fibers acted being a redox active bio-template, facilitating the reduction of Ag⁺ to Ag⁰, with simultaneous binding of the produced Ag NPs both on the surface and within the center of the wool fibers. The entire results showed that the Ag NP in situ-incorporated wool fibers can be used as colorant wool fibers effectively, and these colored fibers also exhibit an improvement for multi-functionality properties.
Show more [+] Less [-]Antimicrobial, cytotoxic and antioxidative evaluation of natural deep eutectic solvents
2018
Radošević, Kristina | Čanak, Iva | Panić, Manuela | Markov, Ksenija | Bubalo, MarinaCvjetko | Frece, Jadranka | Srček, VišnjaGaurina | Redovniković, IvanaRadojčić
Natural deep eutectic solvents (NADES) are a new generation of green solvents. They are mixtures of two or three compounds such as choline chloride as a cationic salt and alcohols, acids, amides, amines or sugars as hydrogen-bond donors. Although the majority of NADES’ components are of natural origin and therefore NADES are often presumed to be non-toxic, the evaluation of their toxicity and biodegradability must accompany the research on their synthesis and application. Therefore, the aim of this work was to investigate the effect of ten synthesised NADES towards bacteria (i.e., Escherichia coli, Proteus mirabilis, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus), yeast (i.e., Candida albicans) and human cell lines (i.e., HeLa, MCF-7 and HEK293T). In addition, oxygen radical absorbance capacity (ORAC) method was used to determine the antioxidative activity of the tested NADES. Differences in toxicity response between microorganisms and cell lines were observed, and only NADES that contained organic acid showed toxicity towards the test systems. Furthermore, the NADES containing compounds that possess antioxidative activity also showed antioxidative activity. However, research whose primary purpose is the synthesis and application of NADES must be followed by an evaluation of their biological properties (e.g., antimicrobial activity, toxicity towards animal cells and antioxidative or other biological activity) to find the solvent with the best profile for wider industrial applications.
Show more [+] Less [-]Environmental levels of triclosan and male fertility
2018
Triclosan is a synthetic chemical with broad antimicrobial activity that has been used extensively in consumer products, including personal care products, textiles, and plastic kitchenware, although the exposure which is widespread evidence from human studies is scarce. Our study aims to investigate the relationship between triclosan exposure and male fertility. Triclosan (TCS) urinary concentrations were measured using gas chromatography coupled with tandem mass spectrometry in 315 men recruited from a male reproductive health clinic with normal sperm concentration (≥ 15 mln/ml) (WHO 2010) under 45 years of age. Participants were interviewed and provided a semen sample. TCS was detected in 84.13% of urine samples, with a median concentration of 2.83 μg/l (2.57 μg/g creatinine). A multiple linear regression analysis showed a positive association between the urinary concentrations of triclosan 50th–75th percentile and ≥ 50 percentile and percentage of sperm with abnormal morphology (p = 0.016 and p = 0.002, respectively). The study provides evidence that exposure to triclosan is associated with poorer semen quality. Future studies are needed to confirm these findings.
Show more [+] Less [-]Using Citrus aurantifolia essential oil for the potential biocontrol of Colocasia esculenta (taro) leaf blight caused by Phytophthora colocasiae
2018
Tchameni, Séverin Nguemezi | Mbiakeu, Staelle Njamou | Sameza, Modeste Lambert | Jazet, Pierre Michel Dongmo | Tchoumbougnang, François
The aim of this work was to evaluate the antimicrobial activities of leaves and epicarp of Citrus aurantifolia essential oil against Phytophthora colocasiae, the causative agent of taro leaf blight. Oils were extracted by hydrodistillation, and their chemical composition was determined by gas chromatography and gas chromatography coupled with mass spectrometry. Antimicrobial activities of oils were tested in vitro against mycelium growth and sporangium production. In situ tests were done on healthy taro leaves, and the necrosis symptoms were evaluated. Results showed that the essential oil extraction yields from leaves and epicarp were 0.61 and 0.36%, respectively. Limonene (48.96%), bornyl acetate (14.18%), geraniol (10.53%), geranial (3.93%), and myrcene (3.14%) were the main components in leaf oil, while limonene (59.09%), cis-hydrate sabinene (7.53%), geranial (5.61%), myrtenol (5.02%), and terpinen-4-ol (3.48%) were the main components in epicarp oil. Both oils exhibited antimicrobial activities with total inhibition of the mycelium growth at 500 and 900 ppm for leaf and epicarp, respectively. The highest inhibitory concentration of sporangium production was 400 (72.84%) and 800 ppm (80.65%) for leaf and epicarp oil, respectively. For the standard fungicide (metalaxyl), the total inhibition value of mycelial growth and sporangium production was 750 ppm. In situ tests showed that, at 5000 ppm, total inhibition (100%) was obtained for a preventive test, while 50% of the inhibition was observed for a curative test when leaf oil was applied. When epicarp essential oil was applied at 5000 ppm, 47.5 and 16.66% of the reduction of leaf necrosis were observed for the preventive and curative test, respectively. There were positive correlations between both the oil concentration and the reduction of necrosis caused by P. colocasiae. These findings suggest that the C. aurantifolia essential oil could serve as an eco-friendly biocontrol for the management of taro leaf blight.
Show more [+] Less [-]Brevibacillus laterosporus isolated from the digestive tract of honeybees has high antimicrobial activity and promotes growth and productivity of honeybee’s colonies
2018
Khaled, JamalM. | Al-Mekhlafi, FahdA. | Mothana, RamziA. | Alharbi, NaiyfS. | Alzaharni, KhalidE. | Sharafaddin, AnwarH. | Kadaikunnan, Shine | Alobaidi, AhmedS. | Bayaqoob, NoofalI. | Govindarajan, Marimuthu | Benelli, Giovanni
The development of novel antimicrobial drugs, as well as the discovery of novel compounds able to promote honeybee’s growth, represents major challenges for modern entomology. The main aim of this study was to investigate whether Brevibacillus laterosporus isolated from the digestive tract of Saudi honeybees, Apis mellifera, was able to stimulate colony strength parameters of honeybees and to evaluate its ability to produce antimicrobial agents. Honeybees were collected in Dirab, Riyadh Region, Saudi Arabia, and microorganisms were isolated and identified by 16S ribosomal RNA analysis. Microscopic identification of the microorganism in its native state was facilitated by atomic force microscopy at high-resolution imaging. Active biological compounds were produced by submerged fermentation with B. laterosporus. The fermented broth was subjected to extraction and purification, and then semi-pure compounds were analyzed by gas chromatography–mass spectrometry. The effectiveness of the crude extract and semi-pure compounds as antimicrobial agents was evaluated by susceptibility assays. More than 22% of the microorganisms isolated from the digestive tract of healthy honeybees have been identified as B. laterosporus, this kind of species has a unique shape and morphological structure. The cyclic dipeptide cyclo(Leu-Pro) produced by B. laterosporus showed biological activity against several pathogenic microorganisms. Furthermore, the total counts of workers, closed brood, and open brood, as well as the production of bee pollen and honey, were better in honeybees treated with a B. laterosporus suspension. The data indicated that the B. laterosporus strain isolated from a healthy honeybee might be a novel probiotic and a producer of important biological compounds.
Show more [+] Less [-]Correction to: Brevibacillus laterosporus isolated from the digestive tract of honeybees has high antimicrobial activity and promotes growth and productivity of honeybee’s colonies
2018
Khaled, Jamal M. | Al-Mekhlafi, Fahd A. | Mothana, Ramzi A. | Alharbi, Naiyf S. | Alzaharni, Khalid E. | Sharafaddin, Anwar H. | Kadaikunnan, Shine | Alobaidi, Ahmed S. | Bayaqoob, Noofal I. | Govindarajan, Marimuthu | Benelli, Giovanni
The original publication of this paper contains a mistake. The correct affiliation no. 3 is shown in this paper.
Show more [+] Less [-]Toxicity against Drosophila melanogaster and antiedematogenic and antimicrobial activities of Alternanthera brasiliana (L.) Kuntze (Amaranthaceae)
2018
Coutinho, HenriqueDouglas Melo | de Morais Oliveira-Tintino, CíceraDatiane | Tintino, SauloRelison | Pereira, RaimundoLuiz Silva | de Freitas, ThiagoSampaio | da Silva, MariaArlene Pessoa | Franco, JefersonLuis | da Cunha, FranciscoAssis Bezerra | da Costa, JoséGalberto Martins | de Menezes, IrwinRose Alencar | Boligon, AlineAugusti | da Rocha, JoãoBatista Teixeira | Rocha, MariaIvaneide | dos Santos, JoycyFrancely Sampaio
Bioactive phytocompounds are studied by several bioactivities demonstrated, as their cytotoxic effects. The aim of this work was to evaluate the phytochemical profile, the toxic effect using the Drosophila melanogaster animal model and the anti-inflammatory and antimicrobial effect of the Alternanthera brasiliana (EEAB) ethanol extract. The phytochemical profile was performed using HPLC. The cytotoxic effect was evaluated in vivo using D. melanogaster. The anti-inflammatory effect was determined by neurogenic and antiedematogenic assays, and the antimicrobial activity was assayed using a microdilution method to determine the minimum inhibitory concentration (MIC) of the EEAB alone and in association with antibiotics. The main compound identified on the EEAB was luteolin (1.93%). Its cytotoxic effect was demonstrated after 24 h in the concentrations of 10, 20 and 40 mg/mL. The extract demonstrated an antiedematogenic effect, with a reduction of the edema between 35.57 and 64.17%. The MIC of the extract was ≥1.024 μg/mL, thus being considered clinically irrelevant. However, when the EEAB was associated with gentamicin, a synergism against all bacterial strains assayed was observed: Staphylococcus aureus (SA10), Escherichia coli (EC06) and Pseudomonas aeruginosa (PA24). Due to these results, the EEAB demonstrated a low toxicity in vivo and anti-inflammatory and synergistic activities. These are promising results, mainly against microbial pathogens, and the compounds identified can be a source of carbon backbones for the discovery and creation of new drugs.
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