Detoxification Parameters Research Articles

Nutrition Rehabilitation in Oncopathology: Opportunities and Prospects

Nutritional corrective support is an integral component of rehabilitation programs in the perioperative period for oncological pathology. The aim of this study was to evaluate the effectiveness of including remaxol in the rehabilitation treatment regimen for gastroenterological cancer patients. Material and methods. The treatment results of 42 patients with gastric outlet tumors and small intestine tumors were retrospectively analyzed. Remaxol was included in the adjuvant therapy for patients in the main (I, N=22) group: intravenously 400 ml at a rate of 40–80 drops/min (2–4 ml/min) once a day for 10 days. Patients in the comparison group (II, N= 20) received traditional nutritional therapy. The study used both traditional clinical diagnostic methods and methods for assessing the risks of nutritional deficiency and the rehabilitation potential of the body, its adaptive capabilities, and disease prognosis. Results. All patients showed signs of severe nutritional deficiency, endotoxemia, intoxication, and hepatotoxicity. Liver detoxification parameters were better in patients who received remaxol as an adjuvant therapy than in the comparison group. Conclusions. Cancer patients with a high nutritional risk and moderate to high nutritional deficiency are at a higher risk of developing toxic complications requiring adjuvant therapy. The inclusion of remaxol in adjuvant therapy reduced the severity of hepatotoxic reactions in these patients. The data obtained made it possible to recommend its inclusion in treatment regimens for patients with this pathology.

Detoxification of produced water from oil & gas industries using piperazine immobilized Green Fe nanoparticles

The biggest waste stream in the oil and gas sector is produced water. It is made up of both organic and inorganic wastes, both of which, if untreated, are extremely harmful to the environment. This study aims to use Fe-based nanoparticles in an attempt to detoxify produced water. Fe nanoparticles were prepared using green synthesis approach, and their stability was increased by piperazine immobilisation in a chlorinated environment. Experiments on detoxification were carried out under various circumstances in order to determine the effectiveness of detoxification. Variations in the feasible detoxification parameters, including the, the amount of Green Fe nanoparticles immobilised by piperazine, the pH of the reaction medium, the duration of the detoxification process were found to improve the detoxification efficiency. Using Ultra-violet visual ray spectroscopy and Fourier Transform Infrared Spectroscopy, the properties of the prepared Fe naoparticles were analyzed. Chemical and microstructural properties of the nanoparticles were studied using X-Ray Diffraction Spectroscopy, X-ray photoelectron spectroscopy (XPS), Field Emission-Scanning Electron Microscopy and Transmission Electron Microscopy. Detoxification experiments conducted in photocatalytic environment exhibited detoxification efficiency as high as 89.3 %.

The ameliorative effects of Nigella sativa, thymoquinone, and bentonite against aflatoxicosis in broilers via AFAR and Nrf2 signalling pathways, and down-regulation of caspase-3

ABSTRACT 1. Aflatoxins (AFs) are metabolites which especially have toxic effects on proteins, and are detoxified by the aflatoxin-B1 aldehyde reductase (AFAR) pathway. In this pathway, the aldo-keto reductase family 7, member A2 (AKR7A2) enzyme, which is controlled by nucleic-related erythroid factor 2 (Nrf2), plays an active role. However, data on the efficacy of this critical pathway in broilers is limited. 2. The aim of the following study was to investigate the changes in the expression levels of AKR7A2, Nrf2, and caspase-3, and the effects of Nigella sativa seeds (NS), thymoquinone (TMQ), and bentonite (BNT) in broilers exposed to AFs. 3. One-hundred broilers were divided into ten groups (control (CNT); AF; NS; TMQ; BNT; AF+TMQ; AF+NS; AF+BNT; AF+BNT+NS; AF+BNT+TMQ) and fed for 28 d. AF, TMQ, NS and BNT were added to diets at levels of 2 mg/kg, 300 mg/kg, 50 g/kg and 10 g/kg respectively. 4. The addition of AF to the diet decreased AKR7A2 and Nrf2 levels dramatically, but increased caspase-3 (P < 0.01). TMQ, NS and BNT additions to the diet eliminated all negative effects caused by AF (P < 0.01); and AKR7A2 and Nrf2 were further raised in TMQ and NS groups when compared to the control group. TMQ and NS showed a positive effect on detoxification parameters when given together with BNT. 5. Supplementation with NS and TMQ enhanced AF detoxification via the AFAR pathway, by increasing AKR7A2 and Nrf2 levels, in addition to reducing hepatocyte apoptosis.

Development of Cholesterol-Lowering and Detox Formulations Using Bentonite and Herbal Ingredients.

Detoxification enzymes involved in human metabolism works to minimize the potential xenobiotic-induced damage constantly. Studies have revealed that toxin accumulation plays an important role in the etiology of cardiovascular disease. This study has been designed to provide evidence of medicinal use of bentonite, turmeric (Curcuma longa L.), grape (Vitis vinifera L.) seed, flaxseed (Linum usitatissimum L.), and psyllium (Plantago ovata L.) as detoxification and cholesterol-lowering agents using a hypercholesterolemic model in mice. The potential hypocholesterolemic effects and detoxification ability of these ingredients were evaluated at the same time: Total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, glucose, aspartate aminotransferase, alanine aminotransferase, malondialdehyde, plasma total antioxidant activity, nitric acid, leptin levels and glutathione, glutathione peroxidase, lipid peroxidation, superoxide dismutase and catalase values were measured. It was determined that GBTF group (grape seed extract, bentonite, turmeric, and flaxseed), GBTP group (grape seed extract, bentonite, turmeric, and psyllium), and GBT group (grape seed extract, bentonite, and turmeric) of the tested materials decreased the serum total cholesterol concentration by 64.8, 57.5, and 48.9%, respectively, in mice fed a high cholesterol diet. In addition, it was determined that some detoxification parameters such as superoxide dismutase, catalase, glutathione, and glutathione peroxidase were statistically significantly reversed in GBTF, GBTP, and GBT groups. Flaxseed, psyllium, and bentonite clay did not show significant effects in reducing total cholesterol; however, GBTF, GBTP, and GBT groups interventions had a significant effect in reducing total cholesterol levels. Moreover, it was observed that adding flaxseed or psyllium to the GBT group increased the cholesterol-lowering effect. Therefore, it can be thought that this significant effect is due to the synergistic effect of the raw materials. When the results obtained were evaluated, it was seen that the cholesterol-lowering and detoxification effects of the combinations were higher than from the effect of natural material used alone. As a result, combinations of some of these ingredients have a positive effect on reducing the risk of cardiovascular disease.

Optimization of activated charcoal detoxification and concentration of chestnut shell hydrolysate for xylitol production.

To increase xylose concentration of the chestnut shell hemicellulosic hydrolysate with an acceptable phenolic compound level in order to enhance xylitol production by Candida tropicalis M43. The xylose concentration and total phenolic compound concentration of the hydrolysate were obtained as 33.68g/L and 77.38mg gallic acid equivalent/L, respectively by optimization of detoxification parameters and concentration level (60°C, 115min contact time, 5.942% (w/v) dosage of activated charcoal, 120 strokes/min shaking rate and 0.2 volume ratio). Xylitol production was achieved in the hydrolysate by using Candida tropicalis M43. The maximum xylitol concentration was 6.30g/L and productivity, yield and percentage of substrate conversion were calculated as 0.11g/L h, 19.13% and 97.79%, respectively. In addition, the chestnut shell hydrolysate fortified with xylose and the maximum xylitol concentration increased to 18.08g/L in the hydrolysate-based medium containing 80g/L xylose. Optimizing detoxification conditions with concentration level was found to be useful for enhancing xylitol production. In addition, fortification of the hydrolysate caused a three fold increase in maximum xylitol concentration.

Kinetics and mathematics modeling of ochratoxin a detoxification in maize dough by Lacticaseibacillus casei subs. casei subjected to continuous and pulsed ultrasound

The Lacticaseibacillus casei subsp. casei growth and ochratoxin A removal during fermentation of maize dough were mathematically modeled using the Baranyi and statistical models of Weibull and modified Gompertz models, respectively. The effect of important detoxification parameters including temperature level (35 and 37°C), sonication duration (0, 5, 10 and 15 min) as well as continuous/pulsed ultrasound treatment was investigated. According to the obtained results, the utilization of the pulsed sonication can improve the performance of the conducted treatment in comparison to the continuous case for 15 min duration of sonication. However, for lower periods of sonication (i.e., 5 and 10 min), the continuous sonication was proved to be more efficient in detoxification process. It was observed 2°C temperature increase lead to an average 4.33 µg/kg reduction of the Ochratoxin A after 48 hr fermentation from the sonication. Practical applications Microbial decontamination may give probable elimination of mycotoxins in food products under mild conditions, therefore preventive important losses in the quality of food products. Biological degradation of ochratoxin A under pulsed and continuous ultrasound was modeled. It was observed 2°C temperature increase lead to an average 4.33 µg/kg reduction of the Ochratoxin A after 48 hr fermentation from the sonication. Therefore, biological detoxification under optimal ultrasound treatment is an effective and rapid way to degrade ochratoxin A in maize dough.

Ветеринарные аспекты хозяйственно-полезных качеств холмогорского скота

The paper reflects the current state of the Kholmogorsky cattle of the Komi Republic and its economic and useful fea-tures. Based on re¬search conducted in 2018-2019, it was found that purebred Kholmogorsky cattle have a longer period of economic use (by 1.0...2.5 calving) compared to Holstein genotypes, are less likely to be removed from the herd due to diseases, and have a high lifetime productivity. Morphological and detoxification parameters of blood in these animals are characterized by a pronounced compensatory reaction. Purebred Kholmogorsky cattle require less veterinary care, are not demanding to fodder and are a more promising breed for breeding in small and individual farms in the North of Russia.

Co-administration of zinc for treating and preventing arsenism in common carp Cyprinus carpio: An alternative to avoid physiological and cellular damages

Arsenic (As) contamination in water bodies has adverse effects on aquatic organisms. Zinc (Zn), as an important enzyme cofactor and efficient reactive oxygen species scavenger, plays an indispensable role in cellular homeostasis and biological functions. However, there has been less investigation on AsZn interaction in common carp (Cyprinus carpio). We hypothesize that Zn is a candidate for the treatment and prevention of arsenism. In general, feed efficiency, growth performance and organ indices did not significantly differ between the As or/and Zn group and the control groups (p > 0.05). However, arsenite significantly altered the intestinal morphological features and suppressed intestinal tight junction proteins (claudins, occluding, and zonula occludens) as indicated by mRNA and protein levels. Moreover, oxidative stress (malondialdehyde and organic 8-hydroxy-2-deoxyguanosine), inflammatory (nuclear factor kappa-B and pro-inflammatory cytokines) and detoxification parameters (metallothionein) in intestine and liver increased following arsenite exposure (p < 0.05), concomitant with innate immunity suppression (C4 and IgM; p < 0.01). These anomalies led to abnormal lipid metabolism (SREBP-1c pathway; p < 0.01) and endoplasmic reticulum stress (PERK-eIF2α, IRE1α and ATF6; p < 0.01). Overall, As impaired general physiological and cellular functions, and compromised the immune system of carp. Zn2+ restored these alterations, as evidenced by the reduction in inflammation and endoplasmic reticulum stress via the activation of the antioxidant system. Thus, Zn supplementation can be used to treat and prevent arsenism; it is a useful alternative to prevent physiological and cellular damage in the inland culture of carp.

Biomarker considerations in monitoring petrogenic pollution using the mussel Mytilus galloprovincialis.

Mussels are worldwide bioindicators in pollution monitoring since they fulfil the requirements for being good sentinels. However, some methodological concerns arise in the use of particular biomarkers, particularly those displaying low enzymatic rates and/or limited responsiveness to chemicals and biological-related variability. In the present study, the suitability of oxidative stress and detoxification parameters when using mussels as sentinels of polycyclic aromatic hydrocarbon (PAH) pollution is addressed. Present results show that the S9 subcellular fraction of the digestive gland in mussels is an adequate and convenient matrix where to measure most pollution-related biomarkers. Furthermore, this work constitutes the first evidence of the potential suitability of using particular carboxylesterase (CE) activities in determining PAHs exposure in mussels. This fact could imply the replacement of more controversial cytochrome P450 components (phase I oxidation), which are only measurable in microsomal fractions, by CEs (measured in S9 fractions) as good alternatives for phase I reactions in PAH-exposed mussels. Some methodological considerations, such as the need of including commercial purified proteins in biomarker determinations for quality assurance, are evaluated.

Chromium slag detoxification by carbon monoxide off-gases and optimization of detoxification parameters by Box–Behnken design

This study explores the feasibility and advantages of chromium slag (CS) detoxification by carbon monoxide (CO) off-gases. A chromate plant in an industrial park was surveyed to determine the pollution distribution and pathways. Based on the plant’s layout, the technology of CS dry-detoxification by CO off-gases was proposed. The response surface methodology and Box–Behnken design were adopted in bench-scale experiments to analyze and optimize the factors that influence the reaction. The effect of H2, which is the major impurity in CO off-gases, was studied using simulated off-gases. The results indicated that CO could effectively reduce Cr(VI) below 400 °C, and a small amount of H2 in the off-gases significantly promoted the detoxification effect. The Box–Behnken design experiment showed that temperature was the key factor in the reduction process. Simulated polynomial functions were proved to be effective in optimizing the technological parameters and predicting the detoxification effects.

Effect of long-term cadmium and copper intoxication on the efficiency of ampullate silk glands in false black widow Steatoda grossa (Theridiidae) spiders

The aim of the study was to compare cellular effects of xenobiotic cadmium and biogenic copper in ampullate silk glands of false black widow Steatoda grossa spider after long-term exposure via ingestion under laboratory conditions. Both the level of selected detoxification parameters (glutathione S-transferase, catalase, and the level of total antioxidant capacity) and degree of genotoxic changes (comet assay) were determined in the silk glands. Additionally the contents of selected amino acids (L-Ala, L-Pro, L-His, L-Phe, DL-Ile, and DL-Asn) in the hunting webs produced by spiders of this species were assessed. The ability of S. grossa females to accumulate cadmium was higher than that for copper. Long-term exposure of spiders to copper did not change the level of detoxification parameters, and the level of DNA damage in the cells of ampullate silk glands was also low. Cadmium had a stronger prooxidative and genotoxic effect than copper in the cells of the analyzed silk glands. However, regardless of the type of metal used, no significant changes in the level of amino acids in silk were found. The obtained results confirmed the effectiveness of metal neutralization mechanisms in the body of the studied spider species, which results in the protection of the function of ampullate silk glands.

Application of a series of biomarkers in Scallop Chlamys farreri to assess the toxic effects after exposure to a priority hazardous and noxious substance (HNS)—Acrylonitrile

The antioxidant enzymes and detoxification parameters responses of the scallop Chlamys farreri to different degree of acrylonitrile (AN) were investigated. Accordingly, the median lethal concentration (LC50) at 96 h was 98.5 mg/L AN. Results from chronic toxicity test demonstrated that superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were stimulated in the highest two doses of AN (2.0 and 5.0 mg/L), but significantly inhibited in the highest concentration (5.0 mg/L) at the end of the exposure. The levels of DNA strand breaks, lipid peroxidation (LPO) and protein carbonyl (PC) contents showed damage effects exposed AN at the highest two doses. Additionally, AN significantly induced the enzymatic activity of glutathione-s-transferase (GST), related mRNA expression levels of P-glycoprotein (P-gp) and GST-pi; and no significant changes were found on CYP1A1 mRNA expression and ethoxyresorufin O-deethylase (EROD) activity. Our results indicated that P-gp and GST-pi mRNA expression in digestive glands of the scallop C. farreri may potentially be used in ecological risk assessment of hazardous and noxious substances (HNS) contamination of marine.

Beneficial Gut Effect of a Symbiotic-Probiotic Regimen in Healthy Stressed Individuals: Effectiveness on Permeability, Microbiota and Detoxification Parameters

The aim of the present study was to test either a previously studied symbiotic, a novel probiotic mixture or a sequence symbiotic-probiotic schedule in beneficially affecting gut health parameters in otherwise healthy stressed individuals. This was a multicenter randomized study with no gender selection. A total of hundred-twenty individuals aged between 38 and 62 years were recruited for this study. Patients were selected to have an overall positive attitude towards their personal life and work but reporting high-demanding job activity regarded as stressful. Three age and gender-matched groups (40 pts each) were considered: A) given a symbiotic 10 ml t.i.d. for 5 months; B) given 1 tab t.i.d of P3T/J (a probiotic mixture) for 5 months and C) given the symbiotic 10 ml t.i.d. for 1 month and then shifted to 1 tab t.i.d of probiotic mixture for 4 months. A forth group (group D) of 20 healthy, stressed individuals coming from a prior study, supplemented a marine PUFA extract served as treatment control (a sturgeon-based fish collagen, Caviarlieri, Swiss cap packaging, Switzerland). As compared to baseline and all other groups, group C showed a significant decrease of morning salivary cortisol at awakening. When plotting these values against the STAI scores, it appeared a significant correlation (r:0.66, p B). Values of serum zonulin showed a wide scattering in all groups and by clustering those individuals, who were engaged in regular moderateintense physical activity, the baseline concentration of zonulin was higher as compared to the rest of the population and it occurred a remarkably lower level of zonulin with C schedule. Fecal parameters in B and C group showed a statistically significant reduction of β-glucuronidase at 2 months (p<0.05) while only group A and C maintained such status also at 5 months observation. As for fecal level of nitroreductase, this was beneficially reduced by B treatment during all the study period. Besides treatment A, also regimen C at 5 months showed a significant reduction of this parameter. Unlike group D, all the other three groups showed a significantly lower level of p-cresol at either 2 or 5 months observation with group C yielding the absolute lowest urinary concentration but only at 2 months. The subgroup in each treatment schedule group showed a significant increase of the Bacteriodetes/Firmicutes ratio which was normalized by B and C treatment. Either A, B and C regimes brought about a significant eubiosis modification of gut flora.

Biochemical approaches to assess oxidative stress induced by exposure to natural and synthetic dyes in early life stages in zebrafish

ABSTRACT Zebrafish early life stages were found to be sensitive to several synthetic dyes widely used in industries. However, as environmental concentrations of such contaminants are often at sublethal levels, more sensitive methods are required to determine early-warning adverse consequences. The aim of this study was to utilize a multibiomarker approach to examine underlying oxidative stress mechanisms triggered by sublethal concentrations of synthetic azo dye Basic Red 51 (BR51), the natural dye erythrostominone (ERY), and its light-degraded product using zebrafish embryos. Biochemical biomarkers included parameters of detoxification and markers of antioxidant system, as well as oxidative damage. Results showed pro-oxidant mechanisms attributed to BR51 and ERY as evidenced by increased glutathione S-transferase (GST) activity, a phase II detoxification enzyme related to reactive oxygen species detoxification. BR51 also elevated total glutathione (GSH+GSSG) levels and catalase activity. However, both dyes induced oxidative damage as evidenced by elevated lipid peroxidation content. In contrast, when the natural dye was photodegraded, no marked effects were observed for all biomarkers assessed. Data indicate that such dyes are pro-oxidants at sublethal concentrations, predominantly involving GSH and/or related enzymes pathway.

A comprehensive evaluation of the environmental quality of a coastal lagoon (Ravenna, Italy): Integrating chemical and physiological analyses in mussels as a biomonitoring strategy

This study aimed at evaluating the environmental quality of a coastal lagoon (Pialassa Piomboni, NW-Adriatic, Italy) by combining analyses of biomarkers of environmental stress and bioaccumulation of contaminants in marine mussels (Mytilus galloprovincialis) transplanted for 28days to six selected sites. Assessed biomarkers encompassed lysosomal endpoints, oxidative stress and detoxification parameters, specific responses to metals, neuro- and genotoxic substances; chemical analyses focused on PAHs, metals, pesticide and pharmaceuticals. Results showed up to a 67-fold bioaccumulation of 4- to 6-ring PAHs, including pyrene, fluoranthene, chrysene and benzo(ghi)perylene in transplanted mussels compared to reference conditions (T0). A 10-fold increase of Fe, Cr and Mn was observed, while pesticides and pharmaceuticals were not or slightly detected. The onset of a significant (p<0.05) general stress syndrome occurred in exposed mussels, as outlined by a 50–57.7% decrease in haemocytes lysosomal membrane stability and an increased lysosomal volume (22.6–26.9%) and neutral lipid storage (18.9–48.8%) observed in digestive gland. Data also revealed a diffuse lipofuscin accumulation (86.5–139.3%; p<0.05) in digestive gland, occasionally associated to a catalase activity inhibition in gill, indicating an increased vulnerability toward pro-oxidant factors. Higher levels of primary DNA damage (258%; p<0.05) and PAH accumulation were found in mussels exposed along the eastern shoreline, hosting a petrochemical settlement. Bioaccumulated metals showed a positive correlation with increased metallothionein content (85–208%; p<0.05) observed in mussels from most sites. Overall, the use of physiological and chemical analyses detected chronic alterations of the mussel health status induced by specific toxicological pathways, proving a suitable approach in the framework of biomonitoring programs of coastal lagoons.

The use of juvenile Solea solea as sentinel in the marine platform of the Ebre Delta: in vitro interaction of emerging contaminants with the liver detoxification system.

Juveniles of Solea solea were sampled during the spring season in three consecutive years at a marine site by the mouth of the Ebre river. The aim was to assess if the extractive works from the toxic load upstream the river could be reflected on the health status of the fish living at the immediate sea. The biomarkers selected for the in vivo field study are commonly used as indicators of chemical exposures. They include activities of energy metabolism: lactate dehydrogenase (LDH) and citrate synthase (CS); neurotoxicity: cholinesterases (ChE); xenobiotic metabolism: cytochrome P450 (CYP)-dependent: EROD and BFCOD, carboxylesterase (CbE), glutathione S-transferase (GST) and uridine diphosphate glucuronyltransferase (UDPGT); and oxidative stress parameters such as catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPX) as well as levels of lipid peroxidation (LPO). These biomarkers were mostly analysed in liver but also in gills and muscle depending on their particular tissue distribution and role. A complementary in vitro approach was also sought to see the capacity of common emerging contaminants (pharmaceuticals and personal care products; PPCPs) to interact with the liver microsomal detoxification system of the fish (EROD, BFCOD and CbE activities). The results indicated that in fish sampled in 2015 there was an enhancement in detoxification parameters (EROD, BFCOD and gill GR), muscular ChEs and gill CS, but a decrease in CbE activity and a marked oxidative stress situation (increased LPO and decreased CAT activity). Also, 4 out of the 10 PPCPs tested in vitro were able to interact with the CYP3A4 (BFCOD) enzymatic system while the lipid regulators simvastatin and fenofibrate inhibited CbE activity, as it occurs in higher vertebrates. The in vivo results support the use of a multibiomarker approach when assessing the disturbances due to chemical exposures, not only spatially but also over time, once the influence of other variables has been taken into consideration. The in vitro results highlight the importance of the CYP3A4 and CbE pathway in pharmaceutical metabolism, also in fish.

A Novel Mesophilic Anaerobic Digestion System for Biogas Production and In Situ Methane Enrichment from Coconut Shell Pyroligneous

A novel mesophilic anaerobic digestion process with detoxification-treated coconut shell pyroligneous was established, exhibiting an effective advantage in biogas production. The pyroligneous collected contained 166.2gl(-1) acetic acid, indicating great potential for biogas production. Detoxification was an effective way of simultaneously enriching biodegradable ingredients and removing inhibitors (mainly as phenols and organic acids) for digestion process. The digestion process lasted 96h and fermentation characteristics (chemical oxygen demand (COD) removal ratio, volatile fatty acid (VFA) consumptions, pH, total gas, methane yield, and phenol removal efficiency) were measured. The experiments successfully explored the optimum detoxification parameters, oxidized with 10% H2O2 followed by overliming, and demonstrated 89.3% COD removal, 91.4% methane content, 0.305 LCH4/g COD removed CH4 yield, and 88.81% phenol removal ratio. This study provided clues to overcome the negative effects of inhibitors in pyroligneous on biogas production. The findings could contribute to significant process in detoxified pretreatment of pyroligneous and develop an economically feasible technology for treating pyroligneous after producing charcoal.

Радиолитическое превращение природных токсинов в загрязненных растительных продуктах и водных растворах

The kinetic regularities of radiolytic transformation of natural toxins in their oxygen-containing water solutions are studied. Mechanisms of these processes are described in detail. Conditions developing the chain reactions, optimum parameters of detoxification of cereals, fruits and granulated forages are determined. The speed of radiolytic transformations of natural toxins increases with increasing of concentration of oxygen in water solutions and humidity in cereals, fruits and forages (amount of the dissolved oxygen in "free" water of a growing product).

VOF modeling and experimental validation of ozonation reactive flow under high ozone concentration in three-phase reactors for environment protection

In the realm of multiphase reaction engineering, the dynamic behavior of an ozonation bubble column reactor was comprehensively investigated under high ozone concentration (30–90g/Nm3) by means of a volume-of-fluid (VOF) model embedding the transport phenomena and the detoxification parameters. First, the CFD framework was validated in terms of hydrodynamic data to gather novel insights on the bubbly flow in three-phase reactors for environment protection. The numerical computations highlighted that both profiles for the bubble velocity, detachment time and diameter of ozone bubbles handled agreeably well with the experimental data. Second, the evolvement of bubble diameter when increasing the superficial gas/liquid velocity under different surface tension/viscosity conditions was investigated throughout various hydrodynamic flow regimes. According to the VOF simulation results, the detachment of ozone bubbles was more prominent at high interaction regimes when the bubble column was operated under high superficial liquid velocities, which correspondingly controlled the time-averaged bubble diameter. Afterwards, the VOF model was experimentally validated for the ozonation of phenol-like compounds under low and high interaction regimes reinforcing how the bubbly phenomena dictate the overall bubble column reactor performance. A heterogeneous distribution of ozone concentration has been found at the gas–liquid interface enlightening the competition between mass transfer and chemical reaction during the initial reaction time, which was most likely due to the unsteady phase holdup distributions and pollutant removal efficiencies.

The TolC-like Protein HgdD of the Cyanobacterium Anabaena sp. PCC 7120 Is Involved in Secondary Metabolite Export and Antibiotic Resistance

The role of TolC has largely been explored in proteobacteria, where it functions as a metabolite and protein exporter. In contrast, little research has been carried out on the function of cyanobacterial homologues, and as a consequence, not much is known about the mechanism of cyanobacterial antibiotic uptake and metabolite secretion in general. It has been suggested that the TolC-like homologue of the filamentous, heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, termed heterocyst glycolipid deposition protein D (HgdD), is involved in both protein and lipid secretion. To describe its function in secondary metabolite secretion, we established a system to measure the uptake of antibiotics based on the fluorescent molecule ethidium bromide. We analyzed the rate of porin-dependent metabolite uptake and confirmed the functional relation between detoxification and the action of HgdD. Moreover, we identified two major facilitator superfamily proteins that are involved in this process. It appears that anaOmp85 (Alr2269) is not required for insertion or assembly of HgdD, because an alr2269 mutant does not exhibit a phenotype similar to the hgdD mutant. Thus, we could assign components of the metabolite efflux system and describe parameters of detoxification by Anabaena sp. PCC 7120.