Publications

Abstract Biosurfactants and bioemulsifiers (BS/BE) are naturally synthesized molecules, which can be used as alternatives to traditional detergents. These molecules are commonly produced by microorganisms isolated from hydrocarbon-rich environments. Gordonia alkanivorans strain 1B was originally found in such an environment, however little was known about its abilities as a BS/BE producer. The goal of this work was to access the potential of strain 1B as a BS/BE producer and perform the initial characterization of the produced compounds. It was demonstrated that strain 1B was able to synthesize lipoglycoprotein compounds with BS/BE properties, both extracellularly and adhered to the cells, without the need for a hydrophobic inducer, producing emulsion in several different hydrophobic phases. Using a crude BS/BE powder, the critical micelle concentration was determined (CMC = 16.94 mg/L), and its capacity to reduce the surface tension to a minimum of 35.63 mN/m was demonstrated, surpassing many commercial surfactants. Moreover, after dialysis, emulsification assays revealed an activity similar to that of Triton X-100 in almond and sunflower oils. In benzene, the E-24 value attained was 83.45%, which is 30% greater than that of the commercial alternative. The results obtained highlight for the presence of promising novel BS/BE produced by strain 1B.

Abstract The present study aimed to validate a control method on the gas chromatography system (GC) based on the experimental design strategy, to examine the changes and correlation between the fermentation process and the quality of alcoholic and non-alcoholic beer product, especially the formation of diacetyl. On the other hand, spectrophotometric methods were applied to the determination of polyphenols content and the potential antioxidant activity of beer during different fermentation processes. with this aim, three modes of barley fermentation were used, specifically classical fermentation, stopped fermentation and thermal process. The results showed that the different fermentation modes had a major impact on diacetyl production. The highest concentration was obtained using stopped fermentation 0.36 mg/L, the lowest concentration value 0.07 mg/L was detected using the thermal process. Monitoring the increase of oxygen concentration between fermentation, filtration, and filling of the final product (32, 107, 130 ppm, respectively) has a significant impact on the concentration of diacetyl. The obtained results of spectrophotometric analysis showed that the total antioxidant activity changed during beer fermentation process and demonstrate that the extend of the antioxidant activity was very much dependent on the total polyphenolic content with a higher value in Hopped wort (13.41%, 65 mg GAE 100 mL(-1), 28 mg CE 100 mL(-1)) for antioxidant potential, total phenolic content, and total flavonoids content, respectively, whereas the lowest values was detected in Non-alcoholic beer using thermal process (7.24%, 35 mg GAE 100 mL(-1), 10 mg CE 100 mL(-1)) for antioxidant potential, total phenolic contents, and total flavonoids contents, respectively. Based on the results achieved, we reveal the impact of the fermentation process on the nutritional value of the final product.

Abstract The chemical characterization of the Ghis-Nekor groundwater has become a concern of many researchers in Morocco. It is a crucial indicator for the environment situation and the socioeconomic development of this Moroccan region. Indeed, it helps decisionmakers carry out conscious and sustainable management. For this reason, 20 samples of the Ghis-Nekor aquifer were examined in terms of physicochemical parameters such as pH, temperature, electrical conductivity (EC), and total alkalinity (Alk), major cations-anions (Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42-, NO3-, and TDS), isotopic elements (delta O-18, delta H-2, and delta C-13), and concentrations of Br and Sr anions in 2020. Furthermore, spatial data analysis with a geographic information system (GIS) using the ArcGis software (Redlands, California, USA). Indeed, static maps show significant water quality information that helps characterize the groundwater of the study area. The spatial analysis by the GIS indicates that except the EC (from 2630 to 6950 mS/cm), all the physical parameters showed standard concentration values in most of the samples. A significant concentration above the Moroccan norm of groundwater quality for sodium (Na+) from 264.3 to 1500 mg/L, chlorides (Cl-) concentrations from 408.3 to 1510 mg/L, SO42- from 313.1 to 999.2 mg/L, and bicarbonate (HCO3-) from 283.7 to 679.8 mg/L was observed, while all the points exceeded the recommended standards norm for SO42-. Most of the points met the potability standards for potassium (K+). In terms of the isotopic elements, the concentration values of delta O-18 were from -3.92 & PTSTHOUSND; to -5.60 & PTSTHOUSND;, while the delta H-2 concentration values varied between -28.67 & PTSTHOUSND; and -39.99 & PTSTHOUSND;. The analysis revealed values of carbon isotope delta C-13 ranging between -3.15 & PTSTHOUSND; and -8.61 & PTSTHOUSND;, thus suggesting that the origin of the carbon is mineral, mainly deriving from calcite dissolution. The analysis of the bromide and strontium contents made it possible to discriminate the origin of the salinity anomalies. The Cl/Br, Br/Cl, and Sr/Ca molar ratios distinguished the areas of influence of geological setting (saliferous facies outcrops) or anthropogenic effect (wastewater). The results of the analysis shed light on factors of contamination, which are as follows: urban zones (Imzourene, Ait Youssef, and Souani) and agricultural activities. Therefore, the use of these waters could pose a risk to the health of humans and animals. Similarly, the GIS is a practical and effective tool for the Ghis-Nekor groundwater quality diagnostics and could help decisionmakers establish solutions.

Abstract Mitochondria are key organelles involved in cellular survival, differentiation, and death induction. In this regard, mitochondrial morphology and/or function alterations are involved in stress-induced adaptive pathways, priming mitochondria for mitophagy or apoptosis induction. We have previously shown that the mitochondriotropic antioxidant AntiOxCIN(4) (100 mu M; 48 h) presented significant cytoprotective effect without affecting the viability of human hepatoma-derived (HepG2) cells. Moreover, AntiOxCIN(4) (12.5 mu M; 72 h) caused a mild increase of reactive oxygen species (ROS) levels without toxicity to primary human skin fibroblasts (PHSF). As Nrf2 is a master regulator of the oxidative stress response inducing antioxidant-encoding gene expression, we hypothesized that AntiOxCIN(4) could increase the resistance of human hepatoma-derived HepG2 to oxidative stress by Nrf2-dependent mechanisms, in a process mediated by mitochondrial ROS (mtROS). Here we showed that after an initial decrease in oxygen consumption paralleled by a moderate increase in superoxide anion levels, AntiOxCIN(4) led to a time-dependent Nrf2 translocation to the nucleus. This was followed later by a 1.5-fold increase in basal respiration and a 1.2-fold increase in extracellular acidification. AntiOxCIN(4) treatment enhanced mitochondrial quality by triggering the clearance of defective organelles by autophagy and/or mitophagy, coupled with increased mitochondrial biogenesis. AntiOxCIN(4) also up-regulated the cellular antioxidant defense system. AntiOxCIN(4) seems to have the ability to maintain hepatocyte redox homeostasis, regulating the electrophilic/nucleophilic tone, and preserve cellular physiological functions. The obtained data open a new avenue to explore the effects of AntiOxCIN(4) in the context of preserving hepatic mitochondrial function in disorders, such as NASH/NAFLD and type II diabetes.

Abstract Activated carbon modified by phosphoric acid noted CAa was successfully used as a new low-cost adsorbent for removing Cu2+, Ni2+ and Cr6+ metal ions from artificially contaminated aqueous solutions. Experiments were performed in batches for adsorption kinetics and isotherms. Scanning electron microscope (SEM) observations as well as a nitrogen adsorption-desorption BET surface area measurement showed the formation of mesoporous CAa with an average pore size of 3.1 nm and a surface area of ABET = 678.74 m(2) g(-1). The adsorption data for Cu2+, Ni2+ and Cr6+ fitted well with Langmuir adsorption model with maximum adsorbed amount of 238.10 mg g(-1) for Cu(II), 80.64 mg g(-1) for Ni(II) and 125 mg g(-1) of Cr(VI) with the maximal amount measured by N-2 adsorption of 231.5337 cm(3) g(-1) STP. The experimental variables studied were pH, temperature, amount of biomass and initial ion concentration. Maximum biosorption was observed for pH = 2. The adsorption capacity seems to be optimized by increasing the temperature, the amount of biosorbent and the initial concentration. Isotherm adsorptions are in agreement with Langmuir models. The calculated changes in adsorption free energy (Delta G degrees), enthalpy (Delta H degrees) and entropy (Delta S degrees) confirm that the present adsorption process is a favorable, endothermic and spontaneous phenomenon.

Abstract American trypanosomiasis or Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and is considered a neglected disease, being an important problem for public health. Benznidazole (BZN) is the drug used to treat the disease. However, it has limited efficacy and adverse side effects. Therefore, the development of new therapeutic alternatives is necessary. In this work, the trypanocidal activity and cytotoxicity of a series of catechol-containing 3-arylcoumarins, their combination with BZN, and the inclusion in beta-cyclodextrins (beta-CDs), were evaluated. The results obtained showed that the entire series has moderate trypanocidal activity on the trypomastigote form of the parasite, being the 3-(4'-bromophenyl)-6,7-dihydroxycoumarin (8) the most active compound (IC50 = 34 mu M) and the most cytotoxic in Vero cells (IC50= 162 mu M) as well. By forming the inclusion complex 8-beta-CDs, the trypanocidal activity and cytotoxicitydecreased. In addition, the formation of inclusion complexes increased the solubility. The possible mechanism of action of 8 was evaluated and proved to be through the generation of oxidative stress. The combination with BZN presented a synergistic effect on the trypanocidal activity, reducing the necessary dose of BZN. The presence of a catechol in the studied scaffold seems to modulate the trypanocidal activity, and the combination of drugs proved to be a promising alternative strategy for treating the disease. (C) 2021 The Authors. Published by Elsevier B.V. on behalf of King Saud University.

Abstract Superoxide anion is a reactive oxygen species (ROS) of biological interest. More specifically, it plays a role in intra- and intercellular signaling, besides being associated with conditions such as inflammation and cancer. Given this, efforts have been made by the research community to devise new sensing strategies for this ROS species. Among them, the chemiluminescent reaction of marine Coelenterazine has been employed as a sensitive and dynamic probing approach. Nevertheless, chemiluminescent reactions are typically associated with lower emissions in aqueous solutions. Herein, here we report the synthesis of a new Coelenterazine derivative with the potential for superoxide anion sensing. Namely, this novel compound is capable of chemiluminescence in a dose-dependent manner when triggered by this ROS species. More importantly, the light-emission intensities provided by this derivative were relevantly enhanced (intensities 2.13 x 10(1) to 1.11 x 10(4) times higher) in aqueous solutions at different pH conditions when compared to native Coelenterazine. The half-life of the chemiluminescent signal is also greatly increased for the derivative. Thus, a new chemiluminescence molecule with significant potential for superoxide anion sensing was discovered and reported for the first time.

Abstract Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated (OPAHs) and nitrated (NPAHs) derivatives are main chromophores of the carbonaceous aerosol brown carbon (BrC), which is linked with radiative forcing. Here, we investigated the atmospheric absorption spectra of 64 PAHs, OPAHs, and NPAHs directly over the Chinese megacity of Xi'an, by employing a time-dependent density functional theory (TD-DFT) computational approach and correcting the results for the experimentally determined atmospheric concentration of the studied molecules. The obtained data showed that these molecules contribute more to radiative forcing by absorbing light in the UVA and (sub)visible region of the spectrum. Investigating daily absorption spectra revealed major seasonal variation in the intensity of light absorption, but little changes in the shape of the absorption spectra. The observed light absorption can be explained mainly by contributions from PAHs and to a lesser extent by carbonyl-OPAHs, with relatively low contributions of the other OPAHs and NPAHs. Among them, benzo[b+j+k] fluoranthenes, benzo[e]pyrene, benzo[a]pyrene, benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, 6H-benzo[cd] pyren-6-one, 7H-benz[de]anthracen-7-one, and benz[a]anthracene-7,12-dione are highlighted as potentially problematic contributors for radiative forcing over Xi'an.

Abstract A catalytic ozonation advanced oxidation process (AOP) with a copper(II)-doped carbon dot as catalyst, Cu-CD (using L-cysteine and polyethylene glycol (PEG) as precursors and passivation agents), was developed for textile wastewater treatment (T = 25 degrees C and pH = 7). Four dyes were analyzed-Methyl Orange (MO), Orange II sodium salt (O-II), Reactive Black 5 (RB-5) and Remazol Brilliant Blue R (RBB-R), as well as a real effluent from the dying and printing industry. The Cu-CD, with marked catalytic ozonation properties, was successfully synthesized by one-pot hydrothermal procedure with a size of 4.0 nm, a charge of -3.7 mV and a fluorescent quantum yield of 31%. The discoloration of the aqueous dye solutions followed an apparent first-order kinetics with the following rate constants (k(ap) in min(-1)): MO, 0.210; O-II, 0.133; RB-5, 0.177; RBB-R, 0.086. In the presence of Cu-CD, the following apparent first-order rate constants were obtained (k(ap)(C) in min(-1)) with the corresponding increase in the rate constant without catalyst (%Inc): MO, 1.184 (464%); O-II, 1.002 (653%); RB-5, 0.709 (301%); RBB-R, 0.230 (167%). The presence of sodium chloride (at a concentration of 50 g/L) resulted in a marked increase of the discoloration rate of the dye solution due to generation of other radicals, such as chlorine and chlorine oxide, resulting from the reaction of ozone and chloride. Taking into consideration that the real textile effluent under research has a high carbonate concentration (>356 mg/L), which inhibits ozone decomposition, the discoloration first-order rate constants without and with Cu-CD (k(ap) = 0.0097 min(-1) and k(ap)(C) = 0.012 min(-1) (%Inc = 24%), respectively) were relatively small. Apparently, the Cu-CD, the surface of which is covered by a soft and highly hydrated caramelized PEG coating, accelerates the ozone decomposition and dye adsorption, increasing its degradation.