Papers by Cesar N Pegoraro
Biofouling, 2020
Abstract The use of hyperhalophilic microorganisms is emerging as a sustainable alternative to cl... more Abstract The use of hyperhalophilic microorganisms is emerging as a sustainable alternative to clean hydrocarbon-polluted hypersaline water bodies. In line with this practice, this work reports on the ability of the archaeon Halobacterium salinarum to develop biofilms on a solid surface conditioned by the presence of phenanthrene crystals, which results in the removal of the contaminating compound. The cell surface hydrophobicity does not change during the removal process and this organism is shown to constitutively produce a surfactant molecule with specific action on aromatic hydrocarbons, both indicating that phenanthrene removal might proceed through a non-contact mechanism. A new approach is presented to follow the process in situ through epifluorescence microscopy by monitoring phenanthrene auto-fluorescence. Graphical Abstract
Ecotoxicology and Environmental Safety, 2021
In the international framework India is finding a larger position for itself. This hope is focuse... more In the international framework India is finding a larger position for itself. This hope is focused on the belief that India is a prosperous democracy with substantial human and material resources; it is an increasingly strong economic power; it has a proven record as a responsible and law-abiding regime, and as a member of the non-aligned party it has consistently shared the interests of the developing nations. Indian foreign policy makers argue that India wants to re-invent itself at this point of 'take-off' as a great force. India needs new alliance for the proposed new position, including the dominant superpower, the United States of America (US). The US has said it would turn India into a great force. This essay attempts to examine the old pattern of relations with Russia that India had enjoyed. There's an Indo-US triangular alliance taking its place. How is this current type of strategic partnership distinct from that of the Indo Soviet/ Russian alliance? However, both countries' natural desire to strive towards multipolarity in world politics has helped restore the relationship, particularly over the past decade. Remarkably, ties with the US no longer stand in the way of stronger relations between India and Russia. The turbulent security climate marked by what is frequently assumed to be the state-sponsored insurgency in vulnerable Asian areas, the war in Afghanistan, and the political turmoil in both Afghanistan and Central Asian countries has paved the way for a strategic alliance between India and Russia.
Ecotoxicology and Environmental Safety, 2020
The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyl... more The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyls (PCBs) in soil, mimicking three strategies: (a) mycoaugmentation: by the addition of Trametes sanguinea and Pleurotus sajor-caju co-cultures immobilized on sugarcane bagasse; (b) biostimulation: by supplementation of sugarcane bagasse; and (c) natural attenuation: no amendments. The experiments were done in microcosms using Ultisol soil. Remediation effectiveness was assessed based on pollutants content, soil characteristics, and ecotoxicological tests. Biostimulation and mycoaugmentation demonstrated the highest PCBs-removal (approx. 90%) with a significant toxicity reduction at 90 d. The studied strains were able to survive during the incubation period in non-sterilized soil. Laccase, manganese-peroxidase and endoxylanase activities increased significantly in co-cultures after 60 d. Sugarcane bagasse demonstrated to be not only a suitable support for fungal immobilization but also an efficient substrate for fungal colonization of PCBs-contaminated soils. Mycoaugmentation and biostimulation with sugarcane bagasse improved oxidable organic matter and phosphorous contents as well as dehydrogenase activity in soil. Therefore, biostimulation with sugarcane bagasse and mycoaugmentation applying dual white-rot fungal cultures constitute two efficient bioremediation alternatives to restore PCBs-contaminated soils.
Atmospheric Pollution Research, 2020
Abstract Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and semivolatile pollutants assoc... more Abstract Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and semivolatile pollutants associated with emissions from both natural and anthropogenic sources. For decades, the atmosphere has been considered an efficient vehicle for pollutants transport around the world. In order to assess the atmospheric occurrence of PAHs across a transect in the Southwest Atlantic Ocean, air samples were collected aboard the oceanographic vessel ARA Puerto Deseado (CONICET), during two consecutive research campaigns in October–November 2014. Total PAHs were dominated by gas phase levels of Phenantrene, Dibenzothiophene, Fluorene, Fluoranthene and Pyrene in a concentration range of 57–5778 pg m−3. Characteristic diagnostic ratios of some PAHs were estimated in order to assess their possible emission sources showing important contribution from petrogenic and pyrogenic origin. Additionally, air mass back trajectory calculation revealed a marked influence of air with oceanic origin, being the contribution from the South American continent scarce. PAHs levels showed a decreasing trend from the coast towards open ocean, with exception of those sites that showed continental air masses influence.
International Journal of Environment and Health, 2018
Israel-Deaconess, who was a close colleague of Dr. Seidman for the last decade. Together they wor... more Israel-Deaconess, who was a close colleague of Dr. Seidman for the last decade. Together they worked side by side exploring many aspects of early detection of schizophrenia and educating trainees and the public on their findings. He will sum up the legacy of Dr. Seidman to the field and how we can continue it into the future.
Natural Product Research, 2019
The present study shows the variability in chemical profiles of three different varieties of Cann... more The present study shows the variability in chemical profiles of three different varieties of Cannabis sativa extracts used in medicinal cannabis oil when using two different extraction and evaporation methods. Procedures were compared by analyzing rate of total terpenoids to the principal cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD), using gas chromatography coupled to mass spectrometry (GC-MS). The extraction of inflorescences using soxhlet method showed the highest mass of final extract. Also, the use of heating and the presence of oxygen when evaporating the solvents, greatly modified the final profiles due to evaporation or chemical reactions. These variations in chemical profiles must be carefully taken into account and standardized in the elaboration of medicinal oils.
Ecotoxicology, 2017
Sediment-living organisms can be subjected to a multi-pollution condition due to an increase in t... more Sediment-living organisms can be subjected to a multi-pollution condition due to an increase in the diversity of contaminants. Sediment mixtures of Mercury (Hg) and some polycyclic aromatics hydrocarbons like Pyrene (Pyr) are common in heavily industrialized coastal zones. In the present study, greater than (>) and less than (<) probable effect concentration levels (PELs) of Hg and Pyr were assessed using spiked sediments in order to determine combined (Hg + Pyr) effects in uptake, metabolization and oxidative balance in the polychaete Perinereis gualpensis at short and medium-term exposure. Hg + Pyr significantly influenced the uptake/kinetics of Hg and Pyr metabolite 1-OH-pyrene in polychaete tissues during the exposure time compared with separate treatments of each analyte (p < 0.05). Both the Hg-only and Pyr-only exposures significantly influenced both enzymatic and non-enzymatic responses respect to control groups (p < 0.05). The Hg-only treatment showed the worst scenario related to the activation and subsequent inhibition of glutathione S- transferase (GST) and peroxidase (GPx) activities, high levels of Thiol-groups (SH-groups), low antioxidant capacity (ACAP) and enhanced lipid peroxidation (TBARS) in the last days of exposure (p < 0.05). In contrast, ragworms exposed to Hg + Pyr showed a significant increase in both enzymatic and non-enzymatic activity during the first days of exposure and the absence of lipid peroxidation during the whole experiment. Our results suggest different oxidative stress scenarios in P. gualpensis when exposed to >PEL Hg concentration with <PEL Pyr in sediments. Results also reveal the importance of the exposure time, endpoints involved as well as of the contaminant monitoring during the whole experiments in assessing the interactive effects of the contaminant mixture.
A retrospective analysis of a comprehensive series of high-volume air samples (n = 70) collected ... more A retrospective analysis of a comprehensive series of high-volume air samples (n = 70) collected during 2010-2011 in Toronto (Canada) was performed. Seven UV compounds were analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS) with sum of concentrations (gas + particle phase) ranging from 80 to 2030 pg/m 3 . Homosalate (HMS) was the most prevalent organic UV-filter in air (47% of the total concentration), followed by 2-ethylhexyl salicylate (EHS, ∼29%), E-and Z-2-ethylhexyl 4-methoxycinnamate (EHMC, ∼17%). Ambient air (gas + particle phase) concentrations of organic UVfilters showed a strong seasonality, with peak levels during the summer. An analysis of Clausius-Clapeyron slopes indicated that much of the ambient burden of organic UV-filters are explained by volatilization from terrestrial and aquatic surfaces and supplemented with human activities and use of lotions and sunscreens, containing organic UV-filters, in addition to its use in plastics, textiles, paints, and pesticides. The results showed that organic UVfilters exist mainly in the gas phase with some exceptions, for instance, octocrylene (OCR), which was associated with both gas and particle phases, and avobenzone (AVB), which was predominantly in the particle phase. Lastly, this study revealed the need for basic physical chemical property data for organic UV-filters, including information on transformation rates and products, for better evaluating their environmental fate and effects.
Environmental Science and Pollution Research
The occurrence of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs... more The occurrence of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of six sites with different emission sources in the province of Córdoba, Argentina, was analyzed. The sites included urban, industrial, agricultural, and mountain areas. Samples were collected using passive air samplers (PAS) consisting of polyurethane foam disks (PUF). Samples were analyzed for 12 PAHs, 31 polychlorinated biphenyls (PCBs), 12 organochlorine pesticides (OCPs), and 11 polybrominated diphenyl ethers (PBDEs). The concentrations of PAHs in the atmosphere were elevated at urban sites and were even higher at the industrial site. With respect to OCPs, it was observed that the concentrations of endosulfan were greater at the agricultural site (AGR) (416 ± 4 pg m −3). For hexachlorocyclohexanes (HCHs), only the alpha isomer was detected and there were minimal differences between the different sampling sites (5.9-13.3 pg m −3). In the case of dieldrin, the highest concentrations (33.6 pg m −3) were found at the mountain site, which may have been due to its use for insect control. Although heptachlor epoxide was not detected, the concentration of heptachlor was significantly higher at the agricultural and downtown sites (∼ 3.6 pg m −3). Regarding DDTs, the isomers p,p′-DDT and p,p′-DDE showed the highest concentrations at the mountain site (ΣDDT 120 ± 12 pg m −3) and downtown site (ΣDDT 157 ± 62 pg m −3). The relationship between the isomers suggested that at the downtown site, the contribution of this pesticide to the environment was recent, probably for the control of diseases vectors. The congener pattern of PBDEs was dominated by BDE-47, and BDE-99 at all sites, with the downtown site having the highest concentrations of compound esters (ΣPBDEs 118 ± 38 pg m −3). Finally, high concentrations of PCBs were found at the industrial site (ΣPCBs 1677 ± 134 pg m −3), and the predominating homologs were 5-Cl and 6-Cl, in contrast to the other sites where PCBs were dominated by 3-Cl and 4-Cl. This is the first study of POPs carried out in the province of Córdoba.
Chemosphere, 2015
2-Ethylhexyl 4-methoxycinnamate is one of the UVB blocking agents more widely used in a variety o... more 2-Ethylhexyl 4-methoxycinnamate is one of the UVB blocking agents more widely used in a variety of industrial fields. There are more than one hundred industrial suppliers worldwide. Given the enormous annual consumption of octinoxate, problems that arise due to the accumulation of this compound in nature should be taken into consideration. The GC-RT was used in this work with the aim of determining the vapor pressure, enthalpies of vaporization and octanol-air partition coefficient, for the BBP, DOP, E- and Z-EHMC esters. The results showed that Z-EHMC is almost five times more volatile than E-EHMC. Moreover, BBP, Z-EHMC and E-EHMC can be classified as substances with a relatively low mobility since they lie within the range of 8&amp;amp;amp;amp;amp;amp;amp;amp;lt;logKOA&amp;amp;amp;amp;amp;amp;amp;amp;lt;10 and -4&amp;amp;amp;amp;amp;amp;amp;amp;lt;log(PL/Pa)&amp;amp;amp;amp;amp;amp;amp;amp;lt;-2, while DOP lies in the range of logKOA&amp;amp;amp;amp;amp;amp;amp;amp;gt;10 and log(PL/Pa)&amp;amp;amp;amp;amp;amp;amp;amp;lt;-4, therefore, a low mobility can be expected. From these parameters, their particle-bound fraction and gas-particle partition coefficient were also derived.
Inorganic Chemistry, 2012
We describe in this paper the properties of [Ru(II/III)(bpy)(2)ClL](+1/+2) and [Ru(II/III)(bpy)(2... more We describe in this paper the properties of [Ru(II/III)(bpy)(2)ClL](+1/+2) and [Ru(II/III)(bpy)(2)L(2)](+2/+3). L = ditolyl-3-pyridylamine (dt3pya) is a redox active ligand related to triarylamines, which is very similar to 3-aminopyridine except for the reversible redox behavior. The monosubstituted complex shows a metal-to-ligand charge-transfer (MLCT) at 502 nm, and reversible waves in acetonitrile at E(0)(Ru(III/II)) = 1.07 V, E(0)(L(+/0)) = 1.46 V (NHE). The disubstituted complex shows an MLCT at 461 nm, a photorelease of dt3pya with quantum yield of 0.11 at 473 nm, and two reversible one-electron overlapped waves at 1.39 V associated with one of the ligands (1.37 V) and Ru(III/II) (1.41 V). Further oxidation of the second ligand at 1.80 V forms a 2,2&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-bipiridine derivative, in an irreversible reaction similar to dimerization of triphenylamine to yield tetraphenylbenzidine. In the dioxidized state, the spectroelectrochemistry of the disubstituted complex shows a ligand-to-ligand charge transfer at 1425 nm, with a transition moment of 1.25 Å and an effective two-state coupling of 1200 cm(-1). No charge transfer between ligands was observed when Ru was in a 2+ oxidation state. We propose that a superexchange process would be involved in ligand-metal-ligand charge transfer, when ligands and metals are engaged in complementary π interactions, as in metal-ligand-metal complexes. Best orbital matching occurs when metallic donor fragments are combined with acceptor ligands and vice versa. In our case, Ru(III) bridge (an acceptor) and two dt3pya (donors, one of them being oxidized) made the complex a Robin-Day Class II system, while the Ru(II) bridge (a donor, reduced) was not able to couple two dt3pya (also donors, one oxidized).
Science of The Total Environment, 2016
The occurrence of persistent organic pollutants (POPs) in the atmosphere of the near-coast South ... more The occurrence of persistent organic pollutants (POPs) in the atmosphere of the near-coast South Atlantic Ocean was studied. Air samples were collected using a high-volume air sampler (filter and polyurethane foam) on board the Argentinean research cruise R/V Puerto Deseado (CONICET). Samples were analyzed for 50 polychlorinated biphenyl (PCBs), 22 organochlorine pesticides (OCPs) and 14 polybrominated diphenyl ethers (PBDEs). These POPs classes showed a trend of decreasing levels from near-shore to open ocean sites. OCPs and PCBs were in the same order of magnitude (2.71-87.1pg/m(3) and 9.56-130pg/m(3), respectively) while PBDEs levels were significantly lower (0.69-2.58pg/m(3)). Dichlorodiphenyltrichloroethanes (DDTs), endosulfans, chlordanes, hexachlorocyclohexanes (HCHs) and heptachlors were between 0.20 and 17.8pg/m(3), while drines and hexachlorobenzene (HCB) were at lower levels (0.28-3.71pg/m(3)). The most frequently detected PCBs were congeners 32, 28, 44, 52, 95, representing &amp;amp;amp;amp;amp;amp;amp;amp;gt;50% of the total. The PBDEs congener pattern was dominated by congener 209 (70%), followed by 47 and 99 (16% and 7%, respectively). Air parcel back trajectories for the study period provided few insights as trajectories mainly stemmed from the open ocean with limited inputs from continental sources. These results indicate that the concentration of POPs (namely PCBs, OCPs, and PBDEs) in air remain elevated in the near-shore environment and then drop-off substantially beyond a distance of about 400km. This has implications for the loading of POPs and delivery to the marine environment in the near coastal zone.
Physical Chemistry …, 2011
Phys. Chem. Chem. Phys., 2011, Advance Article DOI:10.1039/C1CP22086A (Communication) PDF Version... more Phys. Chem. Chem. Phys., 2011, Advance Article DOI:10.1039/C1CP22086A (Communication) PDF Version. Charge transfer properties of Tröger base derivatives. Cristina. L. Ramíreza, César Pegoraroa, Leandro Truppb, Andrea ...
Ecotoxicology and Environmental Safety , 2021
Chlorothalonil (CLT) is a broad spectrum, and non-systemic fungicide applied in foliar structures... more Chlorothalonil (CLT) is a broad spectrum, and non-systemic fungicide applied in foliar structures to prevent and treat pathogens. This compound reaches to aquatic environments and affects the biota. In this context, the main goal of this study was to assess the effects of CLT at biochemical, tissular, and individual levels of biological organization using the invasive bivalve Corbicula largillierti as a bioindicator species. Clams were exposed to different sublethal concentrations (0, 10, 20 and 50 µg. L − 1 CLT) for 96 h. At biochemical level, the enzymatic activity (Glutathione-s-Transferase, Catalase, Acetyl-, Butiryl-and Carboxyl-esterases) and lipid peroxidation were measured in gills and the visceral mass. Also, the digestive gland morphometry through quantitative his-tological indexes was registered at the tissular level. Finally, filtering activity and burial behavior at the individual level were measured. At the highest CLT concentration, the most significant changes were observed in enzymatic activity (except for butyrylcholinesterase), lipid peroxidation and in digestive gland morphometry. It was also registered increases of the filtering activity and the latency time to burial. Most of the biomarkers assessed showed significant responses under CLT exposure. Therefore, taking into account that C. largillierti was affected by CLT, it can be expected that other species could be in a potential risk if this fungicide is present in freshwater systems.
Physical Chemistry Chemical Physics, 2011
Two triarylamine centers bridged through an aliphatic bridge feature unexpected charge transfer p... more Two triarylamine centers bridged through an aliphatic bridge feature unexpected charge transfer properties, bearing an important electronic coupling between them in the absence of a π linker; EPR, electrochemistry, electronic spectroscopy and first principles molecular calculations are combined to study the electronic structure of this compound.
Inorganic chemistry, 2012
We describe in this paper the properties of [Ru II/III (bpy) 2 ClL] +1/+2 and [Ru II/III (bpy) 2 ... more We describe in this paper the properties of [Ru II/III (bpy) 2 ClL] +1/+2 and [Ru II/III (bpy) 2 L 2 ] +2/+3. L = ditolyl-3-pyridylamine (dt3pya) is a redox active ligand related to triarylamines, which is very similar to 3-aminopyridine except for the reversible redox behavior. The monosubstituted complex shows a metal-to-ligand charge-transfer (MLCT) at 502 nm, and reversible waves in acetonitrile at E 0 (Ru III/II) = 1.07 V, E 0 (L +/0) = 1.46 V (NHE). The disubstituted complex shows an MLCT at 461 nm, a photorelease of dt3pya with quantum yield of 0.11 at 473 nm, and two reversible one-electron overlapped waves at 1.39 V associated with one of the ligands (1.37 V) and Ru III/II (1.41 V). Further oxidation of the second ligand at 1.80 V forms a 2,2′-bipiridine derivative, in an irreversible reaction similar to dimerization of triphenylamine to yield tetraphenylbenzidine. In the dioxidized state, the spectroelectrochemistry of the disubstituted complex shows a ligand-to-ligand charge transfer at 1425 nm, with a transition moment of 1.25 Å and an effective two-state coupling of 1200 cm −1. No charge transfer between ligands was observed when Ru was in a 2+ oxidation state. We propose that a superexchange process would be involved in ligand−metal−ligand charge transfer, when ligands and metals are engaged in complementary π interactions, as in metal−ligand−metal complexes. Best orbital matching occurs when metallic donor fragments are combined with acceptor ligands and vice versa. In our case, Ru III bridge (an acceptor) and two dt3pya (donors, one of them being oxidized) made the complex a Robin−Day Class II system, while the Ru II bridge (a donor, reduced) was not able to couple two dt3pya (also donors, one oxidized). ■ INTRODUCTION Mixed-valence compounds have played a central role in the understanding of how electron transfer occurs in a variety of systems whose properties (color, electrical conductivity, magnetism) derive from this phenomenon. This topic has been systematized in a series of reviews, 1−10 and its influence on the field of electron transfer has been so strong that we are currently able to trace applications of the intervalence concept in fields so apparently unconnected as magnetoresistance, 11 energy conversion, 12 and molecular electronics. 13 The most important strength of intervalence compounds, such as the Creutz-Taube cation, is that they allow us to spectroscopically interrogate the system that actually performs the electron transfer event. This observation is not possible while studying homogeneous redox reactions like solution self-exchange Fe(H 2 O) 6 2+ /Fe(H 2 O) 6 3+ (a classic example), because reacting ions are nonassociated most of the time and spectroscopies are usually not sensitive enough to allow studying the small concentration of associated reactants. Although ligands are usually organic molecules, and organic mixed valence systems have made important contributions to this field, 14 ligand-focused charge transfer and ligand−metal− ligand mixed valence compounds are notoriously scarce in electron transfer literature. 15 The set of compounds studied so far is small because most redox-active ligands are also involved in coupled irreversible chemical reactions that hinder molecular interrogation (usually formation of multiple N−C bonds accompanied by proton transfer after the electrochemical step 16). The analysis of these systems focused on ligand charge transfer should not differ essentially from the classical metal− ligand−metal system like the Creutz-Taube cation, because the underlying electron transfer theory is independent of the nature of the fragments involved in redox reactions. It has been proposed 15 that a pure ligand−ligand charge transfer (a concept analogous to a metal−metal intervalence charge transfer) must have no influence of the central metal. In this extreme situation, the metal locates the ligands in such a way that direct orbital overlapping results in electronic coupling. In other words, the metal has a structural connectivity role but not an electronic (orbital) role. On the basis of the experience of the historically metal-focused mixed valence chemistry, this extreme situation of negligible coupling between adjacent metal−ligand pairs and non-negligible coupling
Environmental Science & Technology, 2020
A retrospective analysis of a comprehensive series of high volume air samples (n=70) collected du... more A retrospective analysis of a comprehensive series of high volume air samples (n=70) collected during 2010-2011 in Toronto (Canada) was performed. Seven UV compounds were analyzed by GC-MS/MS with sum of concentrations (gas + particle phase) ranging from 80-2030 pg/m3. Homosalate (HMS) was the most prevalent organic UV-filter in air (47% of the total concentration), followed by 2-ethylhexyl salicylate (EHS, ∼29%), E- and Z-2-ethylhexyl 4-methoxycinnamate (EHMC, ∼17%). Ambient air (gas+particle phase) concentrations of organic UV-filters showed a strong seasonality, with peak levels during the summer. An analysis of Clausius-Clapeyron slopes indicated that much of the ambient burden of organic UV-filters is explained by volatilization from terrestrial and aquatic surfaces and supplemented with human activities and use of lotions and sunscreens, containing organic UV-filters, in addition to the its use in plastics, textiles, paints and pesticides. The results showed that organic UV-filters exist mainly in the gas phase with some exceptions. For instance, octocrylene (OCR), which was associated with both gas and particle phases, and avobenzone (AVB), which was predominantly in the particle phase. Lastly, this study revealed the need for basic physical chemical property data for organic UV-filters, including information on transformation rates and products, for better evaluating their environmental fate and effects.
Ecotoxicology and Environmental Safety , 2020
The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyl... more The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyls (PCBs) in soil, mimicking three strategies: (a) mycoaugmentation: by the addition of Trametes sanguinea and Pleurotus sajor-caju co-cultures immobilized on sugarcane bagasse; (b) biostimulation: by supplementation of sugarcane bagasse; and (c) natural attenuation: no amendments. The experiments were done in microcosms using Ultisol soil. Reme-diation effectiveness was assessed based on pollutants content, soil characteristics, and ecotoxicological tests. Biostimulation and mycoaugmentation demonstrated the highest PCBs-removal (approx. 90%) with a significant toxicity reduction at 90 d. The studied strains were able to survive during the incubation period in non-sterilized soil. Laccase, manganese-peroxidase and endoxylanase activities increased significantly in co-cultures after 60 d. Sugarcane bagasse demonstrated to be not only a suitable support for fungal immobilization but also an efficient substrate for fungal colonization of PCBs-contaminated soils. Mycoaugmentation and biostimulation with sug-arcane bagasse improved oxidable organic matter and phosphorous contents as well as dehydrogenase activity in soil. Therefore, biostimulation with sugarcane bagasse and mycoaugmentation applying dual white-rot fungal cultures constitute two efficient bioremediation alternatives to restore PCBs-contaminated soils.
Biofouling, 2020
The use of hyperhalophilic microorganisms is emerging as a sustainable alternative to clean hydro... more The use of hyperhalophilic microorganisms is emerging as a sustainable alternative to clean hydrocarbon-polluted hypersaline water bodies. In line with this practice, this work reports on the ability of the archaeon Halobacterium salinarum to develop biofilms on a solid surface conditioned by the presence of phenanthrene crystals, which results in the removal of the contaminating compound. The cell surface hydrophobicity does not change during the removal process and this organism is shown to constitutively produce a surfactant molecule with specific action on aromatic hydrocarbons, both indicating that phenanthrene removal might proceed through a non-contact mechanism. A new approach is presented to follow the process in situ through epifluorescence microscopy by monitoring phenanthrene auto-fluorescence.
Natural Product Research, 2019
The present study shows the variability in chemical profiles of three different varieties of Cann... more The present study shows the variability in chemical profiles of three different varieties of Cannabis sativa extracts used in medicinal cannabis oil when using two different extraction and evaporation methods. Procedures were compared by analyzing rate of total terpenoids to the principal cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD), using gas chromatography coupled to mass spectrometry (GC-MS). The extraction of inflorescences using soxhlet method showed the highest mass of final extract. Also, the use of heating and the presence of oxygen when evaporating the solvents, greatly modified the final profiles due to evaporation or chemical reactions. These variations in chemical profiles must be carefully taken into account and standardized in the elaboration of medicinal oils.
Uploads
Papers by Cesar N Pegoraro