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Search Results: 1 - 10 of 374646 matches for " Juan F. Cárdenas-González "
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Hexavalent Chromium Removal by a Paecilomyces sp. Fungal Strain Isolated from Environment
Juan F. Cárdenas-González,Ismael Acosta-Rodríguez
Bioinorganic Chemistry and Applications , 2010, DOI: 10.1155/2010/676243
Abstract: A resistant and capable fungal strain in removing hexavalent chromium was isolated from an environment near of Chemical Science Faculty, located in the city of San Luis Potosí, Mexico. The strain was identified as Paecilomyces sp., by macro- and microscopic characteristics. Strain resistance of the strain to high Cr (VI) concentrations and its ability to reduce chromium were studied. When it was incubated in minimal medium with glucose, another inexpensive commercial carbon source like unrefined and brown sugar or glycerol, in the presence of 50?mg/L of Cr (VI), the strain caused complete disappearance of Cr (VI), with the concomitant production of Cr (III) in the growth medium after 7 days of incubation, at 28 , pH 4.0, 100?rpm, and an inoculum of 38?mg of dry weight. Decrease of Cr (VI) levels from industrial wastes was also induced by Paecilomyces biomass. These results indicate that reducing capacity of chromate resistant filamentous fungus Cr (VI) could be useful for the removal of Cr (VI) pollution. 1. Introduction Chromium (Cr) toxicity is one of the major causes of environmental pollution emanating from tannery effluents. This metal is used in the tanning of hides and leather, the manufacture of stainless steel, electroplating, textile dyeing, and as a biocide in the cooling waters of nuclear power plants, resulting chromium discharges causing environmental concerns [1]. Cr exists in nine valence states ranging from 2 to +6. Of these states, only hexavalent [Cr (VI)] and trivalent chromium [Cr (III)] have primary environmental significance because they are the most stable oxidation forms in the environment [2]. Both are found in various bodies of water and wastewaters [3]. Cr (VI) typically exists in one of these two forms: chromate ( ) or dichromate ( ), depending on the pH of the solution [3]. These two divalent oxyanions are very water soluble and poorly adsorbed by soil and organic matter, making them mobile in soil and groundwater [2]. Both chromate anions represent acute and chronic risks to animals and human health, since they are extremely toxic, mutagenic, carcinogenic, and teratogenic [4]. In contrast to Cr (VI) forms, the Cr (III) species: predominantly hydroxides, oxides, or sulphates, are less water soluble, mobile (100 times less toxic) [5], and (1000 times less) mutagenic [6]. The principal techniques for recovering or removing Cr (VI), from wastewater are chemical reduction and precipitation, adsorption on activated carbon, ion Exchange, and reverse osmosis, in a basic medium [7]. These methods present high cost, low efficieny
Remoción de Cromo Hexavalente por el Hongo Paecilomyces sp. Aislado del Medio Ambiente
Cárdenas-González,Juan F; Acosta-Rodríguez,Ismael;
Información tecnológica , 2011, DOI: 10.4067/S0718-07642011000100003
Abstract: a fungal strain resistant to cr (vi) and capable of removing the oxyanion from the médium was isolated from the environment near the chemical science faculty, university san luis potosí in méxico. the strain was identified as paecilomyces sp, by macro and microscopic characteristics. it was concluded that this fungal biomass can be used for the removal of cr (vi) in aqueous solutions, since 1 g of fungal biomass removes 100 y 1000 mg/100 ml of this metal after one and three hours of incubation, and removes 297 mg cr (vi) from contaminated soil.
Remoción de Cromo Hexavalente por el Hongo Paecilomyces sp. Aislado del Medio Ambiente Hexavalent Chromium Removal by a Paecilomyces sp Fungal Strain Isolated from Environment
Juan F Cárdenas-González,Ismael Acosta-Rodríguez
Información Tecnológica , 2011,
Abstract: Se aisló un hongo resistente y capaz de remover cromo hexavalente a partir del medio ambiente de una zona cercana a la Facultad de Ciencias Químicas, Universidad de San Luis Potosí en México. La cepa fue identificada como Paecilomyces sp, en base a sus características macro y microscópicas. La biomasa fúngica remueve eficientemente Cromo (VI) en solución y puede utilizarse para descontaminar nichos acuáticos contaminados, ya que 1 g de biomasa fúngica remueve 100 y 1000 mg/100 mL del metal a una y tres horas de incubación, y elimina totalmente 297 mg Cr(VI)/g de tierra contaminada. A fungal strain resistant to Cr (VI) and capable of removing the oxyanion from the médium was isolated from the environment near the Chemical Science Faculty, University San Luis Potosí in México. The strain was identified as Paecilomyces sp, by macro and microscopic characteristics. It was concluded that this fungal biomass can be used for the removal of Cr (VI) in aqueous solutions, since 1 g of fungal biomass removes 100 y 1000 mg/100 mL of this metal after one and three hours of incubation, and removes 297 mg Cr (VI) from contaminated soil.
Hexavalent Chromium Removal by Citrus limonium Shell  [PDF]
Juan Manuel Vargas-Morales, Diana Bautista-Mata, Juan F. Cárdenas-González, Ismael Acosta-Rodríguez, Víctor Manuel Martínez-Juárez
Open Journal of Inorganic Non-metallic Materials (OJINM) , 2012, DOI: 10.4236/ojinm.2012.23003
Abstract: We studied the Chromium(VI) removal capacity in aqueous solution by the lemon shell, using the diphenylcarbazide method to evaluate the metal concentration. So, the highest biosorption of the metal (50 mg/L) occurs within 100 minutes, at pH of 1.0, and 28°C. According to temperature, the highest removal was observed at 60°C, in 11 minutes, when the metal (1 g/L) is completely adsorbed. At the analyzed concentrations of Cr(VI), lemon shell, showed excellent removal capacity, besides it removes efficiently the metal in situ (97.2% removal, 7 days of incubation, 5 g of biomass). After 1 hour of incubation the studied biomass reduces 1.0 g of Cr(VI) with the simultaneous production of Cr(III); so it can be used to eliminate it from industrial wastewater.
Induction of Extracellular Lytic Enzymes by Fusarium solani  [PDF]
María de Guadalupe Moctezuma-Zárate, Juan Manuel Vargas-Morales, Juan F. Cárdenas-González, Víctor Manuel Martínez-Juárez, Ismael Acosta-Rodríguez
Advances in Microbiology (AiM) , 2013, DOI: 10.4236/aim.2013.38A005
Abstract:

Fusarium solani is a necrotrophic parasitic fungus that causes wilt in some plants, causing severe economic losses in some areas of the country. The objective of this work was to analyze the induction of extracellular lytic enzymes produced by a strain of F. solani, isolated from a culture of tomato, in Villa de Arista, S.L.P. México. Polygalacturonase activity has a greater induction time at 10 days, and the xylanase has two times higher activity at 8 and 13 days of incubation at 28?C. Also, the xylanase activities A and B were very stable at 4?C. After 7 days of incubation, it has an activity of 100% and 96%, respectively, while polygalacturonase retains 61% of its initial activity. Both activities are better induced with glutamate and urea as nitrogen sources respectively, and both exhibit an initial pH optimum of 5.5. Finally, we didnt find cellulase activity in the analyzing conditions.

Remoción de Cromo (VI) por una Cepa de Paecilomyces sp Resistente a Cromato
Cárdenas-González,Juan F; Martínez-Juárez,Víctor M; Acosta-Rodríguez,Ismael;
Información tecnológica , 2011, DOI: 10.4067/S0718-07642011000400006
Abstract: the ability to reduce chromium (vi) by a fungal strain of paecilomyces sp was studied. when it was incubated in minimal medium with glucose and other inexpensive commercial carbon sources such as unrefined and brown sugar or glycerol, in the presence of 50 mg/l of cr(vi), the strain caused complete removal of cr(vi). the reduction to cr (iii) occurs in the growth medium after 7 days of incubation, at 28°c, ph 4.0, and inoculum of 38 mg. also, the fungi efficiently reduced the concentration of cr(vi) from contaminated soil wastes. the results indicate that the fungal strain of paecilomyces sp has the capacity of reducing cr(vi) to cr(iii), and therefore it could be useful for the removal of cr(vi) pollution.
Remoción de Cromo (VI) por una Cepa de Paecilomyces sp Resistente a Cromato Removal of Chromium (VI) in a Chromate-Resistant Strain of Paecilomyces sp
Juan F Cárdenas-González,Víctor M Martínez-Juárez,Ismael Acosta-Rodríguez
Información Tecnológica , 2011,
Abstract: Se analizó la capacidad de remoción de Cr(VI) de una cepa de Paecilomyces sp. Cuando el hongo se incubó en medio mínimo con glucosa y otras fuentes de carbono comerciales y de bajo costo, como azúcar moscabada y piloncillo ó glicerol, en presencia de 50 mg/L de Cr(VI), removió totalmente el Cr(VI). La reducción a Cr(III) ocurre en el medio de cultivo después de 7 días de incubación a 28°C, pH 4.0, y un inoculo de 38 mg. El hongo también redujo eficientemente la concentración de Cr(VI) a partir de tierra contaminada. Los resultados indican que la cepa de Paecilomyces sp tiene la capacidad de reducir Cr(VI) a Cr(III), y por lo tanto puede utilizarse para eliminar la contaminación por Cr(VI). The ability to reduce chromium (VI) by a fungal strain of Paecilomyces sp was studied. When it was incubated in minimal medium with glucose and other inexpensive commercial carbon sources such as unrefined and brown sugar or glycerol, in the presence of 50 mg/L of Cr(VI), the strain caused complete removal of Cr(VI). The reduction to Cr (III) occurs in the growth medium after 7 days of incubation, at 28°C, pH 4.0, and inoculum of 38 mg. Also, the fungi efficiently reduced the concentration of Cr(VI) from contaminated soil wastes. The results indicate that the fungal strain of Paecilomyces sp has the capacity of reducing Cr(VI) to Cr(III), and therefore it could be useful for the removal of Cr(VI) pollution.
Biosorption of Mercury (II) from Aqueous Solutions onto Fungal Biomass
Víctor M. Martínez-Juárez,Juan F. Cárdenas-González,María Eugenia Torre-Bouscoulet,Ismael Acosta-Rodríguez
Bioinorganic Chemistry and Applications , 2012, DOI: 10.1155/2012/156190
Abstract: The biosorption of mercury (II) on 14 fungal biomasses, Aspergillus flavus I–V, Aspergillus fumigatus I-II, Helminthosporium sp., Cladosporium sp., Mucor rouxii mutant, M. rouxii IM-80, Mucor sp 1 and 2, and Candida albicans, was studied in this work. It was found that the biomasses of the fungus M. rouxii IM-80, M. rouxii mutant, Mucor sp1, and Mucor sp 2 were very efficient removing the metal in solution, using dithizone, reaching the next percentage of removals: 95.3%, 88.7%, 80.4%, and 78.3%, respectively. The highest adsorption was obtained at pH 5.5, at 30°C after 24 hours of incubation, with 1?g/100?mL of fungal biomass. 1. Introduction Heavy metal ion pollution has become wide spread throughout the world as a result of industrialization, which significantly threats the ecosystem, especially the people’s health due to their severe toxicity. In order to minimize the impacts of metals contaminated, wastewaters need to be treated before discharge to water bodies. Environmental mercury levels have increased considerably in recent years. The direct anthropogenic sources of mercury in water bodies are related to numerous industrial applications (e.g., chloroalkali productions, pharmaceutical and cosmetic preparations, electrical instruments, and pulp and paper industries) and many products of common use (e.g., thermometers, batteries, and medical drugs) [1]. Mercury is one of the priority pollutants listed by the USEPA as it can easily pass the blood-brain barrier and affect the fetal brain [2]. High concentrations of Hg (II) cause impairment of pulmonary function and kidney, chest pain, and dyspnea [3–6]. The illness, which came to be known as Minamata disease, was caused by mercury poisoning gas as a result of eating contaminated fish. Mercury has very high tendency for binding to proteins and it mainly affects the renal and nervous systems [7]. Mercury removal from wastewaters needs to achieve very low levels for all these reasons. Metal sorption by different types of biomaterials such as inactive dried biomass of algae, bacteria, and fungi can serve for removing metals from solution because of their unique chemical composition [8–10] investigated the metal binding capacity of the thermophilic bacteria Geobacillus thermodenitrificans. According to this study, bacterial biomass reduced the concentration of Fe3+ (91.31%), Cr3+ (80.80%), Co2+ (79.71%), Cu2+ (57.14%), Zn2+ (55.14%), Cd2+ (49.02%), Ag+ (43.25%), and Pb2+ (36.86%) at different optimum pH at 720?min [11], also it was investigated the biosorption of cadmium (II) from aqueous solutions by
Aislamiento e Identificación de Bacterias y Levaduras Resistentes a Petróleo
Acosta-Rodríguez,Ismael; Moctezuma-Zárate,María G; Tovar-Oviedo,Juana; Cárdenas-González,Juan F;
Información tecnológica , 2011, DOI: 10.4067/S0718-07642011000600011
Abstract: different microorganisms were isolated from various rivers of the huasteca potosina, in mexico that grow in the presence of petroleum as the sole carbon source. the activity of alcohol oxidase was determined by a colorimetric method. the most common bacteria present in the samples were pseudomonas aeruginosa (50%) and only one type of yeast was found, candida albicans (6.25%). furthermore, they show good activity of alcohol oxidase in the cytosolic fraction with different substrates. it was concluded that this microorganisms could be used for decontamination of aquatic habitats polluted with petroleum.
Aislamiento e Identificación de Bacterias y Levaduras Resistentes a Petróleo Isolation and Identification of Petroleum Resistant Bacteria and Yeast
Ismael Acosta-Rodríguez,María G Moctezuma-Zárate,Juana Tovar-Oviedo,Juan F Cárdenas-González
Información Tecnológica , 2011,
Abstract: Se aislaron diferentes microorganismos de varios ríos de la Huasteca Potosina en México, los cuales crecen en presencia de petróleo como única fuente de carbono. Se determinó la actividad de alcohol oxidasa por un método colorimétrico. La bacteria más frecuentemente encontrada fue Pseudomonas aeruginosa (50%) y se encontró solamente una levadura, Candida albicans (6.25%). Además, presentan buena actividad de alcohol oxidasa en la fracción citosólica con diferentes sustratos. Se concluye que estos microorganismos pueden ser utilizados para la eliminación y degradación de petróleo en sitios contaminados. Different microorganisms were isolated from various rivers of the Huasteca Potosina, in Mexico that grow in the presence of petroleum as the sole carbon source. The activity of alcohol oxidase was determined by a colorimetric method. The most common bacteria present in the samples were Pseudomonas aeruginosa (50%) and only one type of yeast was found, Candida albicans (6.25%). Furthermore, they show good activity of alcohol oxidase in the cytosolic fraction with different substrates. It was concluded that this microorganisms could be used for decontamination of aquatic habitats polluted with petroleum.
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