Papers by Ahmad Pourbabaee
Geomicrobiology Journal, 2017
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Http Dx Doi Org 10 1080 10889868 2014 917269, Jul 1, 2014
ABSTRACT The primary objective of this study was the isolation of low-density polyethylene (LDPE)... more ABSTRACT The primary objective of this study was the isolation of low-density polyethylene (LDPE)-degrading microorganisms. Soil samples were obtained from an aged municipal landfill in Tehran, Iran, and enrichment culture procedures were performed using LDPE films and powder. Screening steps were conducted using linear paraffin, liquid ethylene oligomer, and LDPE powder as the sole source of carbon. Two landfill-source isolates, identified as Lysinibacillus xylanilyticus XDB9 (T) strain S7-10F and Aspergillus niger strain F1-16S, were selected as super strains. Photo-oxidation (25 days under ultraviolet [UV] irradiation) was used as a pretreatment of the LDPE samples without pro-oxidant additives. The PE biodegradation process was performed for 56 days in a liquid mineral medium using UV-irradiated pure LDPE films without pro-oxidant additives in the presence of the bacterial isolate, the fungal isolate, and the mixture of the two isolates. The process was monitored by measuring the fungal biomass, the bacterial growth, and the pH of the medium. During the process, the fungal biomass and the bacterial growth increased, and the pH of the medium decreased, which suggests the utilization of the preoxidized PE by the selected isolates as the sole source of carbon. Carbonyl and double bond indices exhibited the highest amount of decrement and increment, respectively, in the presence of the fungal isolate, and the lowest indices were obtained from the treatment of a mixture of both fungal and bacterial isolates. Fourier transform infrared (FT-IR), x-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses showed that the selected isolates modified and colonized preoxidized pure LDPE films without pro-oxidant additives.
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Archives of Agronomy and Soil Science, 2016
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Communications in Soil Science and Plant Analysis, 2016
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Phosphorus is an important element in different organic and inorganic compounds. In case, vermico... more Phosphorus is an important element in different organic and inorganic compounds. In case, vermicompost and rock phosphate which are two organic and inorganic sources of phosphorus are used as suitable carriers for bacteria preservation, after inoculation at the beginning of seeds germination, it is possible that this material produces more successful colonization. The purpose of this research was to study the survival of bacteria Pseudomonas florescense as one of phosphate solubilizing bacteria on different organic and inorganic carriers including rock phosphate, vermicompost, perlite, bentonite and different formulations of them. In order to study the effects of different carriers on survival, after determination of their physical and chemical specifications, carriers were inoculated by bacteria and inoculants were maintained in controlled conditions for 180 days. Bacteria populations were measured at times 0, 15, 30, 60, 90, 120, 150 and 180 days by CFU method. The results of bact...
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Modern Multidisciplinary Applied Microbiology, 2006
... [6] Karapinar, K., Karagi, F., Mcmullan, G., and Marchant, R. Biotechnology Lett, 22,1179-118... more ... [6] Karapinar, K., Karagi, F., Mcmullan, G., and Marchant, R. Biotechnology Lett, 22,1179-1181( 2000). [7] Arslan, I. Journal of Hazardous materials, Ð’ 85, 229-241(20001). ... [9] Nigam, P., Mcmullan, G., Banat, I. and Marchant, R. Biotechnol Lett, 18, 117-120(1996). ...
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Bioremediation Journal, 2014
ABSTRACT The primary objective of this study was the isolation of low-density polyethylene (LDPE)... more ABSTRACT The primary objective of this study was the isolation of low-density polyethylene (LDPE)-degrading microorganisms. Soil samples were obtained from an aged municipal landfill in Tehran, Iran, and enrichment culture procedures were performed using LDPE films and powder. Screening steps were conducted using linear paraffin, liquid ethylene oligomer, and LDPE powder as the sole source of carbon. Two landfill-source isolates, identified as Lysinibacillus xylanilyticus XDB9 (T) strain S7-10F and Aspergillus niger strain F1-16S, were selected as super strains. Photo-oxidation (25 days under ultraviolet [UV] irradiation) was used as a pretreatment of the LDPE samples without pro-oxidant additives. The PE biodegradation process was performed for 56 days in a liquid mineral medium using UV-irradiated pure LDPE films without pro-oxidant additives in the presence of the bacterial isolate, the fungal isolate, and the mixture of the two isolates. The process was monitored by measuring the fungal biomass, the bacterial growth, and the pH of the medium. During the process, the fungal biomass and the bacterial growth increased, and the pH of the medium decreased, which suggests the utilization of the preoxidized PE by the selected isolates as the sole source of carbon. Carbonyl and double bond indices exhibited the highest amount of decrement and increment, respectively, in the presence of the fungal isolate, and the lowest indices were obtained from the treatment of a mixture of both fungal and bacterial isolates. Fourier transform infrared (FT-IR), x-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses showed that the selected isolates modified and colonized preoxidized pure LDPE films without pro-oxidant additives.
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Paddy and Water Environment, 2013
ABSTRACT The aim of this study was to evaluate the impacts of land leveling on some of soil prope... more ABSTRACT The aim of this study was to evaluate the impacts of land leveling on some of soil properties. Land leveling as an effective strategy for paddy land management is one of the most important programs run by the Ministry of Jihad-Agriculture in Guilan province, northern part of Iran. Precise land leveling improves irrigation application, fertilization efficiency, and uniform soil moisture for germination. Also, it increases yields and cultivable lands and reduces delivery losses. Running land-leveling projects, however, leads to such disadvantages as severe soil alteration and consequently disruptions to the soil physical, chemical, and biological properties. Based on statistical analysis, on the one hand land, leveling led to significant increases (P < 0.01) in bulk density, clay percentage, and EC, and on the other hand, it resulted in significant decreases (P < 0.01) in the soil organic matter, silt percentage, NPK, pH, soil respiration, bacterial community, and microbial biomass carbon. Microscopic images of buried slides indicated that there was a reduction in the soil microorganism communities and diversities as well. With regard to the management of paddy fields, despite beneficial impacts of land leveling, the results indicate that due to malperformance of the project, which is a consequence of the use of inappropriate machinery and/or nonremoval of surface soil and its re-diffusion, most of soil-desirable properties are reduced and are not revitalized even after 4 years.
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PLoS ONE, 2013
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Microbiology, 2013
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Biotechnology and Bioengineering, 2006
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Bioresource Technology, 2007
Studies were carried out on the decolorization of textile azo dyes by newly isolated halophilic a... more Studies were carried out on the decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria. Among the 27 strains of halophilic and halotolerant bacteria isolated from effluents of textile industries, three showed remarkable ability in decolorizing the widely utilized azo dyes. Phenotypic characterization and phylogenetic analysis based on 16S rDNA sequence comparisons indicate that these strains belonged to the genus Halomonas. The three strains were able to decolorize azo dyes in a wide range of NaCl concentration (up to 20%w/v), temperature (25-40 degrees C), and pH (5-11) after 4 days of incubation in static culture. They could decolorize the mixture of dyes as well as pure dyes. These strains also readily grew in and decolorized the high concentrations of dye (5000 ppm) and could tolerate up to 10,000 ppm of the dye. UV-Vis analyses before and after decolorization and the colorless bacterial biomass after decolorization suggested that decolorization was due to biodegradation, rather than inactive surface adsorption. Analytical studies based on HPLC showed that the principal decolorization was reduction of the azo bond, followed by cleavage of the reduced bond.
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Introduction: Sulfur oxidizing bacteria are important in agriculture. The aim of this study was t... more Introduction: Sulfur oxidizing bacteria are important in agriculture. The aim of this study was to identify the sulfur oxidizing bacteria in Sarcheshmeh (Kerman, Iran) agricultural soil.
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Papers by Ahmad Pourbabaee