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Open Access Article
1 - Bacterial Bioremediation of Surficial Oil- Contaminated Soil in Tabriz Refinery Campus
Rezvan Agha mohammadi Kamal Siahcheshm Gholamreza Zarrini Ali KadkhodaeeBackground and Objective: Nowadays, the use of bacteria to clean oil pollution from water and soil has been considered by scientists and this method is more economical than other methods and does not cause toxic compounds in the environment. Method: In the present study MoreBackground and Objective: Nowadays, the use of bacteria to clean oil pollution from water and soil has been considered by scientists and this method is more economical than other methods and does not cause toxic compounds in the environment. Method: In the present study, the results of the bioremediation process have been presented to identify the most optimal bacterial isolates of petroleum degraders in physicochemical and textural conditions of contaminated soil of Tabriz refinery. Gas chromatographic analysis with thermal detection (Gc-FID) was used to evaluate the removal rate of hydrocarbons. Findings: The 7 isolates of bacteria were purified in this study. A Pseudomonas isolate was introduced as a strain with the highest efficiency. Discussion and Conclusion: After 30 days, as a result of Pseudomonas and Acinetobacter performance, the amount of TPH in contaminated soil samples was decreased in rate of 65.25 and 42.39 percent, respectively. Based on this investigation, the Bacterial Bioremediation method to clean up contaminated soils by petroleum hydrocarbons due to simplicity of implementation, environmentally friendly, safety and low cost is highly proposed to conduct in other oil refineries in Iran. Manuscript profile -
Open Access Article
2 - Adsorption Kinetics Study of Removal Rhodamine B and Heavy Metals (Cadmium and Cobalt) from Water Using Rhamnolipid Biosurfactant Produced by Pseudomonas Aeruginosa
Fatemeh Diba Babak Mokhtarani Reza PanahiBackground and Objective: An alternative and environmentally friendly method for purifying the environment from pollution is the use of biosurfactant derived from microorganisms. The advantage of biosurfactant is biodegradability, low toxicity, and effectiveness in incr MoreBackground and Objective: An alternative and environmentally friendly method for purifying the environment from pollution is the use of biosurfactant derived from microorganisms. The advantage of biosurfactant is biodegradability, low toxicity, and effectiveness in increasing biological decomposition. Unlike chemical surfactants, surface active substances produced by microbes are easily decomposed, and for this reason, they are very suitable for environmental applications, especially bioremediation. The aim of this study was bioremediation and investigation of the absorption kinetics of heavy metals and Rhodamine B from water by biosurfactant produced from Pseudomonas aeruginosa bacteria.Material and Methodology: In this study, a biosurfactant-producing bacterium that was isolated and identified as Pseudomonas aeruginosa HAK02 from the Kahrizak waste site in the south of Tehran was used to produce a surface bioactive agent to remove pollutants. Zeta potential test was performed to detect the load of biosurfactant produced and used in bioremediation. The amount of color removal was done by UV device and the removal of heavy metals was done by ICP_AES analysis.Findings: Due to the negative charge of the substance, it was used to remove heavy metals and Rhodamine B cationic dye. Biosurfactant produced with Pseudomonas aeruginosa was able to remove 95% rhodamine B, 43% Cd2+, and 35% Co2+. Examining the kinetic model of absorption showed that better correlation with pseudo-second order kinetic model.Discussion and Conclusion: Bioremediation using surfactants to remove heavy metals and dyeing is a fast and environmentally friendly method. This sample is very suitable for the removal of Rhodamine B and has the moderate ability for heavy metals Cd2+ and Co2+. Manuscript profile -
Open Access Article
3 - The Investigation of Effect of Soil Moisture and Temperature on Crude Oil Bioremediation by Pseudomonas Putida
Akbar Ghavidel Sumayyah Naji rad Hossein Ali AlikhaniBackground and Objective: Bioremediation is an approach that exploits the ability of microorganisms to increase the rate and extent of degradation of pollutants and thereby removing pollutants from the environment. The moisture content and temperature are of the main en MoreBackground and Objective: Bioremediation is an approach that exploits the ability of microorganisms to increase the rate and extent of degradation of pollutants and thereby removing pollutants from the environment. The moisture content and temperature are of the main environmental factors affecting growth and activity of microorganisms and accordingly affecting the efficiency of organic pollutant biodegradation.Method: To study the effect of these two factors a factorial experiment was carried out as completely randomized design with three replications. The factors were moisture in three levels (30%, 55% and 80% of Field Capacity), temperature in three levels (25, 30 and 35 degrees of Celsius) and inoculation with bacteria in two levels (with and without inoculation by Pseudomonas putida) which were triplicated.Findings: The results showed that highest biodegradation rate was observed in the treatment with the moisture content of 55% F.C, temperature of 30 degrees of Celsius and inoculation with Pseudomonas putida which was 92.8% and the lowest biodegradation rate was observed in the treatment with the moisture of 30% F.C, temperature of 30 degrees of Celsius and without inoculation which was 42.3%.Discussion and Conclusion: These results shows that the optimization of the environmental conditions in bioremediation process may lead to 50.5% increase in the efficiency of removal. Manuscript profile -
Open Access Article
4 - Isolation and molecular identification of the bacteria involved in removing phosphate from industrial wastewater
Seyed Hossein Hosseini Maryam Tabibi Hamidreza Pordeli Reza Najafpour Fatemeh Karimi Sajjad YazdansetadBackground and Objective: Phosphate is one of the most important contaminants entering recipient waters (rivers, lakes, and seas) by wastewater disposal and causative agent of eutrophication due to the enrichment of aquatic ecosystems. In bioremediation process, the pho MoreBackground and Objective: Phosphate is one of the most important contaminants entering recipient waters (rivers, lakes, and seas) by wastewater disposal and causative agent of eutrophication due to the enrichment of aquatic ecosystems. In bioremediation process, the phosphate-removing bacteria accumulate polyphosphate intracellularly and take it away from the environment. The objective of this study was to isolate and identify the bacteria which remove phosphate from industrial wastewater. Method: In this study, phosphate-removing bacteria were isolated from wastewaters of Aq Qlala industrial park of Golestan province. The isolates were identified based on the creation of clear zone in the bacterial lawn, leading to phosphate removal on the specific agar plate Seperb. Finally, the isolates were identified by macroscopical, microscopical, biochemical, and molecular methods. Findings: In total, 3 out of 30 isolates had high ability in phosphate removal regarding their large clear zone on agar. Molecular identification of isolates by 16S rDNA typing method indicated that the isolates belong to the genera Brevundimonas, Ochrobactrum, Exiguobacterium. Conclusion: Variance analysis using SAS 9.2 software indicated a significant difference in phosphate removal by the isolates. The obtained results demonstrated that the isolates are highly efficient in phosphate removing from wastewater and they are suitable candidates for bioremediation along with other methods. Manuscript profile -
Open Access Article
5 - Microbial fuel cell: a strategy for bioremediation and energy production
Mehran Jafari Samaneh Sedighi KhavidakBackground and Objective: Application of microbial fuel cells (MFC) is a new method for wastewater treatment and environmentally friendly energy production. This technology converts the chemical energy derived from metabolic activity of living organisms into electrical MoreBackground and Objective: Application of microbial fuel cells (MFC) is a new method for wastewater treatment and environmentally friendly energy production. This technology converts the chemical energy derived from metabolic activity of living organisms into electrical energy. Method: A sample of raw wastewater was prepared as a source of microbial fuel cell substrate from the refinery of Yazd city. This study was carried out using a two-compartment bioreactor with wastewater as substrate and microbial flora. The containers were made of glass with a volume of 550 cc. In the anode chamber, under the anaerobic conditions, the wastewater was catalyzed by microbial flora. In the cathode chamber, potassium phosphate buffer was used to maintain the pH of the solution. The positive ions transferring from anode to cathode was done by positive salt bridge system. Findings: The findings showed that the maximum voltage of 1 V was produced during the early days in this reactor. Then gradually the amount of voltage was reduced and wastewater samples were refined to some extent. The highest rate of produced flow was 248 μA, and then the flow rate was decreased. Therefore, the dual role of the reactor in electricity production and wastewater treatment can be explained. Discussion and Conclusion: In this study, wastewater treatment and also electricity production could be performed using a microbial fuel cell based on salt bridge. Manuscript profile -
Open Access Article
6 - Isolation of Toluene Biodegrade Bacteria from ISFAHAN Petrochemical soil
Abbas Akhavanesepahi Elahe Nazer Bagher Yakhchaly Mohammad Reza NazerToluene is one the common and main environmental pollutant factors which often contaminates sites. it is a result of spillages of fuels, solvents or chemicals, also it is one of the major products of petro chemical activities. Because of being highly toxic, it represent MoreToluene is one the common and main environmental pollutant factors which often contaminates sites. it is a result of spillages of fuels, solvents or chemicals, also it is one of the major products of petro chemical activities. Because of being highly toxic, it represents a significant environmental hazard for human and has potential toxicity, carcinogenicity, negative effects on reproduction and mortality rates of aquatic animals. This material is a mutagen as well. Microbial degradation represents the major responsible route for removing these pollutants including fungus, aerobic and anaerobic bacteria. It is important that this component degrades in a high dosage that certain species of bacteria will able to degrade it. 6Toluene-utilizing bacteria is isolated from petrochemical of Isfahan soils .Amongst them one strain tolerant toluene is highly concentrated. They were isolated when bacteria exposed on vapor pressure of toluene (1-100%). They used toluene as sole sources of carbon and energy. This strain was identified by biochemical characteristic and 16S rRNA sequencing as Bacillus. Also amount of deletion of toluene were detected by gas chromatography (GC) during growth of the bacteria. The investigated isolates are considered to have a good potential for application in remediation of toluene contaminated environments and industrial wastewater and soils. Manuscript profile -
Open Access Article
7 - Bioremediation of soil contaminated with light crude oil using Fabaceae family
Bahareh Lorestani Rashin Noori Nasrin KulahchiSoil pollution by petroleum compounds is one of the most common environmental problems, which causes soil contamination during extracting, transferring and refining. Bioremediation is an economic technology that makes use of plants to reduce oil pollution in soil. The a MoreSoil pollution by petroleum compounds is one of the most common environmental problems, which causes soil contamination during extracting, transferring and refining. Bioremediation is an economic technology that makes use of plants to reduce oil pollution in soil. The aim of this study was to evaluate growing ability of Lathyrus sativus, Lens culinaris, Trigonella foenum and Glycyrrhiza glabr of the Fabaceae family in the soil contaminated with light crude oil. Also potential oil removal from soil by these species through bioremediation was shown. In this study, after examining the developmental stage of 4 samples of Fabaceae plant family, potential of removing hydrocarbons from the soil contaminated by light crude oil with different concentrations (1, 2, 3, and 4%) at 40 days in Completely Randomized Design (CRD) was investigated. The result shows that the maximum possibility of pollution reduction is in lathyrus sativus with 73.3% in sample (1%) and the minimum possibility of pollution reduction is in Trigonella foenum with 38.6 in sample (4%). Moreover, Person's correlation coefficient showed that by increasing dry weight of the plant, the amount of pollution reduction in the soil increases. Given the acceptable performance of oil pollution cleanup by these species and economic saving as compared to other methods, the use of this method is recommended for the contaminated areas in Iran. Manuscript profile -
Open Access Article
8 - Bioremediation of anthracene in Siri Island with an emphasis on biosafety
Mozhgan Emtiazjoo Sima Seddighi Marjan EmtiazjooSiri oil region in the Persian Gulf is one the four sites for extracting, refining, and transporting oil. The region is, therefore, exposed to the pollution danger of oil and polycyclic aromatic hydrocarbons (PAHs). In this research, the amounts of PAHs were measured b MoreSiri oil region in the Persian Gulf is one the four sites for extracting, refining, and transporting oil. The region is, therefore, exposed to the pollution danger of oil and polycyclic aromatic hydrocarbons (PAHs). In this research, the amounts of PAHs were measured by GCMS in 8 stations at two transect. Anthracene was observed in most of the research stations and was isolated from the sediment. Then the degradation potential of these bacteria was recognized using well method, biomass measurement, and selective spatial media, and was analyzed with GC. Anthracene degrading microorganisms have been identified with general microbial methods. These microorganisms included: Bacillus sp.PGI, Bacillus sp. PGII, Pseudomonas sp PGIII, and Staphylococcus sp PGIIII. Manuscript profile -
Open Access Article
9 - Glomalin Produced by Arbuscular Mycorrhizal Fungi; A Key Molecule in the Sequestration of Toxic Metals in the Contaminated Soil
Elham MalekzadehAim and scope: In the last few decades, contamination of the environment especially the soil by toxic metals has been increased extremely at worldwide. Entrance of toxic metals into the soil from various sources is a constant and serious threat to the health of plants, MoreAim and scope: In the last few decades, contamination of the environment especially the soil by toxic metals has been increased extremely at worldwide. Entrance of toxic metals into the soil from various sources is a constant and serious threat to the health of plants, animals and human societies. Bioremediation by using of the beneficial soil microorganisms improves the remediation efficiency of the metal contaminated areas and is a suitable alternative method for substitution of current physico-chemical strategies. Methodology: Arbuscular mycorrhizal (AM) fungi are found in virtually all ecosystems worldwide, including in soil contaminated with toxic metals. AM fungi sequestrate toxic metals at fungal intra- and extracellular structures by different mechanisms, so in addition to reduce their toxic effects on host plant prevent from their entrance in the food chain. This study has been addressed the role of glomalin as an important molecule of the cell wall of AM fungi spores and hyphae in soils contaminated by toxic metals. Finding: The results showed that glomalin as a specific product of AM fungi, is present in the role of a heat shock protein as well a critical and main component of spores and hyphal cell wall. Conclusion: Glomalin plays an essential and key role in maintaining and improving the soil health by reducing toxicity and availability of metals for symbiotic partner of AM fungi and other organisms. Manuscript profile -
Open Access Article
10 - Plant growth promoting rhizobacteria and their role in remediation of heavy metal contaminated soils
Mohammad Reza Naderi Rezvan NaderiThe using of plant growth promoting rhizobacteria in order to biological remediation and/or improvement the efficiency of other bioremediation methods of heavy metals contaminated soils has great advantages such as environmental friendly, low cost compared to physical a MoreThe using of plant growth promoting rhizobacteria in order to biological remediation and/or improvement the efficiency of other bioremediation methods of heavy metals contaminated soils has great advantages such as environmental friendly, low cost compared to physical and chemical remediation methods of metal contaminated soils, promotion of soil fertility, raise the biodiversity and etc.. Because of their tolerance to heavy metals, this rhizobacteria are able to adsorb or absorb metal pollutants and also can reduce metals to less toxic forms and thus remediate or immobilize metal. Furthermore, plant growth promoting rhizobacteria have the ability to enhance the plant growth on metal contaminated soils through various mechanisms such as fixation of atmosphere N2, phosphate solubilization, secret of Fe-chelating siderophores, and production of growth promoting hormones like auxin and gibberellin and prevention of excessive synthesis of ethylene by enzyme ACC-deaminase and thus, increase the phytoremediation efficiency of these soils. Hence, in this study, we have a brief review on the role of plant growth promoting rhizobacteria in remediation of heavy metal contaminated soils and also their effect on improve the phytoremediation efficiency of metal pollutants Manuscript profile -
Open Access Article
11 - Isolation and identification of a tellurite resistance bacteria from industry's wastewater at Bioremediation and study optimal conditions increasing the Elimination and bioreduction of tellurite
Mahboubeh Soleimani Sasani Mohammad Reza Zolfaghary Mohammad SoleimaniThe extensive use of tellurium oxyanions, such as Tellurite,in various industries such as textile, tanning and plating ,which are highly toxic to microorganisms and eukaryotes , has increased environmental pollution. Potential application of Tellurite oxyanions bioreduc MoreThe extensive use of tellurium oxyanions, such as Tellurite,in various industries such as textile, tanning and plating ,which are highly toxic to microorganisms and eukaryotes , has increased environmental pollution. Potential application of Tellurite oxyanions bioreduction in resistant bacteria in surroundings can be a valuable tool in biotechnology for Biological removing of tellurite from contaminated areas by microorganisms.84 strains of resistant bacteria to tellurite was separated from industry's wastewater. Tellurite resistance activity was evaluated using the minimum inhibitory concentration (MIC)method, concentration 0/1 to26mM potassium tellurite at 34°C for 7 days by the agar dilution method and QWTmb9 was isolated which able to tolerate and reduction very high concentration of 22 mM. This tolerance to tellurite compared with the threshold concentration of other isolated bacteria is remarkable. In order to evaluate strain's Tellurite removal, colorimetric method using a spectrophotometer and DDTC reagent (sodium-diethyldithiocarbamatetri-hydrate, A340 nm) was used.The effects of various factors on the optimal growth and tellurite removal were investigated conditions Tellurite concentration, pH, temperature, aeration rate and different concentrations of NaCl. Due to the direct connection to oxyanions resistance and resistance to antibiotics, Antibiogram test was conducted.QWTmb9 isolated from wastewater of blanket textile, which maximum removal rates in 24h is in 0.4 concentrations of Tellurite, temperature 35°C, pH7.5 , 100RPM aeration and 170mM NaCl concentration. This strain is resistant to antibiotics penicillin, ampicillin, rifampin, tetracycline, chloramphenicol, neomycin, kanamycin and erythromycin.Gram-negative strains QWTmb9 can be a good candidate for elimination of toxic tellurite in industrial biotechnology. Manuscript profile -
Open Access Article
12 - Isolation and characterization of chromium resistant bacteria for remediation of contaminated effluents
Maryam GhaneThe pollution of the environment with toxic heavy metals is spreading throughout the world along with industrialprogress. Removal of heavy metals needs advance chemical technology and is more expensive too. The cheaperalternative for this is the bioremediation using hea MoreThe pollution of the environment with toxic heavy metals is spreading throughout the world along with industrialprogress. Removal of heavy metals needs advance chemical technology and is more expensive too. The cheaperalternative for this is the bioremediation using heavy metals resistant microorganisms. In this study, 5 heavymetal resistant bacteria were isolated from electroplating effluents collected from Islamshahr. The isolates grewwell on nutrient agar containing 1 mM of chromium (Cr). The resistant isolates were identified on the basis ofmorphological, biochemical and physiological properties. Finally its molecular identity was revealed through16S rRNA analysis. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolates belongto the following genera: Comamonas, Acinetobacter and Acicovorax. The minimum inhibitory concentrations(MICs) of the isolates were determined. All the isolates showed high resistance to chromium with MICs rangingfrom 4-6mM. The results suggest that the isolated strains obtained from effluent owing to its high resistance tochromium have a great potential to be employed for bioremediation of chromium contaminated effluents. Manuscript profile -
Open Access Article
13 - Identification of the resistant bacterial strains from Kermanshah oil wastewater based on molecular 16S rDNA PCR ssequencing and the investigation of their growth in different chromium concentration
Sepideh Khodamoradi Ramin AbiriThe present study was conducted to identify the resistant bacterial strains from Kermanshah oil wastewater based on molecular 16S rDNA PCR sequencing and the investigation of their growth in different chromium concentration. To identify 16S rDNS, 94 samples were isolate MoreThe present study was conducted to identify the resistant bacterial strains from Kermanshah oil wastewater based on molecular 16S rDNA PCR sequencing and the investigation of their growth in different chromium concentration. To identify 16S rDNS, 94 samples were isolated from Kermanshah oil wastewater. Sequencing the best strain for most removal was conducted. Bactria were identified by morphology, Gram staining, Biochemical tests, Standard microbiology. Cr (VI) was incubated in the concentrations of 25, 50, 100 and 150 mg/ml for 96 h. The maximum Cr biosorption (0.35 ppm) was observed at 28°C and a pH=7.5-8. Biological oxygen demand was 126-530. The most isolates had a need from 7.2-7.90 for chemical oxygen demand. Based on obtained results, Klebsiella variicola, Bacillus aerius, Bacillus stratosphericus and Lysinibacillus fusiformis were most resistant strains. Bacteria growth was higher in control, 25, 50, 100 and 150 mg, respectively. All the bacteria showed a fix growth after 72h. Considering high resistant of Klebsiella variicola, Bacillus aerius, Bacillus stratosphericus and Lysinibacillus fusiformis, the strains can be used for bioremediation of chromium and decreasing aontaminations, especially in oil refinery. Manuscript profile -
Open Access Article
14 - The fate of pesticides in the environment and its biological purification
Ahmad Asl hashemi safari Gholamhossein Leila Tarverdizad sahra SakhaiefarPesticides are substances in liquid, solid or gas form that are used to destroy pests. Some of these pests that are not liked by humans are insects, weeds and microbes that destroy plants. The negative effect of pesticides on the environment has been fully proven, and t MorePesticides are substances in liquid, solid or gas form that are used to destroy pests. Some of these pests that are not liked by humans are insects, weeds and microbes that destroy plants. The negative effect of pesticides on the environment has been fully proven, and the resistance of pesticides in the environment and their non-degradation have endangered the lives of many living organisms.Persistent organic pollutants (POPs) are chemical substances that remain in the environment for a relatively long time and upon entering the food chain, accumulate in living tissues and have adverse effects on human health and the environment. In general, these compounds are produced by human activities in different ways.The most famous persistent organic pollutants include chlorine, aldrin, crodan, dedet, dieldrin, dioxin, andrin, norans, heptachlor, hexachlorobenzene, Mirex, toxaphene, polychloride, biphenyls pesticides.So that by optimal and standard use and reducing the use of such chemical poisons (use of biological control methods) we can reduce the harmful effects on the environment. Manuscript profile -
Open Access Article
15 - Effects of pesticides in the environment and its biodegradation
Ahmad Asl hashemi Leila Tarwardizadeh Sahra SakhaifarPesticides are widely used to prevent unwanted attacks of pests on plants and agricultural fields. The uniqueness of their chemical structure or their interaction with the environment determines the nature of pesticides. In most cases, farmers and consumers of these pro MorePesticides are widely used to prevent unwanted attacks of pests on plants and agricultural fields. The uniqueness of their chemical structure or their interaction with the environment determines the nature of pesticides. In most cases, farmers and consumers of these products, although they know their serious effects, still cannot limit their consumption. Pesticides have harmful effects on soil and human ecosystems that affect molecules, tissues and biological organs and cause acute or chronic disorders. These disorders affect people of all ages, including during pregnancy. These pollutants affect aquatic systems when released. Water molecules in the river are affected by the accumulation of these toxic pollutants with alkaline pH and heavy metals, which can negatively affect the health of plants and animals. This article discusses the scientific literature on the various modification technologies available for safer pesticide use. The use of microorganisms and biological methods for the decomposition of chemical substances in the soil is monitored. However, the effectiveness of this method in the future to save the environment is debatable. Manuscript profile -
Open Access Article
16 - The growth of Matricaria chamomilla L. affected by cadmium and lead in greenhouse and field conditions
Mohammad bagheri Hamid Reza Javanmanrd Mohammad Reza Naderi The use of medicinal plants in contaminated soils with heavy metals is of significance for the bioremediation of the environment and for plant growth. The effects of cadmium (Cd) and lead (Pb) on the growth of roots and aerial parts, and the number of flowers in M More The use of medicinal plants in contaminated soils with heavy metals is of significance for the bioremediation of the environment and for plant growth. The effects of cadmium (Cd) and lead (Pb) on the growth of roots and aerial parts, and the number of flowers in Matricaria chamomilla L. were investigated in greenhouse and field conditions using 10-kg pots containing polluted soil with Cd (0, 10, and 40 mgkg-1) and Pb (0, 60 and 180 mgkg-1) in 2018-2019 in Isfahan (Khorasgan) Islamic Azad University. The effects of the experimental treatments including metal concentration was significant at 5% level, growth stage and location, plant tissue and their interactions significantly affected plant growth (dry weight) was significant at 1% level. Increasing Cd and Pb concentrations decreased number of flowers in the field and increased it in the greenhouse. Plant growth significantly decreased by increasing heavy metal concertation was significant at 5% level as at the first, second and third contamination levels, it was equal to 480.39, 416.00, and 399.33 g, respectively. The highest plant growth was resulted at flowering (500.78) and tillering (511.67 g), significantly at 5% level higher than that of stemming (283.28 g). Compared with Pb (407.44 g), increasing Cd concentration, resulted in significantly at 5% level higher reduction (333.11 g) of plant growth. It is possible to grow Matricaria chamomilla L. in heavy metal polluted soils for the bioremediation of the environment. Manuscript profile -
Open Access Article
17 - Isolation and phylogenetic analysis of indigenous oil-degrading bacteria from soil of Karoon area in Ahvaz
Mohammad Hossein Arash Assadirad Mahnaz Mazaher Asadi Hamid Rashedi Taher Nejadsattari Background & Objectives: Bioremediation is the promising technology for the treatment of the contaminated sites since it is cost-effective and will lead to complete mineralization. This study was aimed to isolation and phylogenetic identification of indigeno More Background & Objectives: Bioremediation is the promising technology for the treatment of the contaminated sites since it is cost-effective and will lead to complete mineralization. This study was aimed to isolation and phylogenetic identification of indigenous oil-degrading bacteria from soil of Karoon area in Ahvaz. Materials & Methods: The crude oil contaminated soil of Karoon area in Ahvaz was sampled accidentally and under sterile condition. The amount of absorbable phosphorus was determined using Olson method and also, carbon, hydrogen and nitrogen by CHN meter device. Mineral salt medium containing 2% crude oil was used for isolation of oil eating bacteria. Following sieving the soil samples, the total carbon content of the soils were analysed by gas chromatography. Biochemical tests and PCR method were used to identify the dominant bacteria. Results: In this study, 44 bacterial strains were isolated, among them 20 isolates in the first and one in the second screening methods were selected, which was nominated as S31.This strain belonged to Bacillus licheniformis. The growth of the selected isolate in the media with 2% crude oil was better than the standard strain and remediated 84% of the crude oil in 30 days incubation time at about 30o C. Conclusion: The selected Bacillus could use 2% of crude oil as source of carbon and energy and we suggest further studies on this bacterium in bacterial consortia. Manuscript profile -
Open Access Article
18 - Bioremediation of mineral mercury via construction of recombinant vector pET21a(+)-merA
Hamideh Baghi Sefidan Alireza TarinejadBackground & Objectives: Inorganic mercury entrance into the environment through industry and agriculture is one of the most serious environmental hazards in the country. Microbial bioremediation is considered as one of the practical solutions to clean up pollutant MoreBackground & Objectives: Inorganic mercury entrance into the environment through industry and agriculture is one of the most serious environmental hazards in the country. Microbial bioremediation is considered as one of the practical solutions to clean up pollutant ions from the environment. The present study was conducted to construct a recombinant vector including merA gene, and also to investigate its expression in order to clean up mercury. Material & Methods: merA gene from mercury resistance bacterial genome was isolated, and subsequently cloned into the pET21a(+) expression vector. Confirmation of cloning target gene was achieved by PCR and restriction enzyme digestion. Then pET21a(+)-merA recombinant vector was cloned into E.coli strain BL21. In order to assess increased resistance to mercury in recombinant bacteria, and the functionality of the enzyme produced by the recombinant vector, the growth rate of recombinant BL21 E. coli strains to contain merA gene, and without it was measured in a medium containing mercury for 48 hours. Results: The results showed that the growth of E. coli strains without merA gene was strongly affected after introducing mercury into the media till 12 hours, and bacteria would not be able to grow at 10 ppm and 20 ppm mercury levels. However, transformed bacteria with pET21a(+)-merA vector showed suitable growth in mercury-containing media. SDS-PAGE analysis of recombinant bacterial proteins on acrylamide gel showed the highest MerA (62KDa) expression following 16 hours induction with 1mM IPTG at 37ºC. Conclusion: Overall, the growth ability of merA- containing recombinant bacteria reflects the action of MerA protein in transformed bacteria. Furthermore, increasing the resistance of recombinant bacteria to the mercury indicates that environmental heavy metal pollutants can be cleaned up properly through the construction of recombinant vectors. Manuscript profile -
Open Access Article
19 - Study on lead biosorption by lead resistant bacteria isolated from industrial wastewater of plants in AqQala industrial park
Mohsen Ebrahimi Ania Ahani AzariBackground & Objectives: Lead is a heavy metal and persistent pollutant in the environment that enters through industrial wastewaters. The aim of this study was to isolate lead resistant bacteria from the industrial wastewaters, and to study the lead absorptio MoreBackground & Objectives: Lead is a heavy metal and persistent pollutant in the environment that enters through industrial wastewaters. The aim of this study was to isolate lead resistant bacteria from the industrial wastewaters, and to study the lead absorption by the isolated bacteria. Materials & Methods: This descriptive study was performed on three wastewater samples. Nutrient agar medium containing different concentrations of lead acetate were used to isolate the lead resistant bacteria. Overall, 28 colonies were selected and their characteristics were determined. Of these, six colonies with the highest lead resistance were selected. The rate of lead absorption of these strains was measured using atomic absorption spectrophotometry. Four strains with higher lead absorption was identified using molecular method. Results: 78.5% of the isolated resistant bacteria were Gram positive and 21.5% of the bacteria were Gram negative bacteria. Biochemical tests showed that 46.5% of the isolates were belonged to Bacillus sp. Of these, T5 had the highest lead absorption. Also, sequencing results revealed that the selected isolates are belong to Escherichia coli strain 789, Enterobacter cloacae strain GGT036, Bacillus tequilensis strain KM30 and Kurthia sp. VITA1 (T5). Conclusion: The result of this study showed that the bacteria isolated from lead-containing wastewaters are highly potent for removal of this metal from polluted environments, and therefore can be appropriate candidates for bioremediation and biological treatment. Manuscript profile -
Open Access Article
20 - Bioremediation of both mineral and organic mercury via the construction of recombinant vector pET28a(+)-merA-merB
Hamide Baghi Sefidan Alireza TarinejadBackground & Objectives: Mercury due to stability and the high cost of conventional refinement methods is a major environmental problem in the world. Biological methods such as the use of bacterial-based bio-reactors or their enzymes are one of the bioremediation me MoreBackground & Objectives: Mercury due to stability and the high cost of conventional refinement methods is a major environmental problem in the world. Biological methods such as the use of bacterial-based bio-reactors or their enzymes are one of the bioremediation methods. MerA and MerB bacterial enzymes are used to decompose organic and inorganic compounds of mercury. This study was designed to clone merA and merB genes into the pET28a (+) expression vector for the production of MerA and MerB active enzymes.Material & Methods: At first merA and merB genes were isolated from mercury- resistant bacterial genome and subsequently cloned into pET28a(+) expression vector. Confirmation of cloning the target gene was achieved by PCR and restriction enzymes. Then pET28a(+)-merA-merB recombinant vector was transformed into E.coli strain BL21. To assess resistance to inorganic and organic mercury by transformed bacteria and the functionality of the enzyme produced by a recombinant vector, the growth of E.coli strain BL21 containing the recombinant vector and without it were measured by adding mercury into the environment during 48 h.Results: Recombinant bacterial growth in medium containing different levels of inorganic and organic mercury was measured at different times. The result showed that the growth of E. coli containing no target gene in the vector was affected after introducing mercury into the medium till 12 hours so that bacteria would not be able to grow at 10 and 20ppm mercury concentrations. However, transformed bacteria with pET28a(+)-merA-merB vector showed suitable growth in a mercury-containing medium. The SDS-PAGE analysis of extracted proteins from transformed bacteria with pET28a(+)-merA-merB vector on 12.5% acrylamide gel showed the highest MerA (62kDa) and MerB enzymes (23kDa) expression following 16 hours induction with 1mM IPTG at 37ºC.Conclusion: Growth ability of transformed E.coli with recombinant vector indicates MerA and MerB proteins function in transformed bacteria. Furthermore, increasing resistance of recombinant bacteria to inorganic and organic mercury indicates that heavy metal pollution in the environment can be cleaned up with proper management through the construction of a recombinant vector. Manuscript profile -
Open Access Article
21 - Crude oil and polycyclic aromatic hydrocarbons (PAHs) biodegradation by Exophiala sp. UTMC 5043
Farahnaz Akbarzadeh Hamid Moghimi Shamsozoha Abolmaali Javad HamediBackground & Objectives: Today, crude oil products are one of the most widely used chemicals in the world. Daily, large volumes of crude oil and their derivatives are poured into the environment. The aim of this study was to isolate and evaluate Iranian indigenous y MoreBackground & Objectives: Today, crude oil products are one of the most widely used chemicals in the world. Daily, large volumes of crude oil and their derivatives are poured into the environment. The aim of this study was to isolate and evaluate Iranian indigenous yeast strains for the purpose of bioremediation of crude oil pollutants.Materials & Methods: Soil samples were collected from different oil-contaminated areas of Iran. The samples were cultured for 14 days on Bushnell Hass medium containing 0.5 % crude oil and 100 mg l-1 tetracycline. The crude oil degradation was measured by TPH assay at 420 nm. Removal of 100 ppm of phenanthrene, anthracene, and pyrene as model polycyclic aromatic hydrocarbons (PAHs) was studied using HPLC method. The superior yeast strain was identified by ITS gene sequencing and alignment in the NCBI database.Results: Totally, 47 yeast strains were isolated. TPH assay showed that FA14 isolate with 89% degradation rate within 14 days was the most powerful isolate in the removal of PAHs. ITS gene sequencing followed by alignment in NCBI indicated that FA14 belongs to the genus Exophiala sp., showing 99% similarity. Furthermore, the results indicated that within 14 days phenanthrene, anthracene, and pyrene were degraded by FA14 with the rate of 97.67 %, 57.0 %, and 95.38 %, respectively.Conclusion: Our results showed that Exophiala sp. has a high ability for biodegradation of crude oil and PAHs. Therefore, it could be introduced as a potent strain for bioremediation of oil-contaminated soil samples. Manuscript profile -
Open Access Article
22 - Bio-remediation of sulfuric compounds from the ceramic wastewater using indigenous bacteria and Thiobacillus thioparus
Mahtab Taherian Fatemeh Ardestani Mehdi ParviniBackground & Objectives: Sulfide compounds of ceramic industries wastewater cause water pollution as well as plants and aquatic destruction. This study was aimed to evaluate sulfide compounds removal from ceramic industries wastewater by Thiobacillus thioparus MoreBackground & Objectives: Sulfide compounds of ceramic industries wastewater cause water pollution as well as plants and aquatic destruction. This study was aimed to evaluate sulfide compounds removal from ceramic industries wastewater by Thiobacillus thioparus and indigenous wastewater bacterial isolates. Materials & Methods: Indigenous bacterial strains were proliferated at pH of 7, the temperature of 25oC, agitation speed of 200 rpm and an aeration rate of 100 mL min-1 in a 2 L bioreactor for 15 consecutive cycles. Sulfide compounds removal function of T. thioparus and indigenous bacterial strains along with the effect of pH and initial sulfide concentrations were investigated. Results: The results showed a thiosulfate removal rate of 250 mg sulfide L-1 h-1, a thiosulfate conversion percentage of 100% and a thiosulfate oxidation time of 44 min following 8 consecutive cycles. The sulfide removal rate of T. thioparus and ceramic wastewater indigenous bacteria was obtained as 246.5 and 276.5 mg sulfide L-1 h-1, respectively. Sulfide removal rate by proliferated bacteria decreased from 250 at pH of 7 to 230 and 180 mg sulfide L-1 h-1 at pH of 8 and 9, respectively. Bacterial isolates had an acceptable function in sulfide concentration of 3000 mg L-1, as well. Sulfide removal ability of T. thioparus isolates was decreased by 2.5 and 4 folds, when pH changed from 7 to 8 and 9, respectively. This bacterial strain was not able to tolerate high sulfide concentrations. Conclusion: The results showed that bacteria isolated from ceramic industries wastewater have a higher capability of sulfide compounds removal as compared to T. thioparus isolates. Manuscript profile -
Open Access Article
23 - Isolation and characterization of heavy metal resistant halophilic and halotolerant bacteria from the Lut desert
Nazanin Tavoosi Abbas Akhavan Sepahi Mohammad Ali Amoozegar Vahid KiarostamiBackground & Objectives: Heavy metal pollution has increased worldwide. Bioremediation of toxic heavy metals in saline environments with conventional microbiological treatment processes is not feasible. Therefore, the use of halophilic and halotolerant bacteria MoreBackground & Objectives: Heavy metal pollution has increased worldwide. Bioremediation of toxic heavy metals in saline environments with conventional microbiological treatment processes is not feasible. Therefore, the use of halophilic and halotolerant bacteria need to be considered for the remediation of saline ecosystems. This study aimed to isolate and characterize toxic heavy metal-resistant and halophilic/halotolerant bacteria from the Lut desert.Materials & Methods: After sampling, halophilic/halotolerant bacteria were isolated on Moderate Halophilic media. Morphological and biochemical characterizations of isolates were carried out. Each isolate's heavy metal resistance was identified by an agar dilution method and the Minimum Inhibitory Concentrations (MIC ) of each heavy metal was determined. Then, sixteen strains were randomly selected and subjected to 16S rRNA gene identification.Results: The least toxicities were found with selenite and arsenate on 74 selected isolates, while mercury exhibited the highest toxicity. The maximum MIC values of cadmium, copper, and chromium were the same. Although, the MIC value of zinc was significantly less. The remarkable resistance toward lead, selenite, and arsenate was reported. Phylogenetic analysis revealed that most strains belong to the Bacillaceae family and Bacillus genus. Conclusion: Selected halophilic/halotolerant bacteria from the Lut desert had considerable resistance to heavy metals. Therefore, these strains could be considered for further investigations of the mechanisms involved in heavy metal resistance of halophilic and halotolerant bacteria or for bioremediation of polluted saline environments. Manuscript profile -
Open Access Article
24 - Bioremediation potential of indigenous gram-positive bacteria isolated from contaminated soil with polycyclic aromatic hydrocarbons
Somayeh Scandari Mehran Hoodaji Arezo Tahmourespour Atoosa AbdollahiBackground and Objectives: Polycyclic aromatic hydrocarbons (PAHs) were extensively spread in the environment and are regarded as one of the mutagenic and carcinogenic agents on living creatures. Among the vast variety of procedures for the elimination of contaminatio MoreBackground and Objectives: Polycyclic aromatic hydrocarbons (PAHs) were extensively spread in the environment and are regarded as one of the mutagenic and carcinogenic agents on living creatures. Among the vast variety of procedures for the elimination of contamination, biological removal is capable of transmuting pollutants into innocuous and nontoxic substances using less amount of energy, chemicals and time. The study was aimed at evaluating the possibility of growth of the indigenous bacteria isolated from oil-polluted soils, in the presence of PAH compounds in the laboratory, and also identifying them by using the method of PCR. Material and Methods: Specimens of the research were isolated from environmental gasoline and oil-polluted soils from the Isfahan City refinery. Initially, the native bacteria were separated from the contaminated soil with such compounds by utilizing a basic medium containing the concentration of 12.8 mg/l in 16 PAH compounds. Then, those bacteria which were able to grow and reproduce in the presence of the compounds identified through biochemical experiments and determination of genome sequence and consequently registered as new species. Results: The results obtained in the study substantiated that approximately 13.3% of the total heterotrophic bacteria possess a degradable ability of the hydrocarbons. After the evaluation of biochemical tests and gene sequencing, it was disclosed that the isolated indigenous bacteria belonged to Bacillus licheniformis ATHE9, Bacillus mojavensis ATHE13 and a particular species of Bacillus (ATHE10). Conclusion: The results of the present research verify the importance and proficiency of the native bacteria in the terms of the elimination of PAHs pollutions in contaminated areas. Manuscript profile -
Open Access Article
25 - Biodegradation of fluoranthene by indigenous bacteria isolated from sediments of mangrove forests in Persian Gulf
Farshid Kafilzade Parvin Amiri Atefeh Rezaei Narges AhmadiBackground and Objectives: Polycyclic aromatic hydrocarbons are a group of organic compounds with two or more aromatic rings, and approximately 90 percent of these compounds are carcinogen. Although there are different methods to clear such contaminants from environment MoreBackground and Objectives: Polycyclic aromatic hydrocarbons are a group of organic compounds with two or more aromatic rings, and approximately 90 percent of these compounds are carcinogen. Although there are different methods to clear such contaminants from environment, microorganisms are more effective and more cost friendly. This study was designed to isolate indigenous microorganisms which are able to biodegradation fluoranthene from sediments of mangrove forests in Persian Gulf and to evaluate their biodegrading ability on fluoranthene. Materials and Methods: This sectional study was performed on the sediment samples collected from Persian Gulf mangrove. The bacteria were counted in two series of media; one containing fluoranthene and another one without any contaminants. The degrading bacteria were isolated on two basic mineral media (MSM and MSM Agar). The degradation ability were assayed based on High pressure liquid chromatography (HPLC). Results: The total number of bacteria grown on the medium without Fluoranthene was significantly more than those contaminated with Fluoranthene (cfu/g). Among the isolated bacteria Bacillus circulance, Alcaligens fecalis, Entrobacter, Listeria and Staphylococcus showed the highest ability to degrade Fluoranthene. Bacillus circulance and Alcaligens fecalis showed the most biodegrading activity and growth at the presence of fluoranthene (73.4% and 71%, respectively). Conclusion: Results of this study indicate that there are many fluoranthene degrading bacteria in Persian Gulf mangrove sediments. Manuscript profile -
Open Access Article
26 - Assessment Bioremediation of Contaminated Soils to Petroleum Compounds and Role of Chemical Fertilizers in the Decomposition Process
H. Parvizi Mosaed S. Sobhan Ardakani M. Cheraghi -
Open Access Article
27 - Phytoremediation potential of black nightshade in cadmium contaminated soils in hydroponic system
Fatemeh Ebrahimi Amin Baghizadeh Shahram PourseyediCadmium is a heavy metal causing oxidative stress in plants. The study objective was to determine phytoremediation potential of black nightshade in cadmium contaminated culture medium. The experiment was carried out under hydroponic conditions with five cadmium chl MoreCadmium is a heavy metal causing oxidative stress in plants. The study objective was to determine phytoremediation potential of black nightshade in cadmium contaminated culture medium. The experiment was carried out under hydroponic conditions with five cadmium chloride concentrations of 0, 100, 200, 400 and 600 mM based on completely randomized design in three replications. Root length, plant height, plant fresh and dry weight, leaf area, cadmium uptake rate and total chlorophyll were recorded. Cadmium application decreased plant dry weight, leaf area and total chlorophyll and increased root length, plant height and cadmium uptake. Cadmium concentrations up to 400 mM caused cadmium uptake increment in plants. Black nightshade kept phytoremediation potential even at 600 mM cadmium concentration. These changes in morph-physiological traits are for cadmium stress management causing survivability of plant against these conditions and black nightshade could be effective in environment hygiene by cadmium accumulation in its tissues. Therefore, black nightshade might be recommended as a cadmium hyper-accumulator plant in industrial cadmium contaminated soils. Manuscript profile
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