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Papers by M. Hassanshahian

Research paper thumbnail of Paper: CLONING AND GENE EXPRESSION OF CYTOCHROME P450 GENE FROM ALCANIVORAX BORKUMENSIS BACTERIUM

Research paper thumbnail of Paper: DEGRADATION OF ALKANES IN CONTAMINATED SITES

Research paper thumbnail of Paper: ANTIMICROBIAL ACTIVITY OF TRACHYSPERMUM AMMI ESSENTIAL OIL AGAINST HUMAN BACTERIAL

Research paper thumbnail of SCREENING, IDENTIFICATION AND EVALUATION OF PROBIOTIC POTENTIAL OF ENTEROCOCCI IN TRADITIONAL DAIRY PRODUCTS OF SABZEVAR

Research paper thumbnail of Antibacterial Effect of Ethanol Extract of Camellia Sinensis L against Escherichia Coli

Research paper thumbnail of Isolation and characterization of phenol degrading bacteria from Persian Gulf

This study investigated the aerobic degradation of phenol by yeast strains isolated from an oil r... more This study investigated the aerobic degradation of phenol by yeast strains isolated from an oil refinery wastewater from the Northeast of Brazil. The samples displayed low fungal diversity, as only yeast colonies were detected on Sabouraud dextrose agar containing chloramphenicol 0.05% (w/v). Among the isolates, three yeast strains were selected to be evaluated for their potential for degrading high phenol concentrations. These species were identified through morphological and biochemical characteristics as Candida tropicalis, C. rugosa, and Pichia membranaefaciens. Although the strains were able to degrade the phenol concentration present in the wastewater, which was 7 mg l À1 , only C. tropicalis was capable of growing at high concentrations of phenol such as 500 mg l À1 and 1,000 mg l À1 in a mineral medium containing this pollutant as the only carbon source. C. rugosa and P. membranaefaciens were inhibited in the presence of 500 mg l À1 of phenol. However, a longer incubation time was needed for C. tropicalis strain to degrade 1,000 mg l À1 of phenol compared to the time required to degrade 500 mg l À1 . Moreover, the strain released a significant amount of polysaccharide biosurfactant in the medium probably to minimize the toxic effect of the high phenol concentration. When challenged with 1,500 and 2,000 mg l À1 of phenol, C. tropicalis was unable to grow at the tested conditions. The results indicate that this strain of C. tropicalis can be considered both a good phenol-degrader and biosurfactant-producer. Application of this strain might be useful in bioremediation activities or treatment of phenol-polluted wastewater.

Research paper thumbnail of Isolation and characterization of crude-oil-degrading bacteria from the Persian Gulf and the Caspian Sea

Marine Pollution Bulletin, 2012

Twenty-five crude-oil-degrading bacteria were isolated from oil-contaminated sites in the Persian... more Twenty-five crude-oil-degrading bacteria were isolated from oil-contaminated sites in the Persian Gulf and the Caspian Sea. Based on a high growth rate on crude oil and on hydrocarbon degradation ability, 11 strains were selected from the 25 isolated strains for further study. Determination of the nucleotide sequence of the 16S rRNA gene showed that these isolated strains belonged to genera Acinetobacter, Pseudomonas, Gordonia, Rhodococcus, Cobetia, Halomonas, Alcanivorax, Marinobacter and Microbacterium. Among the 11 isolates, strains BS ( Acinetobacter calcoaceticus, 98%) and PG-12 ( Alcanivorax dieselolei, 98%) were the most effective in degrading crude oil. Rate of crude-oil degradation of 82% (isolate BS) and 71% (isolate PG-12) were observed after 1 week of cultivation in mineral medium. These strains had high emulsification activity and biosurfactant production. GC-MS analysis showed that A. dieselolei PG-12 can degrade different alkanes in crude oil. Screening of the distribution of the alkane hydroxylase gene in 25 isolates in relation to the source of isolation indicated that the group (II) alkane hydroxylase is prevalent in the Caspian Sea, but in the Persian Gulf, the frequency of the group (III) alkane hydroxylase gene is greater than that of the group (II) alkane hydroxylase gene.

Research paper thumbnail of Isolation and characterization of alkane degrading bacteria from petroleum reservoir waste water in Iran (Kerman and Tehran provenances)

Marine Pollution Bulletin, 2013

and sharing with colleagues.

Research paper thumbnail of Bioremediation (bioaugmentation/biostimulation) trials of oil polluted seawater: A mesocosm simulation study

Marine Environmental Research, 2014

Bioaugmentation (amendment with selected bacterial strains) and/or biostimulation (nutrients addi... more Bioaugmentation (amendment with selected bacterial strains) and/or biostimulation (nutrients addition and/or air supply) are relatively new fields in environmental microbiology for preventing pollution and cleanup contamination. In this study, the efficiency of application of bioaugmentation/biostimulation treatments, for recovery of crude oil-polluted seawater, was evaluated. Three different series of experiments were performed in a "Mesocosm Facility" (10.000 L). Natural seawater was artificially polluted with crude oil (1000 ppm) and was amended with inorganic nutrients (Mesocosm 1, M1), inorganic nutrient and an inoculum of Alcanivorax borkumensis SK2 T (Mesocosm 2, M2) and inorganic nutrient and an inoculum of A. borkumensis SK2 T and Thalassolituus oleivorans MIL-1 T (Mesocosm 3, M3), respectively. During the experimental period (20 days) bacterial abundance (DAPI count), culturable heterotrophic bacteria (CFU count), MPN, microbial metabolic activity [Biochemical Oxygen Demand and enzymatic activity (leucine aminopeptidase LAP, b-glucosidase BG, alkaline phosphatase AP)] and quali-, quantitative analysis of the composition of total extracted and resolved hydrocarbons and their derivates (TERHCs) were carried out. The microbiological and physiological analysis of marine microbial community found during the three different biostimulation and bioaugmentation assays performed in mesocosms show that the load of crude oil increases total microbial abundance, inhibits the activity of some enzymes such as LAP while stimulates both AP and BG activities. The biodegradation results show that bioaugmentation with A. borkumensis SK2 T alone is able to produce the highest percentage of degradation (95%) in comparison with the biostimulation treatment (80%) and bioaugmentation using an Alcanivorax-Thalassolituus bacterial consortium (70%). This result highlights the reduced biodegradation capability of the consortium used in this study, suggesting an unfavourable interaction between the two bacterial genera.

Research paper thumbnail of Antibacterial Activity of Some Plant Extracts Used in Folk Medicine

Journal of Herbal Pharmacotherapy, 2008

The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli isolates make many seriou... more The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli isolates make many serious infections, especially urinary tract infections. Objectives: The purpose of this study was to determine the antibacterial activities of some natural plant extracts against ESBL-producing E. coli isolates, which harbor the TEM gene in urine samples of the patients who have urinary tract infections. Materials and Methods: Evaluation has to be exactly determined for both methods of disk diffusion test and polymerase chain reaction (PCR), separately. We evaluated 120 strains of E. coli isolates from the urine culture of the patients in Boo-Ali Hospital (Zahedan, southeastern Iran) who were suffering from urinary tract infections. The ESBL-producing E. coli isolates were evaluated by disk diffusion test and PCR through TEM gene detection. The minimal inhibitory concentration (MIC) of commonly used antibiotics including ceftazidime, ceftriaxon, amikacin, gentamicin and ciprofloxacin along with the MIC of the alcoholic extract of different natural plants including Myrtus communis L (Myrtaceae), Amaranthus retraflexus (Amaranthaceae), Cyminum cuminum L (Apiaceae), Marrubium vulgare (Laminaceae) and Peganum. harmala (Zygrophyllaceae) against the ESBL-producing E. coli isolates, which harbor the TEM genes, were determined using the microdulition method. Results: Results of this study showed that in disk diffusion method, 80 samples of E. coli produced ESBLs. In PCR method, the TEM gene distribution in the isolated ESBL-producing organisms was 50 (41.6%). Amikacin was the most effective anti-bacterial agent and ciprofloxacin was the least effective against E. coli isolates. All the natural plant extracts mentioned above, especially P. harmala, were effective against the selected isolates of ESBL-producing E. coli. The most frequent ESBL rate producing E. coli isolates (32 out of 50) had MIC of 2.5 mg/mL in ethanol extract of P. harmala. Conclusions: The alcoholic extract of P. harmala was very effective against the selected ESBL-producing E. coli isolates harboring the TEM gene. Therefore, it could be suggested as an antibacterial agent in the future. More researches are necessary for detecting the mechanism of this plant's behavior and its pharmacological effects.

Research paper thumbnail of Isolation and characterization of biosurfactant-producing Alcanivorax strains: hydrocarbon accession strategies and alkane hydroxylase gene analysis

Research in Microbiology, 2009

Biosurfactants and biopolymers are key players for microbial enhanced oil recovery (MEOR) mechani... more Biosurfactants and biopolymers are key players for microbial enhanced oil recovery (MEOR) mechanisms. These biomolecules can be produced In-situ or Ex-situ and can be utilised for enhancing oil recovery. In this study, several aerobic spore forming bacteria were isolated from diverse habitats for ex-situ MEOR. The selected 16 isolates were identified by 16s rRNA sequencing and screened for better biosurfactant and biopolymer production using different production medium at shake flask level. One Bacillus subtilis strain W19, was found to be a promising biosurfactant producer and it reduced ST and IFT from 72 to 27mN/m and from 46 to 3.3mN/m respectively in less than 20 hours.

Research paper thumbnail of Paper: CLONING AND GENE EXPRESSION OF CYTOCHROME P450 GENE FROM ALCANIVORAX BORKUMENSIS BACTERIUM

Research paper thumbnail of Paper: DEGRADATION OF ALKANES IN CONTAMINATED SITES

Research paper thumbnail of Paper: ANTIMICROBIAL ACTIVITY OF TRACHYSPERMUM AMMI ESSENTIAL OIL AGAINST HUMAN BACTERIAL

Research paper thumbnail of SCREENING, IDENTIFICATION AND EVALUATION OF PROBIOTIC POTENTIAL OF ENTEROCOCCI IN TRADITIONAL DAIRY PRODUCTS OF SABZEVAR

Research paper thumbnail of Antibacterial Effect of Ethanol Extract of Camellia Sinensis L against Escherichia Coli

Research paper thumbnail of Isolation and characterization of phenol degrading bacteria from Persian Gulf

This study investigated the aerobic degradation of phenol by yeast strains isolated from an oil r... more This study investigated the aerobic degradation of phenol by yeast strains isolated from an oil refinery wastewater from the Northeast of Brazil. The samples displayed low fungal diversity, as only yeast colonies were detected on Sabouraud dextrose agar containing chloramphenicol 0.05% (w/v). Among the isolates, three yeast strains were selected to be evaluated for their potential for degrading high phenol concentrations. These species were identified through morphological and biochemical characteristics as Candida tropicalis, C. rugosa, and Pichia membranaefaciens. Although the strains were able to degrade the phenol concentration present in the wastewater, which was 7 mg l À1 , only C. tropicalis was capable of growing at high concentrations of phenol such as 500 mg l À1 and 1,000 mg l À1 in a mineral medium containing this pollutant as the only carbon source. C. rugosa and P. membranaefaciens were inhibited in the presence of 500 mg l À1 of phenol. However, a longer incubation time was needed for C. tropicalis strain to degrade 1,000 mg l À1 of phenol compared to the time required to degrade 500 mg l À1 . Moreover, the strain released a significant amount of polysaccharide biosurfactant in the medium probably to minimize the toxic effect of the high phenol concentration. When challenged with 1,500 and 2,000 mg l À1 of phenol, C. tropicalis was unable to grow at the tested conditions. The results indicate that this strain of C. tropicalis can be considered both a good phenol-degrader and biosurfactant-producer. Application of this strain might be useful in bioremediation activities or treatment of phenol-polluted wastewater.

Research paper thumbnail of Isolation and characterization of crude-oil-degrading bacteria from the Persian Gulf and the Caspian Sea

Marine Pollution Bulletin, 2012

Twenty-five crude-oil-degrading bacteria were isolated from oil-contaminated sites in the Persian... more Twenty-five crude-oil-degrading bacteria were isolated from oil-contaminated sites in the Persian Gulf and the Caspian Sea. Based on a high growth rate on crude oil and on hydrocarbon degradation ability, 11 strains were selected from the 25 isolated strains for further study. Determination of the nucleotide sequence of the 16S rRNA gene showed that these isolated strains belonged to genera Acinetobacter, Pseudomonas, Gordonia, Rhodococcus, Cobetia, Halomonas, Alcanivorax, Marinobacter and Microbacterium. Among the 11 isolates, strains BS ( Acinetobacter calcoaceticus, 98%) and PG-12 ( Alcanivorax dieselolei, 98%) were the most effective in degrading crude oil. Rate of crude-oil degradation of 82% (isolate BS) and 71% (isolate PG-12) were observed after 1 week of cultivation in mineral medium. These strains had high emulsification activity and biosurfactant production. GC-MS analysis showed that A. dieselolei PG-12 can degrade different alkanes in crude oil. Screening of the distribution of the alkane hydroxylase gene in 25 isolates in relation to the source of isolation indicated that the group (II) alkane hydroxylase is prevalent in the Caspian Sea, but in the Persian Gulf, the frequency of the group (III) alkane hydroxylase gene is greater than that of the group (II) alkane hydroxylase gene.

Research paper thumbnail of Isolation and characterization of alkane degrading bacteria from petroleum reservoir waste water in Iran (Kerman and Tehran provenances)

Marine Pollution Bulletin, 2013

and sharing with colleagues.

Research paper thumbnail of Bioremediation (bioaugmentation/biostimulation) trials of oil polluted seawater: A mesocosm simulation study

Marine Environmental Research, 2014

Bioaugmentation (amendment with selected bacterial strains) and/or biostimulation (nutrients addi... more Bioaugmentation (amendment with selected bacterial strains) and/or biostimulation (nutrients addition and/or air supply) are relatively new fields in environmental microbiology for preventing pollution and cleanup contamination. In this study, the efficiency of application of bioaugmentation/biostimulation treatments, for recovery of crude oil-polluted seawater, was evaluated. Three different series of experiments were performed in a "Mesocosm Facility" (10.000 L). Natural seawater was artificially polluted with crude oil (1000 ppm) and was amended with inorganic nutrients (Mesocosm 1, M1), inorganic nutrient and an inoculum of Alcanivorax borkumensis SK2 T (Mesocosm 2, M2) and inorganic nutrient and an inoculum of A. borkumensis SK2 T and Thalassolituus oleivorans MIL-1 T (Mesocosm 3, M3), respectively. During the experimental period (20 days) bacterial abundance (DAPI count), culturable heterotrophic bacteria (CFU count), MPN, microbial metabolic activity [Biochemical Oxygen Demand and enzymatic activity (leucine aminopeptidase LAP, b-glucosidase BG, alkaline phosphatase AP)] and quali-, quantitative analysis of the composition of total extracted and resolved hydrocarbons and their derivates (TERHCs) were carried out. The microbiological and physiological analysis of marine microbial community found during the three different biostimulation and bioaugmentation assays performed in mesocosms show that the load of crude oil increases total microbial abundance, inhibits the activity of some enzymes such as LAP while stimulates both AP and BG activities. The biodegradation results show that bioaugmentation with A. borkumensis SK2 T alone is able to produce the highest percentage of degradation (95%) in comparison with the biostimulation treatment (80%) and bioaugmentation using an Alcanivorax-Thalassolituus bacterial consortium (70%). This result highlights the reduced biodegradation capability of the consortium used in this study, suggesting an unfavourable interaction between the two bacterial genera.

Research paper thumbnail of Antibacterial Activity of Some Plant Extracts Used in Folk Medicine

Journal of Herbal Pharmacotherapy, 2008

The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli isolates make many seriou... more The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli isolates make many serious infections, especially urinary tract infections. Objectives: The purpose of this study was to determine the antibacterial activities of some natural plant extracts against ESBL-producing E. coli isolates, which harbor the TEM gene in urine samples of the patients who have urinary tract infections. Materials and Methods: Evaluation has to be exactly determined for both methods of disk diffusion test and polymerase chain reaction (PCR), separately. We evaluated 120 strains of E. coli isolates from the urine culture of the patients in Boo-Ali Hospital (Zahedan, southeastern Iran) who were suffering from urinary tract infections. The ESBL-producing E. coli isolates were evaluated by disk diffusion test and PCR through TEM gene detection. The minimal inhibitory concentration (MIC) of commonly used antibiotics including ceftazidime, ceftriaxon, amikacin, gentamicin and ciprofloxacin along with the MIC of the alcoholic extract of different natural plants including Myrtus communis L (Myrtaceae), Amaranthus retraflexus (Amaranthaceae), Cyminum cuminum L (Apiaceae), Marrubium vulgare (Laminaceae) and Peganum. harmala (Zygrophyllaceae) against the ESBL-producing E. coli isolates, which harbor the TEM genes, were determined using the microdulition method. Results: Results of this study showed that in disk diffusion method, 80 samples of E. coli produced ESBLs. In PCR method, the TEM gene distribution in the isolated ESBL-producing organisms was 50 (41.6%). Amikacin was the most effective anti-bacterial agent and ciprofloxacin was the least effective against E. coli isolates. All the natural plant extracts mentioned above, especially P. harmala, were effective against the selected isolates of ESBL-producing E. coli. The most frequent ESBL rate producing E. coli isolates (32 out of 50) had MIC of 2.5 mg/mL in ethanol extract of P. harmala. Conclusions: The alcoholic extract of P. harmala was very effective against the selected ESBL-producing E. coli isolates harboring the TEM gene. Therefore, it could be suggested as an antibacterial agent in the future. More researches are necessary for detecting the mechanism of this plant's behavior and its pharmacological effects.

Research paper thumbnail of Isolation and characterization of biosurfactant-producing Alcanivorax strains: hydrocarbon accession strategies and alkane hydroxylase gene analysis

Research in Microbiology, 2009

Biosurfactants and biopolymers are key players for microbial enhanced oil recovery (MEOR) mechani... more Biosurfactants and biopolymers are key players for microbial enhanced oil recovery (MEOR) mechanisms. These biomolecules can be produced In-situ or Ex-situ and can be utilised for enhancing oil recovery. In this study, several aerobic spore forming bacteria were isolated from diverse habitats for ex-situ MEOR. The selected 16 isolates were identified by 16s rRNA sequencing and screened for better biosurfactant and biopolymer production using different production medium at shake flask level. One Bacillus subtilis strain W19, was found to be a promising biosurfactant producer and it reduced ST and IFT from 72 to 27mN/m and from 46 to 3.3mN/m respectively in less than 20 hours.