List of Articles oxyanion

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  1 - The Comparative Study of telluride removal by a moderately halophilous bacterium, Halomonas elongate, a halotolerant bacterium, Enterococcus faecalis and a non-halophilous bacterium, Pseudomonas aeruginosa
  Zeynab Sadat Motesharrei Mohammad Ali Amoozegar
  Halophilous, halotolerant and non-halophilous microorganisms have important roles in bioremediation and transformation of toxic metal compounds in polluted environments. Identification of toxic metal-tolerant strains and their removal patterns are the first steps of app More

  Halophilous, halotolerant and non-halophilous microorganisms have important roles in bioremediation and transformation of toxic metal compounds in polluted environments. Identification of toxic metal-tolerant strains and their removal patterns are the first steps of applying them in the bioremediation processes. In the current study, telluride removal in three moderately halophilous, halotolerant and non-halophilous bacteria, Halomonas elongate DSM 2581, Enterococcus faecalis PTCC1237 and Pseudomonas aeruginosa PTCC1074, respectively, and the effects of selenooxyanions and arsenate on this removal, were determined by means of a colorimetric method using di-ethyl thio-carbamate. The strains H. elongate, E. faecalis and Ps. aeruginosa showed the maximum MIC to telluride as 0.25, 8 and 0.25 mM, respectively. In halophilous microorganism, H. elongata, selenooxyanions had a positive effect on increasing the telluride resistance, since K-telluride plus 25 mM  Na-Selenite or Na-selenate were added together into the medium, tolerance to telluride was increased from 0.25 mM to 18 mM and from 0.25 mM to 3 mM, respectively , telluride tolerance in halotolerant strain ,E. faecalis, in the presence of 25 mM Se (IV) or 5 mM Se (VI) or 0.1 mM As (V) was increased and reached to 80 mM , 16 mM and 16 mM , respectively,but in Non-halophilous bacterium, Ps. aeruginosa adding 25 mM Se (IV) or 5 mM Se (VI) or 5 mM As (V) did not cause increasing of MIC of telluride. The ability of halophilous strain to telluride removal was increased in comparison of control condition (medium containing of just telluride) by 48/21% and 25.74% , when 0.1 mM Te(IV) plus 50 mM Se (IV) or 1 mM Se (VI) was used respectively. 0.2 mM Te (IV) plus 1 mM Se (IV) or 1 mM Se (VI) or 0.1 mM As (V) in E. faecalis can give rise 2.2% , 7.33%  and 75% increase in Telluride removal, as well. The most positive effect of Selenite and Selenate in Telluride removal was observed in              H. elongata and the lowest of it was observed in E. faecalis. A unique characteristic of E. faecalis in removing of Tellurite by 75% in the presence of Arsenate was the thing which observed only in E. faecalis but not in two other bacteria studied here. In the case of P. aeruginosa, 8 mM Se (IV) or 1 mM Se (VI) plus 0.1 mM Te (IV) can also cause higher increase in telluride removal by 34.35% and 11.82%, respectively. X-ray fluorescence (XRF) studies and scanning transmission electron microscopy examination using an EDS analysis system, demonstrated that the black and red deposits formed in bacterial cells, was metallic tellurium and selenium Manuscript profile
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  2 - 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 Soleimani
  The 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 More

  The 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