Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites.

Degradation of 2,4,6-trinitrotoluene (TNT), a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitro experiments . Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L (-1) TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC). In cultures supplemented with 50 and 75 mgL (-1) TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT) and 4-aminodinitrotoluene (4-ADNT), were elucidated by thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS). These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites

Degradation of 2,4,6-trinitrotoluene (TNT), a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitro experiments. Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L−1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC). In cultures supplemented with 50 and 75 mgL−1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT) and 4-aminodinitrotoluene (4-ADNT), were elucidated by thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS). These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

Preliminary examination of herbal extracts on the inhibition of Helicobacter pylori.

BACKGROUND: This work aims at describing the traditional uses, to determine the antimicrobial potential of two different extracts hexane, acetone of the leaves of Citrus unshiu, Citrus sinensis, Citrus limon, Laurus nobilis, Citrus paradisi on clinical strain of H. pylori in a bid to identify potential sources of cheap starting materials for the synthesis of new drugs. H. pylori strain was a culture collection of Hacettepe University, Turkey. METHODS: The activity was quantitatively assessed on the basis of the inhibition zone, and their activity index was also calculated along with the MIC method. RESULTS: All the plants demonstrated antimicrobial activity against H. pylori with zone of inhibition diameters ranging from 0 - 30 mm and minimum inhibitory concentration (MIC) values ranging from 1:512-1:4096 dilutions. CONCLUSION: The results may serve as scientific validation of the ethnomedicinal uses of the Citrus unshiu, Citrus sinensis, Citrus limon, Laurus nobilis, and Citrus paradisi in the treatment of H. pylori-related infections. However, further investigations would be necessary to determine their toxicological properties, in-vivo potencies and mechanism of action against H. pylori.

Aerobic biodegradation of 2,4,6-trinitrotoluene (TNT) by Bacillus cereus isolated from contaminated soil.

In this study, biological degradation of 2,4,6-trinitrotoluene (TNT) which is very highly toxic environmentally and an explosive in nitroaromatic character was researched in minimal medium by Bacillus cereus isolated from North Atlantic Treaty Organization (NATO) TNT-contaminated soils. In contrast to most previous studies, the capability of this bacteria to transform in liquid medium containing TNT was investigated. During degradation, treatment of TNT was followed by high-performance liquid chromatography (HPLC) and achievement of degradation was calculated as percentage. At an initial concentration of 50 and 75 mg L(-1), TNT was degraded respectively 68 % and 77 % in 96 h. It transformed into 2,4-dinitrotoluene and 4-aminodinitrotoluene derivates, which could be detected as intermediate metabolites by using thin-layer chromatography and gas chromatography-mass spectrometry analyses. Release of nitrite and nitrate ions were searched by spectrophotometric analyses. Depending upon Meisenheimer complex, while nitrite production was observed, nitrate was detected in none of the cultures. Results of our study propose which environmental pollutant can be removed by using microorganisms that are indigenous to the contaminated site.

Acute renal failure due to Brucella melitensis.

We present the case of a 42-year-old male patient who applied to the emergency department of our hospital with clinical nephritis, orchitis, acute renal failure without endocarditis, and a low-grade fever. Brucella agglutinin titers were 1:160, Rose Bengal test was positive and Brucella melitensis was isolated from urine and blood cultures.. A combination of oral rifampin (600 mg/day) and doxycycline (200 mg/day) was administered along with supportive treatment leading to resolution of his clinical status by eight weeks. This was a rare complication of severe renal involvement due to brucellosis which resolved with antibiotic treatment.