Browsing by Subject "bacterium"

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    Effective biodegradation of 2,4,6-trinitrotoluene using a novel bacterial strain isolated from TNT-contaminated soil
    (2013) Gumuscu, B.; Tekinay, T.
    In this environmental-sample based study, rapid microbial-mediated degradation of 2,4,6-trinitrotoluene (TNT) contaminated soils is demonstrated by a novel strain, Achromobacter spanius STE 11. Complete removal of 100mgL-1 TNT is achieved within only 20h under aerobic conditions by the isolate. In thisbio-conversion process, TNT is transformed to 2,4-dinitrotoluene (7mgL-1), 2,6-dinitrotoluene (3mgL-1), 4-aminodinitrotoluene (49mgL-1) and 2-aminodinitrotoluene (16mgL-1) as the key metabolites. A. spanius STE 11 has the ability to denitrate TNT in aerobic conditions as suggested by the dinitrotoluene and NO3 productions during the growth period. Elemental analysis results indicate that 24.77mgL-1 nitrogen from TNT was accumulated in the cell biomass, showing that STE 11 can use TNT as its sole nitrogen source. TNT degradation was observed between pH 4.0-8.0 and 4-43°C; however, the most efficient degradation was at pH 6.0-7.0 and 30°C. © 2013 Elsevier Ltd.
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    Heterotrophic ammonium removal by a novel hatchery isolate Acinetobacter calcoaceticus STB1
    (2012) Sarioglu O.F.; Suluyayla, R.; Tekinay, T.
    A novel bacterial strain, STB1, was isolated from a commercial sea bass hatchery and found to display high heterotrophic ammonium removal characteristics at different concentrations of ammonium (NH4+-N). The species identity of STB1 was determined via 16S rRNA gene sequence analysis to be Acinetobacter calcoaceticus. We evaluated ammonium removal characteristics of STB1 at varying ammonium concentrations, and observed that STB1 can almost completely remove ammonium at low (50 mg l -1), and medium (100 mg l -1) concentrations within 72 h, while 45% ammonium removal was observed at a higher concentration (210 mg l -1) during the same period. Trace amount of the metabolized ammonium was converted to nitrite or nitrate and 22.16% of total nitrogen was incorporated into cell biomass, while 4.34% of total nitrogen was initially incorporated into cell biomass and subsequently released to the supernatant fraction in the 100 mg l -1 sample. Most of the remaining conversion products are expected to be gaseous denitrification products. Toxicological studies with Artemia salina (brine shrimp) nauplii revealed that STB1 strain is non-toxic to Artemia larvae, which suggests that STB1 can be safely and efficiently utilized in water quality enrichment in aquatic ecosystems. © 2012 Elsevier Ltd.