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Viggor Signe Heinaru Eeva Loponen Jyrki Merimaa Merike Tenno Toomas Heinara Ain 《Environmental science and pollution research international》2002,9(1):19-26
The biodegradation of 3,4, 2,4, 2,3, 2,6 and 3,5-di-methylphenol in combination with phenol andp-cresol by axenic and mixed cultures of bacteria was investigated. The strains, which degrade phenol andp-cresol through different catabolic pathways, were isolated from river water continuously polluted with phenolic compounds of leachate of oil shale semicoke ash heaps. The proper research of degradation of 2,4 and 3,4-di-methylphenol in multinutrient environments was performed. The degradation of phenolic compounds from mixtures indicated a flux of substrates into different catabolic pathways. Catechol 2,3-dioxygenase activity was induced by dimethylphenols inPseudomonas mendocina PC1, wheremeta cleavage pathway was functional during the degradation ofp-cresol. In the case of strains PC18 and PC24 ofP. fluorescens, the degradation ofp-cresol occurred via the protocatechuateortho pathway and the key enzyme of this pathway,p-cresol methylhydroxylase, was also induced by dimethylphenols. 2,4 and 3,4-dimethylphenols were converted into the dead-end products 4-hydroxy-3-methylbenzoic acid and 4-hydroxy-2-methylbenzoic acid. In the degradation of 3,4-dimethylphenol, the transient accumulation of 4-hydroxy-2-methylbenzaldehyde repressed the consumption of phenol from substrate mixtures. A mixed culture of strains with different catabolic types made it possible to overcome the incompatibilities at degradation of studied substrate mixtures. 相似文献
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von Bobrutzki K Ammon C Berg W Einert P Fiedler M Müller HJ Scherer D Strohbach B 《Environmental monitoring and assessment》2012,184(6):3775-3787
Agricultural NH3 emissions affect air quality and influence the nitrogen cycle. In the subject study, NH3 emissions from a broiler farm and the resulting atmospheric concentrations in the immediate vicinity during three growing
cycles have been quantified. Additionally, vegetation along a transect in an adjacent woodland was analysed. The emissions
were as high as 10 kg NH3 h−1 and the atmospheric concentrations ranged between 33 and 124 μg NH3 m−3 per week in the immediate vicinity. Measurements of the atmospheric concentrations over 7 weeks showed a substantial decline
of mean concentrations (based on a 3-week average) from ∼13 to <3 μg NH3 m−3, at 45- and 415-m distance from the farm. Vegetation surveys showed that nitrophilous species flourished when they grew closest
to the farm (their occurrence sank proportionately with distance). A clearly visible damage of pine trees was observed within
200 m of the farm; this illustrated the significant impact of NH3 emissions from agricultural sources on the sensitive ecosystem. 相似文献
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