Gisi D, Stucki G, Hanselmann K W
University of Zürich, Institute of Plant Biology/Microbiology, Switzerland.
Appl Microbiol Biotechnol. 1997 Oct;48(4):441-8. doi: 10.1007/s002530051077.
A mixed culture of microorganisms able to utilize 4,6-dinitro-ortho-cresol (DNOC) as the sole source of carbon, nitrogen and energy was isolated from soil contaminated with pesticides and from activated sludge. DNOC was decomposed aerobically in batch cultures as well as in fixed-bed column reactors. Between 65% and 84% of the substrate nitrogen was released as nitrate into the medium, and 61% of the carbon from uniformly 14C-labelled DNOC was recovered as 14CO2. The mixed microbial culture also decomposed 4-nitrophenol and 2,4-dinitrophenol but not 2,3-dinitrophenol, 2,6-dinitrophenol, 2,4-dinitrotoluene, 2,4-dinitrobenzoic acid or 2-sec-butyl-4,6-dinitrophenol (Dinoseb). Maximal degradation rates for DNOC by the bacterial biofilm immobilized on glass beads in fixed-bed column reactors were 30 mmol day-1 (1 reactor volume)-1, leaving an effluent concentration of less than 5 micrograms l-1 DNOC in the outflowing medium. The apparent Ks value of the immobilized mixed culture for DNOC was 17 microM. Degradation was inhibited at DNOC concentrations above 30 microM and it ceased at 340 microM, possibly because of the uncoupling action of the nitroaromatic compound on the cellular energy-transducing mechanism.
从受农药污染的土壤和活性污泥中分离出一种能够利用4,6-二硝基邻甲酚（DNOC）作为唯一碳、氮和能量来源的混合微生物培养物。DNOC在分批培养以及固定床柱式反应器中进行好氧分解。65%至84%的底物氮以硝酸盐形式释放到培养基中，来自均匀标记14C的DNOC的61%的碳以14CO2形式回收。该混合微生物培养物还能分解4-硝基苯酚和2,4-二硝基苯酚，但不能分解2,3-二硝基苯酚、2,6-二硝基苯酚、2,4-二硝基甲苯、2,4-二硝基苯甲酸或2-仲丁基-4,6-二硝基苯酚（地乐酚）。固定床柱式反应器中固定在玻璃珠上的细菌生物膜对DNOC的最大降解速率为30 mmol·天-1·（1个反应器体积）-1，流出培养基中DNOC的流出浓度低于5微克·升-1。固定化混合培养物对DNOC的表观Ks值为17微摩尔。当DNOC浓度高于30微摩尔时降解受到抑制，在340微摩尔时降解停止，这可能是由于硝基芳烃化合物对细胞能量转换机制的解偶联作用。
