Meng M, Sun W Q, Geelhaar L A, Kumar G, Patel A R, Payne G F, Speedie M K, Stacy J R
Department of Pharmaceutical Sciences, University of Maryland at Baltimore 21201-1180, USA.
Appl Environ Microbiol. 1995 Jul;61(7):2548-53. doi: 10.1128/aem.61.7.2548-2553.1995.
A number of microorganisms were selected from soil and sediment samples which were known to have been previously exposed to nitrate ester contaminants. The two most effective bacteria for transforming glycerol trinitrate (GTN) were identified as Bacillus thuringiensis/cereus and Enterobacter agglomerans. For both isolates, denitration activities were expressed constitutively and GTN was not required for induction. Dialysis of cell extracts from both isolates did not affect denitration, which indicates that dissociable and depletable cofactors are not required for denitration. With thin-layer chromatography and high-performance liquid chromatography, the denitration pathway for both isolates was shown to be a sequential denitration of GTN to glycerol dinitrate isomers, glycerol mononitrate isomers, and ultimately to glycerol. GTN was observed to be completely converted to glycerol during a long-term incubation of cell extracts.
从已知先前已接触过硝酸酯污染物的土壤和沉积物样本中挑选出了多种微生物。经鉴定,转化甘油三硝酸酯(GTN)最有效的两种细菌是苏云金芽孢杆菌/蜡样芽孢杆菌和成团肠杆菌。对于这两种分离菌株,脱氮活性是组成型表达的,诱导过程不需要GTN。对这两种分离菌株的细胞提取物进行透析并不影响脱氮,这表明脱氮不需要可解离和可耗尽的辅因子。通过薄层色谱法和高效液相色谱法,这两种分离菌株的脱氮途径均显示为GTN依次脱氮生成二硝酸甘油酯异构体、单硝酸甘油酯异构体,最终生成甘油。在细胞提取物的长期孵育过程中,观察到GTN完全转化为甘油。