Iwaki Hiroaki, Hasegawa Yoshie
Department of Biotechnology, Faculty of Engineering, Kansai University, Japan.
Biosci Biotechnol Biochem. 2007 Jan;71(1):145-51. doi: 10.1271/bbb.60419. Epub 2007 Jan 7.
Bacterial strain KU-15, identified as a Burkholderia terrae by 16S rRNA gene sequence analysis, was one of 11 new isolates that grew on 2-nitrobenzoate as sole source of carbon and nitrogen. Strain KU-15 was also found to grow on anthranilate, 4-nitrobenzoate, and 4-aminobenzoate. Whole cells of strain KU-15 were found to accumulate ammonia in the medium, indicating that the degradation of 2-nitrobenzoate proceeds through a reductive route. Metabolite analyses by high-performance liquid chromatography indicated that 3-hydroxyanthranilate, anthranilate, and catechol are intermediates of 2-nitrobenzoate metabolism in strain KU-15. Enzyme studies suggested that 2-nitrobenzoate degradation occurs via the formation of 2-hydroxylaminobenzoate and that the pathway branches at this point to form two different aromatic intermediates: anthranilate and 3-hydroxyanthranilate. PCR amplifications and DNA sequencing revealed DNA fragments encoding a polypeptide homologous to 2-amino-3-carboxymuconate 6-semialdehyde decarboxylase and anthranilate 1,2-dioxygenase.
通过16S rRNA基因序列分析鉴定为土生伯克霍尔德菌的细菌菌株KU-15，是在2-硝基苯甲酸作为唯一碳源和氮源的情况下生长的11株新分离菌株之一。还发现菌株KU-15能在邻氨基苯甲酸、4-硝基苯甲酸和4-氨基苯甲酸上生长。发现菌株KU-15的全细胞在培养基中积累氨，这表明2-硝基苯甲酸的降解是通过还原途径进行的。高效液相色谱法进行的代谢物分析表明，3-羟基邻氨基苯甲酸、邻氨基苯甲酸和儿茶酚是菌株KU-15中2-硝基苯甲酸代谢的中间产物。酶学研究表明，2-硝基苯甲酸的降解是通过形成2-羟基氨基苯甲酸发生的，并且该途径在这一点上分支形成两种不同的芳香族中间体：邻氨基苯甲酸和3-羟基邻氨基苯甲酸。PCR扩增和DNA测序揭示了编码与2-氨基-3-羧基粘康酸6-半醛脱羧酶和邻氨基苯甲酸1,2-双加氧酶同源的多肽的DNA片段。
