Department of Microbiology, Bose Institute, P-1/12 C.I.T. Scheme VII M, Kolkata, India.
Microbiology (Reading). 2014 May;160(Pt 5):892-902. doi: 10.1099/mic.0.077495-0. Epub 2014 Feb 19.
Burkholderia sp. strain BC1, a soil bacterium, isolated from a naphthalene balls manufacturing waste disposal site, is capable of utilizing 2-hydroxy-1-naphthoic acid (2H1NA) and naphthalene individually as the sole source of carbon and energy. To deduce the pathway for degradation of 2H1NA, metabolites isolated from resting cell culture were identified by a combination of chromatographic and spectrometric analyses. Characterization of metabolic intermediates, oxygen uptake studies and enzyme activities revealed that strain BC1 degrades 2H1NA via 2-naphthol, 1,2,6-trihydroxy-1,2-dihydronaphthalene and gentisic acid. In addition, naphthalene was found to be degraded via 1,2-dihydroxy-1,2-dihydronaphthalene, salicylic acid and gentisic acid, with the putative involvement of the classical nag pathway. Unlike most other Gram-negative bacteria, metabolism of salicylic acid in strain BC1 involves a dual pathway, via gentisic acid and catechol, with the latter being metabolized by catechol 1,2-dioxygenase. Involvement of a non-oxidative decarboxylase in the enzymic transformation of 2H1NA to 2-naphthol indicates an alternative catabolic pathway for the bacterial degradation of hydroxynaphthoic acid. Furthermore, the biochemical observations on the metabolism of structurally similar compounds, naphthalene and 2-naphthol, by similar but different sets of enzymes in strain BC1 were validated by real-time PCR analyses.
伯克霍尔德氏菌（Burkholderia sp.）菌株 BC1 是一种从萘球制造废物处理场分离出来的土壤细菌，能够单独将 2-羟基-1-萘甲酸（2H1NA）和萘用作碳源和能源。为了推断降解 2H1NA 的途径，通过色谱和光谱分析相结合，鉴定了来自静止细胞培养物的代谢产物。代谢中间产物的特性、氧摄取研究和酶活性表明，BC1 菌株通过 2-萘酚、1,2,6-三羟基-1,2-二氢萘和龙胆酸降解 2H1NA。此外，发现萘通过 1,2-二羟基-1,2-二氢萘、水杨酸和龙胆酸降解，推测涉及经典的 nag 途径。与大多数其他革兰氏阴性菌不同，BC1 菌株中水杨酸的代谢涉及双途径，通过龙胆酸和儿茶酚，后者由儿茶酚 1,2-双加氧酶代谢。在 2H1NA 向 2-萘酚的酶转化中涉及非氧化脱羧酶，表明细菌降解羟基萘酸的替代代谢途径。此外，通过实时 PCR 分析验证了在 BC1 菌株中类似但不同的酶对结构类似化合物萘和 2-萘酚的代谢的生化观察。
