Plasmid-encoded degradation of p-nitrophenol and 4-nitrocatechol by Arthrobacter protophormiae
Plasmid-encoded degradation of p-nitrophenol and 4-nitrocatechol by Arthrobacter protophormiae
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DOI：
10.1006/bbrc.2000.2500
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发表时间：
2000-04-21
影响因子：
3.1
通讯作者：
Jain, RK
中科院分区：
文献类型：
--
作者：
Chauhan, A;Chakraborti, AK;Jain, RK
节杆菌RKJ 100菌株能够利用对硝基苯酚（PNP）以及4-硝基邻苯二酚（NC）作为唯一的碳源、氮源和能量源。该微生物对PNP和NC的降解通过氧化途径发生，因为当该菌株在PNP或NC作为唯一的碳源和能量源上生长时观察到亚硝酸盐分子的化学计量。通过TLC、GC、H-1 NMR、GC-MS、UV光谱和HPLC分析，在酶测定和中间体化学表征的基础上阐明了PNP和NC的降解途径。我们的研究清楚地表明，PNP的降解过程中，生成对苯醌（BQ）和对苯二酚（HQ），并通过β-酮己二酸途径进一步降解。NC的降解包括初始氧化生成1，2，4-苯三醇（BT）和2-羟基-1，4-苯醌;然后将后一中间体还原脱羟基，形成BQ和HQ，并通过β-酮己二酸进一步裂解成TCA中间体。因此，很可能同一组基因编码PNP和NC降解中HQ的进一步代谢。一个约65 kb的质粒被发现是负责窝藏PNP和NC降解基因在这个菌株。这是基于以下事实：PNP-NC-衍生物不含质粒，同时失去了以这些硝基芳族化合物为代价生长的能力. (C)北京大学出版社.
Arthrobacter protophormiae strain RKJ100 is capable of utilizing p-nitrophenol (PNP) as well as 4-nitrocatechol (NC) as the sole source of carbon, nitrogen and energy, The degradation of PNP and NC by this microorganism takes place through an oxidative route, as stoichiometry of nitrite molecules was observed when the strain was grown on PNP or NC as sole carbon and energy sources. The degradative pathways of PNP and NC were elucidated on the basis of enzyme assays and chemical characterization of the intermediates by TLC, GC, H-1 NMR, GC-MS, UV spectroscopy, and HPLC analyses. Our studies clearly indicate that the degradation of PNP proceeds with the formation of p-benzoquinone (BQ) and hydroquinone (HQ) and is further degraded via the beta-ketoadipate pathway, Degradation of NC involved initial oxidation to generate 1,2,4-benzenetriol (BT) and 2-hydroxy-1,4-benzoquinone; the latter intermediate is then reductively dehydroxylated, forming BQ and HQ, and is further cleaved via beta-ketoadipate to TCA intermediates. It is Likely, therefore, that the same set of genes encode the further metabolism of HQ in PNP and NC degradation. A plasmid of approximately 65 kb was found to be responsible for harboring genes for PNP and NC degradation in this strain. This was based on the fact that PNP- NC- derivatives were devoid of the plasmid and had simultaneously lost their capability to grow at the expense of these nitroaromatic compounds. (C) 2000 Academic Press.