Characterization of Novel 4-n-Butylphenol- Degrading Pseudomonas Veronii Strains Isolated from Rhizosphere of Giant Duckweed, Spirodela polyrrhiza
Characterization of Novel 4-n-Butylphenol- Degrading Pseudomonas Veronii Strains Isolated from Rhizosphere of Giant Duckweed, Spirodela polyrrhiza
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DOI：
10.2521/jswtb.45.83
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
H. Hai;D. Inoue;Naonori Momotani;N. Yu;T. Toyama;K. Sei;M. Ike
中科院分区：
文献类型：
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作者：
H. Hai;D. Inoue;Naonori Momotani;N. Yu;T. Toyama;K. Sei;M. Ike
从水萍（Spirode/a po/yrrhiza）根际分离到一株能利用4-正丁基苯酚（4-n-BP）作为唯一碳源的细菌。这些细菌被鉴定为Veronii假单胞菌。该菌株能完全降解4-n-BP，最适温度为25 ℃，最适pH为6.0，最适NaCl浓度为0.1%，最适pH为5-8，最适温度为10-30 °C，最适NaCl浓度为1.5%。菌株nBPS对4-n-BP的降解符合米氏动力学，最大降解速率为0.258mmolmg·cell-1h，但在~ 0.075mM时，由于高底物浓度的抑制作用，4-n-BP的降解速率有所下降。根据GC-MS分析的代谢产物，提出了nBPS降解4-n-BP的途径：4-n-BP首先被羟基化为4-正丁基邻苯二酚，然后4-正丁基邻苯二酚通过Meta邻苯二酚裂解途径被代谢。菌株nBPS的4-n-BP降解酶对短链和中链（C2-CS）的4-n-AP非常有效，对长链（C6-C9）的4-n-AP也有很好的降解效果，但降解率随烷基链长度的增加而降低。
Novel bacteria capable of utilizing 4-n-butylphenol (4-n-BP) as the sole carbon source were isolated from rhizosphere of giant duckweed, Spirode/a po/yrrhiza. These bacteria were identified as Pseudomonas veronii. One of the isolates, P. veronii designated strain nBPS, could completely degrade 4-n-BP up to 1.0 mM. The strain was capable of growing on 4-n-BP at temperature of 10-30 °c, pH of 5-8 and NaCI concentration of 1.S % or less, and the optimal temperature, pH and NaCI concentration were 2S °c, 6.0 and 0.1 %, respectively. Specific 4-n-BP-degrading activity of strain nBPS followed the Michaelis Menten kinetics, with the maximal degradation rate of 0.2S8 mmollmg-celllh although the activity declined at ~0.07S mM probably due to inhibitory effect of high substrate concentration. Based on the metabolites identified by GC-MS, the pathway of 4-n-BP degradation by strain nBPS was proposed: 4-n-BP is initially hydroxylated to 4-n-butylcatechol, and subsequently 4-n-butylcatechol is metabolized via the meta cleavage pathway. 4-n-BP-degrading enzyme of strain nBPS was very effective to 4-n-alkylphenols (4-n-APs) with short and medium alkyl chain (C2-CS) and effective to 4-n-APs with long alkyl chains (C6-C9) although the degradation ratio declined with increase of length of alkyl chain.