Department of Biochemistry, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, Jagiellońska 28, 40-032 Katowice, Poland.
J Environ Manage. 2019 Jun 1;239:1-7. doi: 10.1016/j.jenvman.2019.03.034. Epub 2019 Mar 13.
Bacillus thuringiensis B1 (2015b) is a bacterial strain that is able to degrade naproxen. However, the potential effect of water co-contaminations on the degradation process and its pathway have not yet been evaluated. The results of our study show that in the presence of aromatic compounds, the B1 (2015b) strain utilised naproxen with an efficiency that was similar to what it was with no aromatic co-contaminations. In the presence of methanol, biodegradation of naproxen was inhibited, while the addition of ethanol increased the decomposition of naproxen. Among the metal ions that were tested, only cobalt (II) and cadmium (II) negatively affected the degradation of the drug. An analysis of the intermediates and enzymes that are engaged in degrading naproxen revealed that the key metabolites are O-desmethylnaproxen, which is the product of tetrahydrofolate-dependent O-demethylase activity, and salicylic acid. Salicylic acid can then be hydroxylated to catechol or gentisic acid or can be cleaved to 2-oxo-3,5-heptadienedioic acid. The high activity level of catechol 1,2-dioxygenase indicated that the main degradative pathway of naproxen in the B1 (2015b) strain is via catechol cleavage.
苏云金芽孢杆菌 B1（2015b）是一种能够降解萘普生的细菌菌株。然而，水共存污染物对降解过程及其途径的潜在影响尚未得到评估。我们的研究结果表明，在存在芳香族化合物的情况下，B1（2015b）菌株利用萘普生的效率与没有芳香族共存污染物时相似。在甲醇存在的情况下，萘普生的生物降解受到抑制，而添加乙醇则增加了萘普生的分解。在所测试的金属离子中，只有钴（II）和镉（II）对药物的降解产生负面影响。对参与降解萘普生的中间产物和酶的分析表明，关键代谢物是 O-去甲基萘普生，它是四氢叶酸依赖性 O-去甲基酶活性的产物，以及水杨酸。水杨酸然后可以被羟化为儿茶酚或龙胆酸，或者可以被裂解为 2-氧代-3,5-庚二烯二酸。儿茶酚 1,2-双加氧酶的高活性水平表明，B1（2015b）菌株中萘普生的主要降解途径是通过儿茶酚裂解。
