Chen Kai, Jian Shanshan, Huang Linglong, Ruan Zhepu, Li Shunpeng, Jiang Jiandong
Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Biotechnol Lett. 2015 Dec;37(12):2395-401. doi: 10.1007/s10529-015-1932-z. Epub 2015 Aug 12.
To confirm the reductive dehalogenation ability of the aerobic strain of Delftia sp. EOB-17, finding more evidences to support the hypothesis that reductive dehalogenation may occur extensively in aerobic bacteria.
Delftia sp. EOB-17, isolated from terrestrial soil contaminated with halogenated aromatic compounds, completely degraded 0.2 mM DBHB in 28 h and released two equivalents of bromides under aerobic conditions in the presence of sodium succinate. LC-MS analysis revealed that DBHB was transformed to 4-hydroxybenzoate via 3-bromo-4-hydroxybenzoate by successive reductive dehalogenation. Highly conserved DBHB-degrading genes, including reductive dehalogenase gene (bhbA3) and the extra-cytoplasmic binding receptor gene (bhbB3), were also found in strain EOB-17 by genome sequencing. The optimal temperature and pH for DBHB reductive dehalogenation activity are 30 °C and 8, respectively, and 0.1 mM Cd(2+), Cu(2+), Hg(2+) and Zn(2+) strongly inhibited dehalogenation activity.
The aerobic strain of Delftia sp. EOB-17 was confirmed to reductively dehalogenate DBHB under aerobic conditions, providing another evidence to support the hypothesis that reductive dehalogenation occurs extensively in aerobic bacteria.
确认代尔夫特菌属好氧菌株EOB - 17的还原脱卤能力，寻找更多证据支持还原脱卤可能在好氧细菌中广泛发生的假说。
从受卤代芳香化合物污染的陆地土壤中分离出的代尔夫特菌属EOB - 17，在有氧条件下，于28小时内完全降解了0.2 mM的DBHB，并在琥珀酸钠存在下释放出两当量的溴化物。液相色谱 - 质谱分析表明，DBHB通过连续的还原脱卤作用先转化为3 - 溴 - 4 - 羟基苯甲酸酯，再转化为4 - 羟基苯甲酸酯。通过基因组测序在菌株EOB - 17中还发现了高度保守的DBHB降解基因，包括还原脱卤酶基因（bhbA3）和胞外结合受体基因（bhbB3）。DBHB还原脱卤活性的最适温度和pH分别为30°C和8，0.1 mM的Cd(2+)、Cu(2+)、Hg(2+)和Zn(2+)强烈抑制脱卤活性。
代尔夫特菌属好氧菌株EOB - 17被证实可在有氧条件下对DBHB进行还原脱卤，为支持还原脱卤在好氧细菌中广泛发生的假说提供了又一证据。
