Characterization of a pH-Tolerant Strain Cobetia sp. SASS1 and Its Phenol Degradation Performance Under Salinity Condition
Characterization of a pH-Tolerant Strain Cobetia sp. SASS1 and Its Phenol Degradation Performance Under Salinity Condition
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pH 耐受菌株 Cobetia sp 的表征。
DOI：
10.3389/fmicb.2019.02034
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发表时间：
2019-09-04
影响因子：
5.2
通讯作者：
Su, Xiaomei
中科院分区：
文献类型：
--
作者：
Mei, Rongwu;Zhou, Meng;Su, Xiaomei
复杂含盐含酚废水的生物处理仍然是一个巨大的挑战，由于在压力条件下的细菌种群的低活性。酸性矿井水作为一种典型的极端环境，形成了独特的酸性矿井水微生物群落。在AMD环境中存活的微生物已经进化出对低pH、高盐度和有毒重金属的各种抗性机制。这项工作的主要目标是确定从AMD分离的菌株是否可以在压力条件下降解苯酚，如低pH值，高盐度和重金属。结果表明，分离自AMD的Cobetia sp. SASS 1菌株与5个亲缘关系最近的种相比，具有不同的生理特性。SASS 1在较宽的pH（3.0-9.0）和NaCl浓度（0-40 g/L）范围内，以及Cu ~（2+）和Mn ~（2+）的存在下都能有效降解苯酚。在10 g/L NaCl溶液中，SASS 1可在80 h内完全降解1500 mg/L苯酚。同时实现了苯酚的矿化，在36 h内，900 mg/L的苯酚被完全降解，同时COD从2239 mg/L降至181.6 mg/L。通过对降解产物的鉴定和酶活性分析，提出苯酚降解的邻位裂解途径和苯甲酸途径。这些结果表明，SASS 1是一个有效的苯酚降解菌在盐度和酸性条件下，可以被认为是在压力条件下的工业酚废水的生物修复的关键种群。
Biological treatment of complex saline phenolic wastewater remains a great challenge due to the low activity of bacterial populations under stressful conditions. Acid mine drainage (AMD) as a typically extreme environment, shaped unique AMD microbial communities. Microorganisms survived in the AMD environment have evolved various mechanisms of resistance to low pH, high salinity and toxic heavy metals. The primary goal of this work was to determine whether a strain isolated from an AMD could degrade phenol under stressful conditions such as low pH, high salinity and heavy metals. The results suggested that the strain Cobetia sp. SASS1 isolated from AMD presented different physiological characteristics in comparison with five most closely related species. SASS1 can efficiently degrade phenol at wide ranges of pH (3.0–9.0) and NaCl concentration (0–40 g/L), as well as the existence of Cu2+ and Mn2+. Specifically, the SASS1 could completely degrade 1500 mg/L phenol in 80 h at 10 g/L NaCl. Meanwhile, mineralization of phenol was achieved with complete degradation of 900 mg/L phenol and simultaneously COD decreasing from 2239 mg/L to 181.6 mg/L in 36 h. Based on biodegradation metabolites identification and enzyme activities analysis, both ortho-cleavage pathway and benzoic acid pathway for phenol degradation were proposed. These findings suggested that SASS1 was an efficient phenol degrader under salinity and acidic conditions, and could be considered as key population for bioremediation of industrial phenolic wastewaters under stressful conditions.