萘促进荧光假单胞菌LZ-4还原六价铬的机理探索及相关萘降解蛋白的纯化和结晶
发布时间：2019-01-05 12:51
【摘要】：由于流经兰州的黄河被重金属和多环芳烃严重污染,因此将多环芳烃的降解和重金属的还原结合在一起治理污染的策略将成为一种重要的新思路应用在未来兰州地区治理土壤和水污染。通过在污染的河流附近的淤泥采样,能够在有氧条件下降解萘和还原金属铬的LZ-4号菌株被分离出来。随后,其在不同碳源下还原六价铬的能力被检测。当加入200μM或500 μM六价铬进入培养基后,以萘为唯一碳源的LZ-4号菌株几乎还原全部的六价铬为三价铬。当在培养基中加入1mM六价铬后,以萘为唯一碳源的LZ-4号菌株能够还原42%的六价铬为三价铬。然而,无论在上述哪一种浓度的铬加入培养基后,以葡萄糖为碳源的LZ-4号菌株仅仅只能还原22%的六价铬。通过全基因组测序,化学反应实验以及酶活相关实验,我们尝试解释这一有趣的现象。同样,部分参与降解萘的酶,如NahG和NahE都被纯化和结晶,并通过酶活实验来验证其是否具有还原金属铬的能力。这种同时降解萘还原铬的方法和机制将为未来筛选改造工程菌株提供指导,同时也能为未来治理多环芳烃污染和重金属污染提供新见解。
[Abstract]:The Yellow River, which flows through Lanzhou, is heavily polluted by heavy metals and polycyclic aromatic hydrocarbons (PAHs). Therefore, combining the degradation of polycyclic aromatic hydrocarbons (PAHs) with the reduction of heavy metals to control pollution will become an important new way to control soil and water pollution in Lanzhou area in the future. By sampling sludge near polluted rivers, strain LZ-4, which can degrade naphthalene and reduce chromium under aerobic conditions, was isolated. Subsequently, its ability to reduce hexavalent chromium under different carbon sources was tested. When 200 渭 M or 500 渭 M hexavalent chromium was added into the medium, LZ-4 strain with naphthalene as the sole carbon source reduced almost all hexavalent chromium to trivalent chromium. When 1mM hexavalent chromium was added to the medium, LZ-4 strain with naphthalene as the sole carbon source could reduce 42% hexavalent chromium to trivalent chromium. However, no matter which of the above concentrations of chromium was added to the medium, LZ-4 strain with glucose as carbon source could only reduce only 22% of hexavalent chromium. We try to explain this interesting phenomenon by genome sequencing, chemical reaction and enzyme activity related experiments. Similarly, some of the enzymes involved in the degradation of naphthalene, such as NahG and NahE, were purified and crystallized. The method and mechanism of simultaneous degradation of chromium from naphthalene will provide guidance for the screening and modification of engineering strains in the future, as well as new ideas for the treatment of polycyclic aromatic hydrocarbons (PAHs) and heavy metal pollution in the future.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172
本文编号：2401802
[Abstract]:The Yellow River, which flows through Lanzhou, is heavily polluted by heavy metals and polycyclic aromatic hydrocarbons (PAHs). Therefore, combining the degradation of polycyclic aromatic hydrocarbons (PAHs) with the reduction of heavy metals to control pollution will become an important new way to control soil and water pollution in Lanzhou area in the future. By sampling sludge near polluted rivers, strain LZ-4, which can degrade naphthalene and reduce chromium under aerobic conditions, was isolated. Subsequently, its ability to reduce hexavalent chromium under different carbon sources was tested. When 200 渭 M or 500 渭 M hexavalent chromium was added into the medium, LZ-4 strain with naphthalene as the sole carbon source reduced almost all hexavalent chromium to trivalent chromium. When 1mM hexavalent chromium was added to the medium, LZ-4 strain with naphthalene as the sole carbon source could reduce 42% hexavalent chromium to trivalent chromium. However, no matter which of the above concentrations of chromium was added to the medium, LZ-4 strain with glucose as carbon source could only reduce only 22% of hexavalent chromium. We try to explain this interesting phenomenon by genome sequencing, chemical reaction and enzyme activity related experiments. Similarly, some of the enzymes involved in the degradation of naphthalene, such as NahG and NahE, were purified and crystallized. The method and mechanism of simultaneous degradation of chromium from naphthalene will provide guidance for the screening and modification of engineering strains in the future, as well as new ideas for the treatment of polycyclic aromatic hydrocarbons (PAHs) and heavy metal pollution in the future.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172
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1 陶玄宇;萘促进荧光假单胞菌LZ-4还原六价铬的机理探索及相关萘降解蛋白的纯化和结晶[D];兰州大学;2015年
，本文编号：2401802
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