【摘要】：由于流經(jīng)蘭州的黃河被重金屬和多環(huán)芳烴嚴(yán)重污染,因此將多環(huán)芳烴的降解和重金屬的還原結(jié)合在一起治理污染的策略將成為一種重要的新思路應(yīng)用在未來(lái)蘭州地區(qū)治理土壤和水污染。通過(guò)在污染的河流附近的淤泥采樣,能夠在有氧條件下降解萘和還原金屬鉻的LZ-4號(hào)菌株被分離出來(lái)。隨后,其在不同碳源下還原六價(jià)鉻的能力被檢測(cè)。當(dāng)加入200μM或500 μM六價(jià)鉻進(jìn)入培養(yǎng)基后,以萘為唯一碳源的LZ-4號(hào)菌株幾乎還原全部的六價(jià)鉻為三價(jià)鉻。當(dāng)在培養(yǎng)基中加入1mM六價(jià)鉻后,以萘為唯一碳源的LZ-4號(hào)菌株能夠還原42%的六價(jià)鉻為三價(jià)鉻。然而,無(wú)論在上述哪一種濃度的鉻加入培養(yǎng)基后,以葡萄糖為碳源的LZ-4號(hào)菌株僅僅只能還原22%的六價(jià)鉻。通過(guò)全基因組測(cè)序,化學(xué)反應(yīng)實(shí)驗(yàn)以及酶活相關(guān)實(shí)驗(yàn),我們嘗試解釋這一有趣的現(xiàn)象。同樣,部分參與降解萘的酶,如NahG和NahE都被純化和結(jié)晶,并通過(guò)酶活實(shí)驗(yàn)來(lái)驗(yàn)證其是否具有還原金屬鉻的能力。這種同時(shí)降解萘還原鉻的方法和機(jī)制將為未來(lái)篩選改造工程菌株提供指導(dǎo),同時(shí)也能為未來(lái)治理多環(huán)芳烴污染和重金屬污染提供新見(jiàn)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.
【學(xué)位授予單位】：蘭州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X172

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1 陶玄宇;萘促進(jìn)熒光假單胞菌LZ-4還原六價(jià)鉻的機(jī)理探索及相關(guān)萘降解蛋白的純化和結(jié)晶[D];蘭州大學(xué);2015年

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