Enhanced Inactivation of Bacillus subtilis Spores during Solar Photolysis of Free Available Chlorine
Enhanced Inactivation of Bacillus subtilis Spores during Solar Photolysis of Free Available Chlorine
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DOI：
10.1021/es401906x
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发表时间：
2013-11-19
影响因子：
11.4
通讯作者：
Dodd, Michael C.
中科院分区：
文献类型：
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作者：
Forsyth, Jenna E.;Zhou, Peiran;Dodd, Michael C.
水溶液中的游离有效氯（FAC）在太阳光和/或人工紫外光的作用下可以发生光解，产生各种活性氧，包括HO中心点和O（P-3）。以枯草芽孢杆菌内生孢子为模型微生物菌剂，模拟和自然太阳辐射为光源，研究了这种化学方法对耐氯微生物失活的影响。FAC溶液的辐照显著增强了B的失活。枯草芽孢杆菌孢子在10 μ M磷酸盐缓冲液中的灭活速率常数增加了600%，灭活曲线滞后期缩短了73%，在pH 8.0和10 ℃下，2 log（10）灭活所需的CT降低了71%。在pH 7.4和10摄氏度的两个饮用水样品中观察到类似的结果，DOC浓度和碱度分别为0.6和1.2毫克C/L和81.8和17.1毫克/L的碳酸钙。单独的太阳辐射不能使B增加。枯草芽孢杆菌孢子在研究的条件下。各种实验数据表明，所观察到的增强孢子灭活可以归因于伴随的攻击孢子HO中心点和O-3，后者被发现积累到微摩尔浓度在模拟太阳辐射的10英寸M磷酸盐缓冲液（pH 8，10摄氏度）含有[FAC]（0）= 8毫克/升的Cl-2。
Aqueous free available chlorine (FAC) can be photolyzed by sunlight and/or artificial UV light to generate various reactive oxygen species, including HO center dot and O(P-3). The influence of this chemistry on inactivation of chlorine-resistant microorganisms was investigated using Bacillus subtilis endospores as model microbial agents and simulated and natural solar radiation as light sources. Irradiation of FAC solutions markedly enhanced inactivation of B. subtilis spores in 10 inM phosphate buffer; increasing inactivation rate constants by as much as 600%, shortening inactivation curve lag phase by up to 73% and lowering CTs required for 2 log(10) inactivation by as much as 71% at pH 8.0 and 10 degrees C. Similar results were observed at pH 7.4 and 10 degrees C in two drinking water samples with respective DOC concentrations and alkalinities of 0.6 and 1.2 mg C/L and 81.8 and 17.1 mg/L as CaCO3. Solar radiation alone did not inactivate B. subtilis spores under the conditions investigated. A variety of experimental data indicate that the observed enhancements in spore inactivation can be attributed to the concomitant attack of spores by HO center dot and O-3, the latter of which was found to accumulate to micromolar concentrations during simulated solar irradiation of 10 in.M phosphate buffer (pH 8, 10 degrees C) containing [FAC](0) = 8 mg/L as Cl-2.