Abstract：
Amoebae are widespread in water and serve as environment vectors for pathogens, which may threaten public health. This study evaluated the inactivation of amoeba spores and their intraspore bacteria by solar/chlorine. Dictyostelium discoideum and Burkholderia agricolaris B1qs70 were selected as model amoebae and intraspore bacteria, respectively. Compared to solar irradiation and chlorine, solar/chlorine enhanced the inactivation of amoeba spores and intraspore bacteria, with 5.1 and 5.2-log reduction at 20 min, respectively. The enhancement was similar in real drinking water by solar/chlorine under natural sunlight. However, the spore inactivation decreased to 2.97-log by 20 min solar/chlorine under oxygen-free condition, indicating that ozone played a crucial role in the spore inactivation, as also confirmed by the scavenging test using tert‑butanol to scavenge the ground-state atomic oxygen (O(3P)) as a ozone precursor. Moreover, solar/chlorine induced the shape destruction and structural collapse of amoeba spores by scanning electron microscopy. As for intraspore bacteria, their inactivation was likely ascribed to endogenous reactive oxygen species. As pH increased from 5.0 to 9.0, the inactivation of amoeba spores decreased, whereas that of intraspore bacteria was similar at pH 5.0 and 6.5 during solar/chlorine treatment. This study first reports the efficient inactivation of amoeba spores and their intraspore pathogenic bacteria by solar/chlorine in drinking water.
摘要：
变形虫广泛存在于水中,是病原体的环境载体,这可能会威胁到公众健康。这项研究评估了太阳能/氯对变形虫孢子及其孢子内细菌的灭活作用。选择盘基网柄菌和农业伯克霍尔德菌B1qs70作为模型变形虫和孢子内细菌，分别。与太阳辐射和氯相比，太阳能/氯增强了变形虫孢子和孢子内细菌的失活，在20分钟时减少5.1和5.2-log，分别。在自然阳光下，太阳能/氯气在实际饮用水中的增强作用类似。然而,在无氧条件下，通过20分钟的太阳能/氯气，孢子失活降低到2.97-log，表明臭氧在孢子失活中起着至关重要的作用，使用叔丁醇清除基态原子氧（O（3P））作为臭氧前体的清除试验也证实了这一点。此外，通过扫描电子显微镜，太阳能/氯引起变形虫孢子的形状破坏和结构崩溃。至于孢子内细菌，它们的失活可能归因于内源性活性氧。随着pH从5.0增加到9.0，变形虫孢子的失活减少，而在太阳能/氯处理期间，在pH5.0和6.5时，孢子内细菌的细菌相似。本研究首次报道了饮用水中太阳能/氯对变形虫孢子及其孢子内致病菌的有效灭活作用。
