Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
Int J Environ Res Public Health. 2019 Nov 27;16(23):4745. doi: 10.3390/ijerph16234745.
Bioaerosol generated in wastewater treatment plants has potential to harm human health. Survival of bacteria in bioaerosol during suspension is one of the major factors that affect its biological risk. It is hypothesized that bacteria grown in different wastewater have different physiology and lead to variation in airborne survival. This study investigated the relationship between the cultured conditions and the bioaerosol survival. Synthetic wastewater was used as the culture medium to simulate the water quality of wastewater. BW25113 were cultured in different conditions, including growth salinity, growth temperature, growth pH, and presence of pesticide. The fatty acid composition and the reduction in airborne survival of the cultured under these conditions were determined and compared. Results showed that increasing growth salinity and temperature led to a lower reduction in airborne survival of cultured at pH 6 had a higher reduction in airborne survival than those cultured at pH 7 and 8. Moreover, a correlation was observed between the membrane fluidity (fluidity index) and the reduction airborne survival for both aerosolization and airborne suspension. A link between culture conditions, bacterial membrane fluidity, and airborne survival was established. Culture conditions (wastewater quality) that lead to a low membrane fluidity of bacteria increase the airborne survival of bioaerosol, and vice versa. This provides a new aspect to evaluate bioaerosol survival and improve assessment on biological risk of bioaerosols.
污水处理厂产生的生物气溶胶有可能危害人类健康。悬浮状态下生物气溶胶中细菌的存活是影响其生物风险的主要因素之一。据推测，在不同废水中生长的细菌具有不同的生理学特性，从而导致其在空气中的存活能力存在差异。本研究调查了培养条件与生物气溶胶存活之间的关系。采用合成废水作为培养基，模拟废水水质。将 BW25113 在不同条件下进行培养，包括生长盐度、生长温度、生长 pH 值和农药存在情况。测定并比较了这些条件下培养的细菌的脂肪酸组成和空气中存活能力的降低情况。结果表明，生长盐度和温度的增加导致培养物在 pH 值为 6 时的空气中存活能力降低程度较低，而在 pH 值为 7 和 8 时则较低。此外，还观察到气溶胶化和空气悬浮培养物的膜流动性（流动性指数）与空气中存活能力降低之间存在相关性。建立了培养条件、细菌膜流动性和空气中存活能力之间的联系。导致细菌膜流动性降低的培养条件（废水质量）会增加生物气溶胶的空气中存活能力，反之亦然。这为评估生物气溶胶存活能力提供了一个新的方面，并提高了对生物气溶胶生物风险的评估。
