title: Sunlight inactivation of somatic coliphage in the presence of natural organic matter.
abstract: Long wavelengths of sunlight spectrum (UVA and visible light), as well as natural organic matter (NOM) are important environmental factors affecting survival of viruses in aquatic environment through direct and indirect inactivation. In order to understand the virus inactivation kinetics under such conditions, this study investigated the effects of Suwannee River natural organic matter (NOM) on the inactivation of a somatic coliphage, phiX174, by UVA and visible light. Experiments were carried out to examine the virucidal effects of UVA/visible light, assess the influence of SRNOM at different concentrations, and identify the effective ROS in virus inactivation. The results from this study showed that the presence of NOM could either enhance virus inactivation or reduce virus inactivation depending on the concentration, where the inactivation rate followed a parabolic relationship against NOM concentration. The results indicated that moderate levels of NOM (11 ppm) had the strongest antiviral activity, while very low or very high NOM concentrations prolonged virus survival. The results also showed that OH▪ was the primary ROS in causing phiX174 (ssDNA virus) inactivation, unlike previous findings where (1)O2 was the primary ROS causing MS2 (ssRNA virus) inactivation. The phiX174 inactivation by OH∙ could be described as k=3.7 ✕ 10(13)[OH∙]+1.404 (R(2)=0.8527).
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
authors.forename: Chen-Xi
authors.initials: CX
authors.lastname: Sun
authors.affiliation: Center for Environmental Sensing and Modeling, Singapore-MIT Alliance for Research and Technology, Singapore.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kitajima
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore; NUS Environmental Research Institute, National University of Singapore, Singapore. Electronic address: ceeginyh@nus.edu.sg.
authors.forename: Karina Yew-Hoong
authors.initials: KY
authors.lastname: Gin
mesh_terms: D003090:Coliphages / Q000502:physiology*; D006812:Humic Substances; D007700:Kinetics; D045483:Rivers / Q000821:virology; D013472:Sunlight; D038301:Virus Inactivation
chemical_list: D006812:Humic Substances
keywords: DNA virus; NOM; Somatic coliphage; Sunlight inactivation; phiX174