title: Solar inactivation of faecal bacteria in water: the critical role of oxygen.
abstract: Suspensions of the faecal indicator bacteria Escherichia coli and Enterococcus faecalis were incubated in full sunlight in plastic bottles containing either (i) air-equilibrated (oxygenated) water or (ii) anaerobic (deoxygenated) water. A rapid decrease in cfu ml-1 was observed for actively growing and stationary phase cells of both types of faecal bacteria when illuminated under aerobic conditions, with Ent. faecalis showing the greater enhancement in the rate of inactivation in air-equilibrated water. The demonstration of an oxygen requirement for the inactivation of faecal bacteria in sunlight indicates that solar-based water disinfection systems are likely to require fully aerobic conditions in order to function effectively.
authors.affiliation: Department of Chemical & Life Sciences, University of Northumbria at Newcastle, Newcastle upon Tyne, UK.
authors.forename: R H
authors.initials: RH
authors.lastname: Reed
mesh_terms: D000332:Aerobiosis; D001419:Bacteria / Q000378:metabolism* / Q000528:radiation effects*; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D013293:Enterococcus faecalis / Q000378:metabolism / Q000528:radiation effects; D004926:Escherichia coli / Q000378:metabolism / Q000528:radiation effects; D005069:Evaluation Studies as Topic; D005243:Feces / Q000382:microbiology; D006801:Humans; D066298:In Vitro Techniques; D010100:Oxygen / Q000378:metabolism*; D013472:Sunlight; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D010100:Oxygen