Mineralization of Bacterial Cell Mass on a Photocatalytic Surface in Air

• Published in: Environmental science & technology 1998-09, Vol.32 (17), p.2650-2653
• Main Authors: Jacoby, William A, Maness, Pin Ching, Wolfrum, Edward J, Blake, Daniel M, Fennell, John A
• Format: Article
• Language: English
• Subjects: Applied sciences; Atmospheric pollution; Bacteria; Biological and medical sciences; Biotechnology; Carbon dioxide; Catalysis; Cells; Environment and pollution; Environmental impact; Environmental protection; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Genetically engineered organisms behavior (microorganisms, plants, animals); Indoor pollution and occupational exposure; Industrial applications and implications. Economical aspects; Oxidation; photocatalysis; Pollution; Scanning electron microscopy; Sterilization; Titanium dioxide
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es980036f

Whole cells deposited on a titanium dioxide-coated surface have been oxidized in air to carbon dioxide via photocatalysis. This paper provides the first evidence that the organic matter in whole cells can be completely oxidized. Three experimental techniques were employed to monitor this reaction:  scanning electron microscopy,14C radioisotope labeling, and batch reactor measurements. The scanning electron microscopy experiments illustrate the disappearance of Escherichia coli cell mass. The 14C radioisotope labeling experiments establish that the carbon content of E. coli is oxidized to form carbon dioxide with substantial closure of the mass balance. The batch reactor experiments corroborate the mass balance and provide a preliminary indication of the rate of the oxidation reaction. These results provide evidence that a photocatalytic surface used for disinfection can also be self-cleaning in an air−solid system.