Photoinactivation of Staphylococcus aureus and Vibrio parahaemolyticus in the model aquatic microcosm: effect of light intensity and dissolved biodegradable organic compound.
The impact of light (1,000 × 100,000 lx) on the inactivation of S. aureus and V. parahaemolyticus has been assessed under different concentrations of dissolved biodegradable organic compound (BOC) at pH 7.0. First, a gradual decrease in the number of cultivable cells was observed. Secondly, a cell reactivation was observed and it was marked in the absence of BOC. In the absence of BOC, the lowest value of cell inhibition rate (CIR) during the first 3 h was 0.138 h(-1) for S. aureus and 0.218 h(-1) for V. parahaemolyticus. In the presence of 10,100 and 1,000 mg/l of BOC, it was 0.196 h(-1), 0.243 h(-1) and 0.257 h(-1) for S. aureus respectively, and 0.285 h(-1), 0.306 h(-1) and 0.409 h(-1) for V. parahaemolyticus respectively. The CIRs values of each bacterial species significantly varied (P<0.001) with the changes in BOC concentration. In most cases, no significant difference was noted in the CIRs of both species when they were under the same light intensity and BOC. Nevertheless, it seems important to consider the impact of dissolved BOC during the treatment of bacterial polluted water.
Laboratory of General Biology, University of Yaounde 1, Yaounde, Cameroon. moise.nola@yahoo.com
Moïse
M
Nola
Armelle G Simo
AG
Matchim
Olga Blanche
OB
Mobili
Mireille
M
Nougang
François
F
Krier
Nour-Eddine
NE
Chihib
Jean-Pierre
JP
Hornez
Thomas
T
Njiné
D005947:Glucose / Q000032:analysis; D006812:Humic Substances / Q000032:analysis*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010782:Photolysis; D012995:Solubility; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D014466:Ultraviolet Rays; D014736:Vibrio parahaemolyticus / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
D006812:Humic Substances; D005947:Glucose