Development of an online biosensor for in situ monitoring of chlorine dioxide gas disinfection efficacy.
A prototype bioluminescence-based biosensor was designed and constructed to evaluate the antimicrobial efficacy of chlorine dioxide (ClO(2)) gas under various treatment conditions. The biosensor consisted of a bioluminescent bioreporter (Pseudomonas fluorescens 5RL), an optical transducer (photomultiplier tube), and a light-tight chamber housing, the bioreporter and the transducer. The bioluminescent recombinant P. fluorescens 5RL in the biosensor allowed for online monitoring of bioluminescence during ClO(2) gas disinfection. Experiments were performed to evaluate the effects of the two key physical parameters associated with ClO(2) disinfection: relative humidity (40, 60, 80%) and ClO(2) gas concentration (0.5, 1.0, 1.6, 2.1 mg/l) on the bioreporter. Results showed that increasing concentrations of ClO(2) gas corresponded to a faster decrease in luminescence. The rates of luminescence decrease from P. fluorescens 5RL, and the log reduction time (LRT, time required to obtain 1-log reduction in luminescence) were calculated for each treatment tested. The LRT values of luminescence were 103, 78, 53, and 35 s for 0.5, 1.0, 1.6, and 2.1 mg/l of ClO(2) gas treatment, respectively, at 78% relative humidity. The gas concentration which caused a tenfold change in LRT (z value) for luminescence of P. fluorescens 5RL was 3.4 mg/l of ClO(2). The prototype biosensor showed potential for many applications, such as monitoring real-time microbial inactivation and understanding parameters that influence the efficacy of gaseous decontamination procedures.
del Busto-Ramos
Maria
M
Department of Food Science, Purdue University, 745 Agriculture Mall Dr., West Lafayette, IN 47907-2009, USA.
Budzik
Michael
M
Corvalan
Carlos
C
Morgan
Mark
M
Turco
Ronald
R
Nivens
David
D
Applegate
Bruce
B
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D017606:Chlorine Compounds / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection; D004305:Dose-Response Relationship, Drug; D005516:Food Microbiology; D006813:Humidity; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods*; D050296:Microbial Viability / Q000187:drug effects; D010087:Oxides / Q000494:pharmacology*; D011551:Pseudomonas fluorescens / Q000187:drug effects* / Q000378:metabolism
D017606:Chlorine Compounds; D004202:Disinfectants; D010087:Oxides; C025109:chlorine dioxide