title: Response surface modeling for the inactivation of Bacillus subtilis subsp. niger spores by chlorine dioxide gas in an enclosed space.
abstract: Bacillus subtilis subsp. niger spores are a commonly used biological indicator to evaluate the disinfection of an enclosed space. In the present study, chlorine dioxide (ClO2) gas was applied to inactivate B. subtilis subsp. niger spores in an enclosed space. The effects of the ClO2 gas concentration (1-3 mg/l), relative humidity (RH, 30-70%) and exposure time (30-90 min) were investigated using a response surface methodology (RSM). A three-factor Box-Behnken experimental design was used. The obtained data were adequately fitted to a second-order polynomial model with an R2adj of 0.992. The ClO2 gas concentration, RH and exposure time all significantly (P<0.05) and positively correlated with the inactivation of B. subtilis subsp. niger spores. The interaction between the ClO2 gas concentration and RH as well as that between the exposure time and RH indicated significant and synergistic effects (P<0.05). The predictive model was validated by additional eight experiments and proven to be with good accuracy. Overall, this model established by the RSM could show the trend of the inactivation of spores, indicate the interactions between important factors, and provide a reference to determine effective conditions for the disinfection in different enclosed spaces by ClO2 gas.
  
  
  CONCLUSIONS
  The inactivation of indoor biological contaminants plays an important role in preventing the transmission of pathogens and ensuring human safety. The predictive model using response surface methodology indicates the influence and interaction of the main factors on the inactivation of Bacillus subtilis subsp. niger spores by ClO2 gas, and can predict a ClO2 gas treatment condition to achieve an effective sterilization of enclosed spaces. The results in this paper will provide a reference for the application of ClO2 gas treatments for indoor disinfection.
authors: a Institute of Medical Equipment, Academy of Military Medical Sciences , Tianjin , People's Republic of China.|b National Bio-protection Engineering Center , Tianjin , People's Republic of China.
authors: Tao
authors: T
authors: Wang
authors: a Institute of Medical Equipment, Academy of Military Medical Sciences , Tianjin , People's Republic of China.|b National Bio-protection Engineering Center , Tianjin , People's Republic of China.
authors: Jiancheng
authors: J
authors: Qi
authors: a Institute of Medical Equipment, Academy of Military Medical Sciences , Tianjin , People's Republic of China.|b National Bio-protection Engineering Center , Tianjin , People's Republic of China.
authors: Jinhui
authors: J
authors: Wu
authors: a Institute of Medical Equipment, Academy of Military Medical Sciences , Tianjin , People's Republic of China.|b National Bio-protection Engineering Center , Tianjin , People's Republic of China.
authors: Limei
authors: L
authors: Hao
authors: a Institute of Medical Equipment, Academy of Military Medical Sciences , Tianjin , People's Republic of China.|b National Bio-protection Engineering Center , Tianjin , People's Republic of China.
authors: Ying
authors: Y
authors: Yi
authors: a Institute of Medical Equipment, Academy of Military Medical Sciences , Tianjin , People's Republic of China.|b National Bio-protection Engineering Center , Tianjin , People's Republic of China.
authors: Song
authors: S
authors: Lin
authors: a Institute of Medical Equipment, Academy of Military Medical Sciences , Tianjin , People's Republic of China.|b National Bio-protection Engineering Center , Tianjin , People's Republic of China.
authors: Zongxing
authors: Z
authors: Zhang
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects*; D017606:Chlorine Compounds / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D008962:Models, Theoretical; D010087:Oxides / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000187:drug effects
chemical_list: D017606:Chlorine Compounds; D004202:Disinfectants; D010087:Oxides; C025109:chlorine dioxide