Objective： Chlorine dioxide （CD） gas has been used as a fumigant in the disinfection of biosafety labo- ratories. In this study, some experiments were conducted to assess the inactivation of spores inoculated on si...Objective： Chlorine dioxide （CD） gas has been used as a fumigant in the disinfection of biosafety labo- ratories. In this study, some experiments were conducted to assess the inactivation of spores inoculated on six ma- terials [stainless steel （SS）, painted steel （PS）, polyvinyl chlorid （PVC）, polyurethane （PU）, glass （GS）, and cotton cloth （CC）] by CD gas. The main aims of the study were to determine the sporicidal efficacy of CD gas and the effect of prehumidification before decontamination on sporicidal efficacy. Methods： Material coupons （1.2 cm diameter of SS, PS, and PU; 1.0 cmx1.0 cm for PVC, GS, and CC） were contaminated with 10 IJI of Bacillus subtilis var. niger（ATCC 9372） spore suspension in mixed organic burden and then dried in a biosafety cabinet for 12 h. The spores were recovered by soaking the coupons in 5 ml of extraction liquid for 1 h and then vortexing the liquid for 1 min. Results： The log reductions in spore numbers on inoculated test materials exposed to CD gas [0.080% （volume ratio, v/v） for 3 h] were in the range of from 1.80 to 6.64. Statistically significant differences were found in decontamination efficacies on test material coupons of SS, PS, PU, and CC between with and without a 1-h prehumidification treatment. With the extraction method, there were no statistically significant differences in the recovery ratios between the porous and non-porous materials. Conclusions： The results reported from this study could provide information for developing decontamination technology based on CD gas for targeting surface microbial contamination.展开更多
A preliminary study on the mutation breeding of an organic phosphorus-solubilizing bacterium B3 by low-energy N^＋ ion beam was conducted. Analysis of dosage vs. survival rate and mutation rate showed that the dosage ...A preliminary study on the mutation breeding of an organic phosphorus-solubilizing bacterium B3 by low-energy N^＋ ion beam was conducted. Analysis of dosage vs. survival rate and mutation rate showed that the dosage of 3×10^15 ions/cm^2 was optimal for the mutation. Some parameters for determining the efficient phosphorus content were studied to simplify the protocols for screening. Ultimately one reliable mutant was screened out under plating and flask-culturing screening conditions. Importantly, a novel phosphorus-dissolving mechanism is reported for the first time in terms of bio-surfactant production, which indicates that bio-surfactant might play a vital role in phosphorus-dissolving for some phosphobacteria.展开更多
基金Project supported by the National Key Science and Technology Specific Project for Prevention and Treatment of Major Infectious Diseases in China (No. 2009ZX10004-709)the National Key Technology R&D Program in the 11th Five-Year Plan of China (No.2008BAI62B01)
文摘Objective： Chlorine dioxide （CD） gas has been used as a fumigant in the disinfection of biosafety labo- ratories. In this study, some experiments were conducted to assess the inactivation of spores inoculated on six ma- terials [stainless steel （SS）, painted steel （PS）, polyvinyl chlorid （PVC）, polyurethane （PU）, glass （GS）, and cotton cloth （CC）] by CD gas. The main aims of the study were to determine the sporicidal efficacy of CD gas and the effect of prehumidification before decontamination on sporicidal efficacy. Methods： Material coupons （1.2 cm diameter of SS, PS, and PU; 1.0 cmx1.0 cm for PVC, GS, and CC） were contaminated with 10 IJI of Bacillus subtilis var. niger（ATCC 9372） spore suspension in mixed organic burden and then dried in a biosafety cabinet for 12 h. The spores were recovered by soaking the coupons in 5 ml of extraction liquid for 1 h and then vortexing the liquid for 1 min. Results： The log reductions in spore numbers on inoculated test materials exposed to CD gas [0.080% （volume ratio, v/v） for 3 h] were in the range of from 1.80 to 6.64. Statistically significant differences were found in decontamination efficacies on test material coupons of SS, PS, PU, and CC between with and without a 1-h prehumidification treatment. With the extraction method, there were no statistically significant differences in the recovery ratios between the porous and non-porous materials. Conclusions： The results reported from this study could provide information for developing decontamination technology based on CD gas for targeting surface microbial contamination.
基金Hubei Technologies R&D Program of China(No.2007AA201C28)the Ministry of Science and Technology of China Microbial Resources Project(No.2005DKA21208-6)Open Project of State Key Laboratory of Agricultural Microbiology of China
文摘A preliminary study on the mutation breeding of an organic phosphorus-solubilizing bacterium B3 by low-energy N^＋ ion beam was conducted. Analysis of dosage vs. survival rate and mutation rate showed that the dosage of 3×10^15 ions/cm^2 was optimal for the mutation. Some parameters for determining the efficient phosphorus content were studied to simplify the protocols for screening. Ultimately one reliable mutant was screened out under plating and flask-culturing screening conditions. Importantly, a novel phosphorus-dissolving mechanism is reported for the first time in terms of bio-surfactant production, which indicates that bio-surfactant might play a vital role in phosphorus-dissolving for some phosphobacteria.
