[ Objective] Based on salicylic acid culture solution, high performance liquid chromatography （HPLC） was used to rapidly count E. coli in water. [Method] Because E. coli metabolism could produce polyatomic phenol （...[ Objective] Based on salicylic acid culture solution, high performance liquid chromatography （HPLC） was used to rapidly count E. coli in water. [Method] Because E. coli metabolism could produce polyatomic phenol （mainly 2, 5-dihydroxybenzoic acid） in salicylic acid culture solu- tion, and generated amount of polyatomic phenol was proportionate to the number of E. coli, we detected 2, 5-dihydroxybenzoic acid by HPLC. Through linear relationship, the number of E. co/i was calculated, realizing fast counting of E. coli, and detection time only needed 3 h. [ Result] Linearity range of the method detecting E. coli was 5 × 10^4 -5 × 10^10cells/ml, and the detection limit was 1 × 10^4 cells/ml. [ Conclusion] HPLC method realized rapid counting of E. coil Key words E. coli; Fast counting; HPLC; Salicylic acid; China展开更多
[Objective] The aim was to study on influence of ultrasonic on broken effect of foodborne polluting strains.[Method] Escherichia coli,Staphylococcus aureus,and Aspergillus niger in different concentrations were tested...[Objective] The aim was to study on influence of ultrasonic on broken effect of foodborne polluting strains.[Method] Escherichia coli,Staphylococcus aureus,and Aspergillus niger in different concentrations were tested in different ultrasonic powers and times for the broken effects.[Result] Escherichia coli and Staphylococcus aureus were more sensitive to ultrasonication and the broken rates were as high as 96%.Aspergillus niger,however,was not so sensitive and the broken rate was only about 40%.The optimum parameters,including ultrasonic power,ultrasonic time and OD,of Escherichia coli were 600 W,14 min and 0.997,of Staphylococcus aureus were 600 W,15 min and 1.440,and of Aspergillus niger were 700 W,20 min and 0.893,respectively.[Conclusion] The research provided references for application of ultrasonic technology in food sterilization.展开更多
基金Supported by Plan Item of National Bureau of Quality Inspection,China(2011QK345)Natural Science Foundation Item of Guangxi,China(Guikezi0728048)
文摘[ Objective] Based on salicylic acid culture solution, high performance liquid chromatography （HPLC） was used to rapidly count E. coli in water. [Method] Because E. coli metabolism could produce polyatomic phenol （mainly 2, 5-dihydroxybenzoic acid） in salicylic acid culture solu- tion, and generated amount of polyatomic phenol was proportionate to the number of E. coli, we detected 2, 5-dihydroxybenzoic acid by HPLC. Through linear relationship, the number of E. co/i was calculated, realizing fast counting of E. coli, and detection time only needed 3 h. [ Result] Linearity range of the method detecting E. coli was 5 × 10^4 -5 × 10^10cells/ml, and the detection limit was 1 × 10^4 cells/ml. [ Conclusion] HPLC method realized rapid counting of E. coil Key words E. coli; Fast counting; HPLC; Salicylic acid; China
文摘[Objective] The aim was to study on influence of ultrasonic on broken effect of foodborne polluting strains.[Method] Escherichia coli,Staphylococcus aureus,and Aspergillus niger in different concentrations were tested in different ultrasonic powers and times for the broken effects.[Result] Escherichia coli and Staphylococcus aureus were more sensitive to ultrasonication and the broken rates were as high as 96%.Aspergillus niger,however,was not so sensitive and the broken rate was only about 40%.The optimum parameters,including ultrasonic power,ultrasonic time and OD,of Escherichia coli were 600 W,14 min and 0.997,of Staphylococcus aureus were 600 W,15 min and 1.440,and of Aspergillus niger were 700 W,20 min and 0.893,respectively.[Conclusion] The research provided references for application of ultrasonic technology in food sterilization.
