FOOD SCIENCE
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YE Yu-dan,CHAI Chun-yan,LIU Guo-yan,WANG Yi-ru
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Abstract:
E. coli secretes β-galactosidase under the induction of isopropyl-β-D-thiogalactopyranoside (IPTG). The β-galacosidase catalyzes chlorophenol ReD-β-D-galactopyranoside (CPRG) to form chlorophenol red (CPR) along with a color reaction. Based on the significant correlation between intensity of the color change from the reaction and the concentration of E. coli, a photoelectric sensor for detecting E. coli was developed. The results showed that the optimal pH for the reaction system was 7.5 and the optimal time for enzymatic reaction was 4 h. The logarithm value of bacterial concentration in samples presented a significant correlation with the reflected light signal value (R = -0.98944, P < 0.01), the linear equation was Y = 1426.10485 - 97.23368X. The detection limit was 104 CFU/mL. The photoelectric sensor based on color reaction can provide a quick, simple and cheap way to detect E. coli in food samples and therefore deserves further development and application.
Key words: E.coli;photoelectronic sensor;&beta, -galactosidase;photoelectric test strip
YE Yu-dan,CHAI Chun-yan,LIU Guo-yan,WANG Yi-ru. Development of Photoelectric Sensor for Detection of E. coli[J]. FOOD SCIENCE, doi: 10.7506/spkx1002-6630-201318037.
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URL: https://www.spkx.net.cn/EN/10.7506/spkx1002-6630-201318037
https://www.spkx.net.cn/EN/Y2013/V34/I18/185