Protein Denaturation Piezoelectric Frequency Shift Method for Determination of Microorganisms

✍ Scribed by Lili Bao; Xiaoge Qu; Shouzhuo Yao; Wanzhi Wei

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 62 KB
• Volume: 62
• Category: Article
• ISSN: 0026-265X
• DOI: 10.1006/mchj.1999.1736

✦ Synopsis

A protein denaturation piezoelectric frequency shift method was used to determine the number of bacteria based on the influence of bacterium metabolism on milk. Compared with methods presented earlier based on coagulation of the medium it was more rapid, as less than half an hour was needed for detection after a preincubation of several hours. The proposed method was used to determine Escherichia coli. The end-point frequency shift was linearly related to the logarithm of the initial number of E. coli in the range 1.4 ϫ 10 2 -1.4 ϫ 10 5 cells ⅐ ml Ϫ1 . Calibration graphs of E. coli and Micrococcus lysodeikeicus were compared; the results may be helpful for the qualitative analysis of various bacteria. Finally, changes in milk freshness was monitored by this method.