Rapid detection of bacteria without cultivation with a portable bioluminescence sensor system

Based on the principle of ATP bioluminescence reaction, we designed a portable bioluminescence sensor system to detect bacteria in samples rapidly, which included an optical sensing cell, a flow injection unit and a center processing unit. A fast ATP extraction technique was developed by using trichloroacetic acid (TCA) as extraction reagent. Experimental results showed that the intracellular ATP could be released from bacterial cells sufficiently within 5 min by TCA. In the presence of luciferase, the reaction between ATP and luciferin would generate light and the luminescence intensity (RLU) was proportional to the amount of bacteria exsited in the sample. The dynamic range of the sensor system ranged from 10 - 10(7) CFU/ml. The linear regression coefficient was 0.976, and the detection limit was 10 CFU/ml. The whole testing time needed was about 10 min. Compared with the plate count method, bacteria concentration in samples could be detected rapidly by using this portable sensor system without cultivation.