Biotechnology Bulletin ›› 2023, Vol. 39 ›› Issue (12): 90-98.doi: 10.13560/j.cnki.biotech.bull.1985.2023-0129

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Establishment of a Luciferase-assisted Quantitative Method for Measuring Ultrasonic Disruption of Escherichia coli Cells

LI Yi-ya1(), WU Yi-fan1, DING Neng-shui2, FAN Xiao-ping2, CHEN Fan1()   

  1. 1. School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000
    2. Fujian Aonong Biological Science and Technology Group Co. Ltd, Zhangzhou 363000
  • Received:2023-02-15 Online:2023-12-26 Published:2024-01-11
  • Contact: CHEN Fan E-mail:lyy@bio.mnnu.edu.cn;cf@bio.mnnu.edu.cn

Abstract:

In this study, we present a novel and effective method for measuring ultrasonic disruption of Escherichia coli cells based on firefly luciferase. This quantitative approach provides high sensitivity and rapid detection of cell disruption, by which the disruption was characterized. To evaluate this method, we employed an E. coli strain expressing firefly luciferase as an internal reference, which was mixed with the target bacterial suspension at a specific ratio before sonication. The release of both luciferase and target protein activities into the extracellular solution under different ultrasonic conditions was then investigated, and the assisted quantitative effect was evaluated. The results demonstrated that: A ratio of 1∶500(volume ratio)E. coli strain expressing firefly luciferase added to the target bacterial suspension was sufficient for sonication quantification. The effect of sonication was calculated by the change of luciferase activity within the supernatant. Importantly, luciferase activity also provided clues for maintaining target protein activity during sonication. The luciferase protein incorporated into the final supernatant showed no effect on the purification of the target protein by nickel beads. Bacteria containing firefly luciferase can be stored at -80℃ for at least 90 d without significant loss of luciferase activity. Moreover, the disruption resistance was not changed during the long-term cryo-storage process. Therefore, freezing bacterial suspension can be thawed and directly mixed with target cells for assisting quantification without losing accuracy. In conclusion, the luciferase-assisted quantification of E. coli ultrasonic disruption is convenient, robust, and efficient.

Key words: luciferase, ultrasonic disruption, Escherichia coli, quantitative analysis