earticle

영어

Reporter proteins, such as GFP, beta-galactosidase and luciferase, have been used in many studies to monitor biological activities. For researchers working with predatory strains, top agar plates are needed to determine the population numbers, typically requiring 4 days. In this study, therefore, reporter proteins were used to monitor the kinetics of predatory bacterial strains and evaluated as a tool to estimate their numbers in a much shorter time. It was found that the fluorescent proteins, including CFP and RFP, were not degraded by the predatory bacteria but were released into the supernatant after lysis of the prey. As such the “ackground”ú fluorescence increased faster with a higher multiplicity of infection (MOI) ratio but required about 6 hours for determination. In contrast, the bioluminescence, which is integrally related with the energy level of the cell, decreased shortly after mixing the predator and prey, indicative of a reduced metabolic activity from the attacked prey. This decrease was faster for higher MOIs, allowing us to reliably estimate the predator numbers within 1 hour.