Expanding the Scope of the Bioluminescence Inhibition Test

Abstract

Abstract. Rapid and economical tests based on the bioluminescence inhibition reaction of genetically engineered strains with an integrated luminescence gene have found practical application in various fields, including toxicology, ecology, and bacteriology. Their diagnostic potential suggests a wider use in determining the bacteriotropic properties of a wide range of substrates and preparations of various origins. In this work, we tested a testing method using the Escherichia coli lum+ indicator strain with an integrated lux-operon to determine the nonspecific antibacterial activity of bacteriophages and a preliminary assessment of the prebiotic properties of the plant substrate, an aqueous extract of oats. As a well-known model, a metabolite preparation was used - a cell-free ultrafiltrate of the culture liquid of lactobacilli of the Lactobacillus plantarum 8P-A3 strain with a pronounced inhibitory activity. It has been established that the reaction of the test culture makes it possible to determine the stimulating or inhibitory effect on bioluminescence, as well as its dose dependence. The change in the luminescence of the indicator strain under the influence of bacteriophages developed similarly, including the transition from luminescence quenching in the initial period of joint exposure to its stimulation later by 24 h. physiological state of the test strain in the first hours of joint exposure followed by luminescence stimulation. It seems rational to consider the indicator strain in the study of plant substrates as a model representative of the microbiota of the gastrointestinal tract of a macroorganism. Thus, the tested version of testing can be recommended for determining the bacteriotropic properties of the studied and similar objects.