The modern paradigm assumes that interspecies communication of microorganisms occurs through precise regulatory mechanisms. In particular, antagonism between bacteria or bacteria and fungi can be achieved by direct destruction of the targeted cells through the regulated production of antimicrobial metabolites or by controlling their adaptive mechanisms, such as the formation of biofilms. The quorum-quenching phenomenon provides such a countermeasure strategy. This review discusses quorum-sensing suppression by Gram-positive microorganisms, the underlying mechanisms of this process, and its molecular intermediates. The main focus will be on Gram-positive bacteria that have practical applications, such as starter cultures for food fermentation, probiotics, and other microorganisms of biotechnological importance. The possible evolutionary role of quorum-quenching mechanisms during the development of interspecies interactions of bacteria is also considered. In addition, the review provides possible practical applications for these mechanisms, such as the control of pathogens, improving the efficiency of probiotics, and plant protection.

The effect of bacterial strains on certain genera, both independently and in combination with biochar in various options, on petroleum hydrocarbon decomposition in chernozem and the restoration of the ecological state of the soil were studied. To simulate petroleum hydrocarbon contamination, petroleum hydrocarbons were introduced into soil in the amount of 5% of soil weight. Strains of Bacillus and Paenibacillus bacteria (in recommended and increased doses × 100) and biochar (1% of soil weight) were introduced into contaminated soil separately and together. It was found that after 30 days, the oil content decreased with the joint introduction of an increased dose of Bacillus, Panibacillus and biochar by 64%, as well as with the inoculation of biochar with Bacillus and Panibacillus bacteria at the recommended dose by 67%. The introduction of biochar, inoculated with BP and BP × 100, contributed to an increase in the intensity of CO₂ emission compared to the background by 5–10%. With the joint introduction of BP + B, stimulation was 70%, with an increase in the concentration of BP × 100–115%. The preparation BP and BP × 100 introduced with biochar stimulated the activity of the enzyme by 49 and 61%; with the preinoculation of BP in biochar, stimulation was 27% relative to the background value. The most informative biological indicators when introducing ameliorants of biochar, Bacillus and Paenibacillus were the total number of bacteria, the length of the barley roots and the catalase activity, demonstrating the greatest sensitivity. The results of the study should be used for the remediation and biomonitoring of the state of oil-contaminated soils.

Evgeniya Valer’evna Prazdnova, Vladimir Anatolevich Chistyakov, Nikita Gennadjevich Vasilchenko, Radomir Viktorovich Skripnichenko, Alina Yurievna Gulyaeva, Anna Valentinovna Aleshukina, Iraida Sergeievna Berezinskaya, and Dmitriy Vladimirovich Rudoy. Prev Nutr Food Sci 2025;30:274-84. https://doi.org/10.3746/pnf.2025.30.3.274

This study investigates the range of secondary metabolites with antifungal activity produced by bacterial strains that have been previously characterised as antagonistic strains to phytopathogenic fungi. The properties of ten strains were analyzed in silico through functional genomic analysis and in vitro by mass spectrometry. The research has demonstrated that Bacillus and Paenibacillus strains possess diverse gene clusters for biosynthesis of secondary metabolites, including peptides and polyketides. Mass spectrometry analysis confirmed the synthesis of key antimicrobial peptides, such as surfactin, fengycin, macrolactin, and fusaricidin, which are associated with antifungal activity. These strains have been observed to exhibit robust antagonism against phytopathogenic fungi—the diameter of the inhibition zones for the presented strains was at least 20 mm. This feature highlights their potential as biocontrol agents. The presence of numerous uncharacterized gene clusters suggests the possibility of discovering previously undescribed bioactive compounds.

Rapid development of molecular genetic technologies made it possible to analyze in detail the phenomena that can be attributed to epigenetics, i.e., phenotypic switches in bacterial cell cultures. Phenotypic changes against the background of an unchanged genome can be a temporary reaction to external factors and disappear with the change of conditions or can be caused by cell differentiation and maintained regardless of external factors. In the literature, extremely heterogeneous terminology with synonymous terms for these phenomena is used, depending on their characteristics (bistability, specialization, hysteresis, phase variation, dissociation). One of the objectives of this review is to systematize the terminology used. Representatives of the genus Bacillus were selected as an object of analysis, since they exhibit a considerable number of epigenetic phenomena. In addition, bistability is an important factor affecting the efficiency of using bacteria of the genus Bacillus in biotechnological processes. The study provides a brief overview of epigenetic switches in the genus Bacillus, their mechanisms, methods of detection and analysis, and possible evolutionary and ecological role, as well as practical applications.