Formation of Indoleacetic Acid by Enterbacteria Pathogenic for Human

Background. At present, the problem of plant colonization by bacteria pathogenic for human is of particular interest. Among the bacteria capable of polyhostality, species of the Enterobacteriaceae family, which includes both phytopathogenic and human pathogens, are of particular interest. Fruits and vegetables contaminated with such pathogens have been shown to be able to cause human intestinal infections. Being one of the ways of communication in the plantmicroorganism system, it is possible that the synthesis of indole acetic acid (IAA) by Enterobacteriaceae determines the growth rate of bacteria, contributing to more rapid colonization of the plant.Aim: comparative study of the synthesis of IAA by different types of enterobacteria.Methods. Eight types of enterobacteria were used in the study, seven of which were isolated from sick people, as well as the phytopathogen Pectobacterium carotovorum spp. carotovorum. The work was performed using microbiological and spectrophotometric research methods.Results. The ability of the synthesis of IAA by opportunistic microorganisms belonging to the Enterobacteriaceae family was studied. We found that the majority of the studied strains synthesize IAA. Studies on the effect on the synthesis of IAA, the introduction into the nutrient medium of tryptophan and its enrichment with glucose, as well as the variation of the temperature regime of the cultivation of bacteria were carried out

The effect of humic substances on test-objects

The complex study of a number of humic substances was conducted with help of bioassay methods using invertebrates (Daphnia, paramecium, earthworms), terrestrial (wheat seeds) and aquatic plants (elodea, duckweed) and algae (Scenedesmus quadricauda). The ranges of concentrations of humates that have a negative and a stimulating effect on biological objects were identified. The efficiency of biological testing methods to evaluate the effect of humic substances on biological objects is shown