Bioprospecting for microorganisms of biotechnological importance in soils contaminated with agrochemicals

The aim of the present study was to isolate microorganisms from soils contaminated with agrochemicals and to evaluate their potential for biodegradation and production of bioactive metabolites. For this, microorganisms were isolated from a soil sample by the serial dilution technique using four different media: potato dextrose agar (PDA), Mueller Hinton agar (MH), malt extract agar (MEA), and Bushnell Haas agar (BH). The isolated microorganisms were identified by their macro and micromorphological characteristics and were tested for their ability to use the DMA 806 BR agrochemical, by the dichlorophenol indophenol (DCPIP) method. Biosurfactant production and antimicrobial activity were evaluated in the selected microorganisms. The emulsifying activity was evaluated by the emulsification index (IE24) technique, while the antimicrobial activity was evaluated through the solid medium assay against pathogens of clinical interest. Among the media tested, MEA yielded the highest number of isolates, as well as a greater diversity of microbial groups, with a predominance of bacteria. Of the selected microorganisms, ten had the ability to use the agrochemical. Of these ten microorganisms, five presented emulsifying activity and two presented the capacity to produce secondary metabolites. Among them, the J5 and B48 strains were distinguished by their emulsifying and antimicrobial activity

New insights into the antimicrobial action of cinnamaldehyde towards escherichia coli and its effects on intestinal colonization of mice

Escherichia coli is responsible for cases of diarrhea around the world, and some studies have shown the benefits of cinnamaldehyde in the treatment of bacterial disease. Therefore, the objective of this study was to evaluate the effects of cinnamaldehyde in mice colonized by pathogenic E. coli, as well as to provide more insights into its antimicrobial action mechanism. After determination of minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations, the interference of cinnamaldehyde in macromolecular pathways (synthesis of DNA, RNA, protein, and cell wall) was measured by incorporation of radioisotopes. The anti-adhesive properties of cinnamaldehyde towards E. coli 042 were evaluated using human epithelial type 2 (HEp-2) cells. Intestinal colonization was tested on mice, and the effect of cinnamaldehyde on Tenebrio molitor larvae. Cinnamaldehyde showed MIC and MBC values of 780 μg/mL and 1560 μg/mL, respectively; reduced the adhesion of E. coli 042 on HEp-2 cells; and affected all the synthetic pathways evaluated, suggesting that compost impairs the membrane/cell wall structure leading bacteria to total collapse. No effect on the expression of genes related to the SOS pathway (sulA and dinB1) was observed. The compound did not interfere with cell viability and was not toxic against T. molitor larvae. In addition, cinnamaldehyde-treated mice exhibited lower levels of colonization by E. coli 042 than the untreated group. Therefore, the results show that cinnamaldehyde is effective in treating the pathogenic E. coli strain 042 and confirm it as a promising lead molecule for the development of antimicrobial agents