STUDY OF ANTIMICROBIAL PROPERTIES OF ESSENTIAL OILS OF EUCALYPTUS, ROSEMARY, JUNIPER, CLOVE, FIR AND BASIL

Abstract

This article focuses on the study of the antimicrobial activity of essential oils from essential oil-bearing plants - round or ball eucalyptus (Eucalyptus globulus), Siberian fir (Abies sibirica), common juniper (Juniperus communis), rosemary (Rosmarinus officinalis), sweet cornflower (basil) (Ocimum basilicum), clove tree (Eugenia Caryophyllus), which have antimicrobial activity against pathogenic and opportunistic microflora. Essential oils (essential oils, volatile oils) are organic volatile compounds with numerous components (more than 200 biologically active substances) consisting of terpenes, alcohols, aldehydes, ketones, and hydrocarbons synthesized by essential oil plants in the course of their life. Essential oils, as promising antibacterial agents of plant origin, can be an alternative to antibiotic drugs, as they are not inferior in terms of antimicrobial effect and at the same time they are free from the negative properties and effects that are characteristic of the vast majority of antibiotics. Museum cultures of opportunistic bacteria were used as test microorganisms in the study: gram-negative Escherichia coli (ATCC 25922), Proteus vulgaris (ATCC 4636), and gram-positive Staphylococcus aureus (ATCC 25923) and Bacillus subtilis (ATCC 6633). Antimicrobial activity was determined by the disc diffusion method. The study was conducted qualitatively, using sterile paper discs impregnated with essential oil. This method has certain differences compared to the antibiotic susceptibility test. Due to the high activity of essential oils to inhibit microflora aerogenously and the possible potentiation or synergy of their action, it is advisable to study each essential oil separately (i.e., only one disc impregnated with the test essential oil is placed in one Petri dish). For control purposes, the same cultures were sown and discs impregnated with saline were placed. All crops were kept in a thermostat for 22-24 hours. The results of the experiments were evaluated by measuring (mm) the colony growth retardation zone (CGR) (including the diameter of the disc itself). By studying the sensitivity of isolated microorganisms to essential oils, it was found that almost all the essential oils studied (juniper, eucalyptus, fir, clove, cornflower, rosemary) have high antimicrobial activity. This is because bactericidal doses of essential oils cause profound morphological, ultural, and biochemical changes in microorganisms, in particular, they lead to changes in antigenic properties, and a decrease or complete loss of pathogenicity. Interacting with proteins of microorganisms, essential oils can inactivate their enzyme systems, inhibiting oxidative phosphorylation, blocking the formation of macroregion bonds, etc.The studied microbiological properties of essential oils indicate a wide range of their antimicrobial effects. In particular, about cultures of opportunistic and pathogenic bacteria, the highest antimicrobial activity is observed in essential oils of common cornflower (Ocimum basilicum) - (E. soli (20.2±0.5), Staph. aureus (27.8±0.7), Bac. subtilis (22.3±0.5), Prot. vulgaris (31.2±0.3) and Eucalyptus globulus (Eucalyptus globulus) - (E. Soli (17.5±0.7), Staph. aureus (22.6±0.4), Bac. subtilis (29.2±0.7), Prot. vulgaris (13.3±0.7).The following essential oils had a less pronounced antimicrobial activity against cultures of gram-positive and gram-negative bacteria: Juniperus communis - (E. soli (13±0.5), Staph. aureus (8.3±0.6), Bac. subtilis (11.5±0.5), Prot. vulgaris (12.5±0.6); Siberian fir (Abies sibirica) (E. Soli (10.2±0.6), Staph. aureus (14.5±0.6), Bac. subtilis (9.6±0.5), Prot. Vulgaris (no growth retardation zone); clove tree (Eugenia Caryophyllus) - E. coli (17.2±0.7), Staph. aureus (14.0±0.7), Bac. subtilis (no growth retardation zone), Prot. Vulgaris (16.0±0.5); rosemary (Rosmarinus officinalis) - (E. soli (23.5±0.5), Staph. aureus (15.3±0.7), Bac. subtilis (no growth retardation zone), Prot. vulgaris (21.5±0.5).