Everything on our planet is subject to microbial attacks: living (humans, animals, plants, etc.) and non-living organisms (architectural works, public buildings, artworks). Because of the pressing need for new therapies to treat the bacteria and fungi infections, scientists have directed their studies toward the discovery of natural substances with greater efficacy and lower toxicity, in particular Essential Oils. Essential oils are complex mixtures of volatile compounds, produced naturally in different plant organs during secondary metabolism. Essential oils have great potential as antimicrobial agents due to the presence of various aldehydes, phenolic compounds and terpenes that are active towards a wide range of pathogens. Since 2012, several Italian research projects have been carrying out to better know the antimicrobial activity of essential oils of two aromatic and ornamental species belonging to Monarda genus (Lamiaceae family): Monarda didyma and Monarda fistulosa. To investigate their biological properties, the two species were grown for consecutive years in Imola (Bologna) for essential oils distillation, composition analysis, and antimicrobial activity. Antimicrobial activity was tested on pathogenic and non-pathogenic strains of fungi and bacteria such as Erwinia amylovora, Pseudomonas syringae pv. actinidiae, Staphylococcus aureus, Enterococcus faecalis and Escherichia coli. Major essential oil compounds varied from 11 for Monarda fistulosa to 12 for Monarda didyma. As a general results, a certain increase of thymol, the main component, can be obtained from the second year of cultivation with yield in Monarda didyma twice as high as in Monarda fistulosa. Limonene was only detected in Monarda didyma. Human, animal, and phytopathogenic microorganisms were more sensitive to the antimicrobial properties than the non-pathogenic ones. From the microbiological viewpoint, the study demonstrates that the essential oils from Monarda didyma and Monarda fistulosa, despite compositional differences, share a good potential as antimicrobial agents to be used in the development of biofungicides and biobactericides. Thymol is the most important compound, but not the only one. In fact, the overall antimicrobial activity of essential oils cannot be associated with a single component
Maria Grazia Bellardi, Paola Mattarelli (2021). ESSENTIAL OILS FROM MONARDA spp. AS ANTIMICROBIALS.
ESSENTIAL OILS FROM MONARDA spp. AS ANTIMICROBIALS
Maria Grazia Bellardi
;Paola Mattarelli
2021
Abstract
Everything on our planet is subject to microbial attacks: living (humans, animals, plants, etc.) and non-living organisms (architectural works, public buildings, artworks). Because of the pressing need for new therapies to treat the bacteria and fungi infections, scientists have directed their studies toward the discovery of natural substances with greater efficacy and lower toxicity, in particular Essential Oils. Essential oils are complex mixtures of volatile compounds, produced naturally in different plant organs during secondary metabolism. Essential oils have great potential as antimicrobial agents due to the presence of various aldehydes, phenolic compounds and terpenes that are active towards a wide range of pathogens. Since 2012, several Italian research projects have been carrying out to better know the antimicrobial activity of essential oils of two aromatic and ornamental species belonging to Monarda genus (Lamiaceae family): Monarda didyma and Monarda fistulosa. To investigate their biological properties, the two species were grown for consecutive years in Imola (Bologna) for essential oils distillation, composition analysis, and antimicrobial activity. Antimicrobial activity was tested on pathogenic and non-pathogenic strains of fungi and bacteria such as Erwinia amylovora, Pseudomonas syringae pv. actinidiae, Staphylococcus aureus, Enterococcus faecalis and Escherichia coli. Major essential oil compounds varied from 11 for Monarda fistulosa to 12 for Monarda didyma. As a general results, a certain increase of thymol, the main component, can be obtained from the second year of cultivation with yield in Monarda didyma twice as high as in Monarda fistulosa. Limonene was only detected in Monarda didyma. Human, animal, and phytopathogenic microorganisms were more sensitive to the antimicrobial properties than the non-pathogenic ones. From the microbiological viewpoint, the study demonstrates that the essential oils from Monarda didyma and Monarda fistulosa, despite compositional differences, share a good potential as antimicrobial agents to be used in the development of biofungicides and biobactericides. Thymol is the most important compound, but not the only one. In fact, the overall antimicrobial activity of essential oils cannot be associated with a single componentI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
