Medicinal Plants and Their Bacterial Microbiota: A Review on Antimicrobial Compounds Production for Plant and Human Health

Abstract

Medicinal plants (MPs) have been used since antiquity in traditional and popular medicine, and they represent a very important source of bioactive molecules, including antibiotic, antiviral, and antifungal molecules. Such compounds are often of plant origin, but in some cases, an origin or a modification from plant microbiota has been shown. Actually, the research continues to report the production of bioactive molecules by plants, but the role of plant–endophytic interaction is emerging. Classic examples are mainly concerned with fungal endophytes; however, it has been recently shown that bacterial endophytes can also play an important role in influencing the plant metabolism related to the synthesis of bioactive compounds. In spite of this, a deep investigation on the power of MP bacterial endophytes is lacking. Here, an overview of the studies on MP bacterial microbiota and its role in the production of plant antimicrobial compounds contributing to prime host defense system and representing a huge resource for biotech and therapeutic applications is provided.

Beneficial Relationships Between Endophytic Bacteria and Medicinal Plants

“…Furthermore, the endophytic associations were studied only in approximately 1-2% of the known plant species (Khare et al, 2018), most of which were the land plants, leaving aquatic plants in lakes, ocean, etc., completely untouched. In situ similis culturing and isolation strategy in different plant niches can be used for find more endophytic bacteria (Castronovo et al, 2021).…”

Genomic Analysis of Endophytic Bacillus-Related Strains Isolated from the Medicinal Plant Origanum vulgare L. Revealed the Presence of Metabolic Pathways Involved in the Biosynthesis of Bioactive Compounds

“…The rapid development of multidrug-resistant pathogens requires novel therapeutic chemical compounds, of which medicinal and aromatic plants represent a great reservoir. The discovery that microorganisms residing inside the plant tissues may produce similar, if not the same, bioactive compounds as their plant hosts could offer a new sustainable and promising source of bioactive molecules [ 1 , 2 ].…”

Genomic and Metabolomic Insights into Secondary Metabolites of the Novel Bacillus halotolerans Hil4, an Endophyte with Promising Antagonistic Activity against Gray Mold and Plant Growth Promoting Potential

“…Endophytes live inside plant tissues without causing disease and some can efficiently colonize the rhizosphere as well, while plant growth promoting endophytic bacteria are termed as PGPEB [4]. Medicinal plants seem to harbor endophytes with special characteristics and enhanced antagonistic activity against pathogens [5,6].…”