Rhizospheric Actinomycetes Revealed Antifungal and Plant-Growth-Promoting Activities under Controlled Environment

• Published in: Plants (Basel) Vol. 11; no. 14; p. 1872
• Main Authors: Elshafie, Hazem S, Camele, Ippolito
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.07.2022; MDPI
• Subjects: Actinobacteria; Actinomycetaceae; Actinomycetes; Agriculture; antagonistic activity; Antibiotics; Antimicrobial agents; Antiviral activity; Arthrobacter; Bacteria; Bioactive compounds; bioactive substances; biocontrol; Biological activity; Biological control; Chitinase; Disease control; E coli; Enzymes; Fungi; Fungicides; Gram-positive bacteria; Growth hormones; Marine plants; Marine sediments; Metabolites; microbial biostimulants; Microorganisms; Pectinase; Pharmaceutical industry; Physiology; phytopathogens; Plant bacterial diseases; Plant diseases; Plant growth; Plant roots; Plant species; Rhizosphere; Secondary metabolites; Sediments; Seedlings; Streptomyces; Terrestrial environments; Tomatoes; Actinobacteria; microbial biostimulants; phytopathogens; biocontrol; bioactive substances; antagonistic activity
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants11141872

has large habitats and can be isolated from terrestrial soil, rhizospheres of plant roots, and marine sediments. produce several bioactive secondary metabolites with antibacterial, antifungal, and antiviral properties. In this study, some strains were isolated from the rhizosphere zone of four different plant species: rosemary, acacia, strawberry, and olive. The antagonistic activity of all isolates was screened in vitro against and . Isolates with the strongest bioactivity potential were selected and molecularly identified as sp., , and . The growth-promoting activity of the selected isolates was in vivo evaluated on tomato plants and for disease control against . The results demonstrated that all bacterized plants with the studied isolates were able to promote the tomato seedlings' growth, showing high values of ecophysiological parameters. In particular, the bacterized seedlings with sp. and showed low disease incidence of infection (0.3% and 0.2%, respectively), whereas those bacterized with showed a moderate disease incidence (7.6%) compared with the positive control (36.8%). In addition, the ability of the studied to produce extracellular hydrolytic enzymes was verified. The results showed that was able to produce chitinase, glucanase, and protease, whereas sp. and produced amylase and pectinase at high and moderate levels, respectively. This study highlights the value of the studied isolates in providing bioactive metabolites and extracellular hydrolytic enzymes, indicating their potential application as fungal-biocontrol agents.