Soil-Associated Bacillus Species: A Reservoir of Bioactive Compounds with Potential Therapeutic Activity against Human Pathogens

• Published in: Microorganisms (Basel) 2021-05, Vol.9 (6), p.1131
• Main Authors: Yahya, Galal, Ebada, Asmaa, Khalaf, Eman M, Mansour, Basem, Nouh, Nehal A, Mosbah, Rasha A, Saber, Sameh, Moustafa, Mahmoud, Negm, Sally, El-Sokkary, Mohamed M A, El-Baz, Ahmed M
• Format: Article
• Language: English
• Subjects: Antibiotics; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Bacillus; Bacillus subtilis; Bacteria; Bioactive compounds; Biocompatibility; Biological activity; Chemical activity; Chemical compounds; Drug resistance; Glycopeptides; In vivo methods and tests; Keratitis; Methicillin; Microorganisms; MRSA; Multidrug resistant organisms; Nosocomial infections; Nutrients; Pathogens; Pharmacology; Phylogeny; Ribosomal DNA; rRNA 16S; Salts; Soil bacteria; Soil testing; Soils; Staphylococcus aureus; Staphylococcus infections
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms9061131

Soil hosts myriads of living organisms with the extensive potential to produce bioactive compounds. Bacteria are the major soil inhabitants that represent a rich reservoir for antibiotic production along with their role in recycling nutrients and maintenance of the soil ecosystem. Here, from 55 tested soil samples, we isolated and identified a novel antibiotic-producing bacterial strain with a phylogenetically closest match to sp. based on BLASTN search of GenBank for the 16S rRNA gene sequence. We characterized this novel strain through microscopic, biochemical, and molecular techniques, combined with testing its potential antimicrobial activity. Chemical studies revealed that the antibiotic produced by this strain is a glycopeptide. It exhibited profound activity against both methicillin-resistant (MRSA) and . The antibiotic is optimally produced at 37 °C after 28 h of growth. The biocompatibility of the extracted antibiotic was tested over a wide range of factors including temperature, pH, surfactants, and metal salts. To confirm its therapeutic potential, a sterile solution of the antibiotic was tested in vivo against bacteria-induced keratitis in rats where significant healing activity was recorded. Hence, this soil Bacillus strain may lead to the development of novel antibiotics for the treatment of human pathogens.