Occurrence of Streptomyces tauricus in mangrove soil of Mangalore region in Dakshina Kannada as a source for antimicrobial peptide

Optimization and characterization of bioactive secondary metabolites from Streptomyces sp CMSTAAHL-4 isolated from mangrove sediment

BACKGROUND

Ten morphologically different actinomycetes were isolated from mangrove sediments of Manakudy, Kanyakumari District, India. The potent strain was selected based on their primary screening against Gram positive Staphylococcus aureus, Enterococcus faecalis and Gram negative Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi bacterial pathogens. The selected strain was identified as Streptomyces sp CMSTAAHL-4 by 16S rRNA sequencing. The media optimization for secondary metabolites production was performed by One-Variable at a Time and Response Surface Methodology-Central Composite Design. Minimum inhibitory concentration and minimum bacterial concentration for the extracted secondary metabolites were determined. The antioxidant potential of the secondary metabolites showed that the concentration of the metabolites increases, with the percentage of inhibition. The anti-inflammatory activity of the secondary metabolites found that maximum activity was observed at 500 µg/ml of the metabolites. Alcohols, alkenes, alkynes, alkyl halides, carboxylic acids, aliphatic esters functional groups were identified by fourier transform infrared spectroscopy, gas chromatography and mass spectrometer analysis of the secondary metabolites revealed five bioactive compounds. The X-ray diffraction analysis revealed that the secondary metabolites are amorphous. The thermogravimetric analysis showed the thermal stability of secondary metabolites. Atomic force microscopy analysis revealed specific structural characteristics of the secondary metabolites, which may be associated with their potential biological activities.

CONCLUSIONS

The results showed that the antibacterial, antioxidant, and anti-inflammatory chemicals present in the isolated secondary metabolites give them therapeutic properties.

Exploration of bioactive compounds from Olea dioica in Western Ghats of Karnataka using GC-MS

Bioactive compounds in plants are essential for the formation of novel chemotherapeutic drugs, which have been used in Ayurveda to treat a variety of illnesses. Indian medicinal herbs have been used for thousands of years to treat a variety of illnesses, such as fever, cancer, snake bites, rheumatism, skin problems, and neurodegenerative diseases. GC-MS was used to locate and categorize bioactive components in Olea dioica leaves. The results showed that presence of octanoic acid, methyl ester, decanoic acid, methyl ester, desulphosinigrin, l-gala-l-ido-octose, methyl tetradecanoate, Tetradecanoic acid, 6-benzoxazolesulfonamide, N-(2-hydroxyethyl)-2-methyl-, 10-chloro-5-methoxy-5H-dibenzo[a,d][7]annulene, pentadecanoic acid, oleic acid, n-hexadecanoic acid, hexanedioic acid, dioctyl ester, and squalene. The methanol extract of Olea dioica was effective against a wide spectrum of pathogenic bacteria at four different concentrations, with the highest activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Xanthomonas campestris, and Salmonella typhimurium. It also showed moderate activity against Agrobacterium tumefaciens, Pseudomonas aeruginosa, Streptomyces pneumonia, and Pseudomonas syringae. The pharmacological properties of O. dioica, as well as their variety and comprehensive phytochemistry, could be exploited as a potent antimicrobial agent for future therapeutics.

Promising bioactive metabolites of mangrove inhabitant Streptomyces tauricus and prostate cancer PC3 cell inhibition by antimicrobial peptides

Streptomyces is a group of microbes known for antibiotic production and has contributed to more than 70% of present commercially available antibiotics. These antibiotics are important in the management, protection, and treatment of chronic illnesses. In the present study, the isolated S. tauricus strain from mangrove soil in Mangalore, India (GenBank accession number: MW785875) was subjected for differential cultural characterization, phenotype involving brown pigmentation, filamentous mycelia, and ash-colored spore production was observed using field emission scanning electron microscopy (FESEM) analysis revealing filamentous mycelia possessing a straight spore chain. Spores were visualized as elongated, rod-shaped, smooth surfaces with curved edges. After optimized growth conditions for S. tauricus on starch-casein agar medium, the GC/MS analysis of S. tauricus intracellular extract detected bioactive compounds reported for pharmacological applications. Analyzed using the NIST library, most of the bioactive compounds identified in intracellular extract had molecular weights of less than 1 kDa. On the PC3 cell line, the Sephadex G-10 partially purified eluted peak protein fraction demonstrated significant anticancer activity. The LCMS analysis revealed the presence of Tryprostatin B, Fumonisin B1, Microcystin LR, and Surfactin C with molecular weights below 1 kDa. This study found that small molecular weight microbial compounds are more effective in a variety of biological applications.

Antiproliferative activity of antimicrobial peptides and bioactive compounds from the mangrove Glutamicibacter mysorens

The Glutamicibacter group of microbes is known for antibiotic and enzyme production. Antibiotics and enzymes produced by them are important in the control, protection, and treatment of chronic human diseases. In this study, the Glutamicibacter mysorens (G. mysorens) strain MW647910.1 was isolated from mangrove soil in the Mangalore region of India. After optimization of growth conditions for G. mysorens on starch casein agar media, the micromorphology of G. mysorens was found to be spirally coiled spore chain, each spore visualized as an elongated cylindrical hairy appearance with curved edges visualized through Field Emission Scanning Electron Microscopy (FESEM) analysis. The culture phenotype with filamentous mycelia, brown pigmentation, and ash-colored spore production was observed. The intracellular extract of G. mysorens characterized through GCMS analysis detected bioactive compounds reported for pharmacological applications. The majority of bioactive compounds identified in intracellular extract when compared to the NIST library revealed molecular weight ranging below 1kgmole^-1. The Sephadex G-10 could result in 10.66 fold purification and eluted peak protein fraction showed significant anticancer activity on the prostate cancer cell line. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis revealed Kinetin-9-ribose and Embinin with a molecular weight below 1 kDa. This study showed small molecular weight bioactive compounds produced from microbial origin possess dual roles, acting as antimicrobial peptides (AMPs) and anticancer peptides (ACPs). Hence, the bioactive compounds produced from microbial origin are a promising source of future therapeutics.