Biochemical studies on the Natamycin antibiotic produced by Streptomyces lydicus: Fermentation, extraction and biological activities

Natamycin “polyene” antibiotic was isolated from the fermentation broth of a Streptomyces strain No. AZ-55. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain AZ-55 was identified as Streptomyces lydicus. It is active in vitro against some microbial pathogens viz: Staphylococcus aureus, NCTC 7447; Bacillus subtilis, NCTC 1040; Bacillus pumilus, NCTC 8214 ; Micrococcus luteus, ATCC 9341; Escherichia coli, NCTC 10416; Klebsiella pneumonia, NCIMB 9111; Salmonella typhi and Pseudomonas aeruginosa, ATCC 10145; S. cerevisiae, ATCC 9763; Candida albicans, IMRU 3669; Aspergillus flavus, IMI 111023; Aspergillus niger, IMI 31276; Aspergillus fumigatus, ATCC 16424; Fusarium oxysporum; Alternaria alternata and Rhizoctonia solani. The active metabolite was extracted using chloroform (1:1, v/v) at pH 7.0. The separation of the active ingredient of the antifungal agent and its purification were performed using both thin layer chromatography (TLC) and column chromatography (CC) techniques. The physico-chemical characteristics of the purified antibiotic viz. color, melting point, solubility, elemental analysis (C, H, N, O and S) and spectroscopic characteristics (UV absorbance and IR, mass & NMR spectra) have been investigated. This analysis indicates a suggested empirical formula of C33H47NO13. The chemical structural analysis with spectroscopic characteristics confirmed that the compound produced by S. lydicus, AZ-55 is Natamycin “polyene” antibiotic

Comparative DNA profiling, botanical identification and biological evaluation of Gazania longiscapa DC and Gazania rigens L.

Gazania longiscapa DC and Gazania rigens L. are species of cultivated ornamental plant that grow in Egypt. Genus Gazania has a role in folk medicine to prevent toothache; this study presents a comparative investigation of genetic and botanical features of root, rhizome, leaves and flowers of the two Gazania species and comparing their biological activity as analgesic and antiinflammatory as related to their folk medicinal use. The genetic and botanical differences between the two Gazania species are reported for the first time in this study. The results contribute toward validation of the traditional use of Gazania showing that both species are safe for oral administration and they exhibit significant antinociceptive and anti-inflammatory effects in a dose dependent manner