Purification and structure elucidation of three naturally bioactive molecules from the new terrestrial Streptomyces sp. TN17 strain.

Thirty litres of fermentation broth was extracted from the newly isolated Streptomyces sp. strain TN17 and various separation and purification steps led to the isolation of three pure bioactive compounds (1-3). Compound 1: cyclo (L-Leu-L-Arg), a diketopiperazine 'DKP' derivative; 2: di-(2-ethylhexyl) phthalate, a phthalate derivative; and 3: cyclo 1-[2-(cyclopentanecarbonyl-3-phenyl-propionyl]-pyrrolidine-2-carboxylic acid (1-carbamoyl-propyl)-amide, a cyclic tetrapeptide derivative.

Bioactive secondary metabolites from a new terrestrial Streptomyces sp. TN262.

During our search for Streptomyces spp. as new producers of bioactive secondary metabolites, the ethyl acetate extract of the new terrestrial Streptomyces isolate TN262 delivered eight antimicrobially active compounds. They were identified as 1-acetyl-beta-carboline (1), tryptophol (2), cineromycin B (3), 2,3-dihydrocineromycin B (4), cyclo-(tyrosylprolyl) (5), 3-(hydroxyacetyl)-indole (6), brevianamide F (7), and cis-cyclo-(L-prolyl-L-leucyl) (8).

The antifungal activity of the terrestrial Streptomyces US80 strain is induced by heat-killed fungi.

Study of the influence of different concentrations of glucose, as carbon source, and magnesium, as chemical additive, on production by the Streptomyces sp. US80 strain of the three antifungal molecules (irumamycin, X-14952 B and 17-hydroxy-venturicidin A) showed that the highest antifungal activity was obtained at 5 g/L and 3.5 mM for glucose and magnesium, respectively.

Purification and structure elucidation of antifungal and antibacterial activities of newly isolated Streptomyces sp. strain US80.

A new actinomycete strain, designated US80 and producing antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi, was isolated from Tunisian oasis soil. Cultural characteristic studies strongly suggested that this strain belongs to the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene (1517 pb) of Streptomyces sp.