the streptomycetes are gram positive bacteria with a filamentous form that present in a wide variety of soil including composts, water and plants. the most characteristic of streptomycetes is the ability to produce secondary metabolites such as antibiotics. they produce over two-thirds of the clinically useful antibiotics of natural origin (e.g., neomycin and chloramphenicol. another characteri...

A number of new substituted 1,2,4-triazole, 1,2,4-triazolo[3,4-b]1,3,4-thiadiazole and 1,2,4-triazolo[3,4-b]1,3,4-thiadiazine derivatives were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). The synthesized compounds displayed different degrees of antimicrobial ac...

A strain of Streptomyces griseofuscus S42227 (FERM P-8443) was found to produce new antitumor antibiotics, called azinomycins A and B. The molecular formulas of azinomycins A and B were determined as C30H33N3O10 and C31H33N3O11, respectively. They were active against Gram-positive bacteria, Gram-negative bacteria and L5178Y cells in tissue culture.

A number of new substituted 1,2,4-triazole {[(1,2,4-triazolyl)ethyl]tetrazolyl} derivatives, their sugar hydrazones, and their acyclic C-nucleoside analogues were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). The synthesized compounds displayed different degrees...

A new antibiotic, okicenone was isolated from the culture broth of Streptomyces sp. KO-3599. The antibiotic possesses cytocidal activity against mammalian tumor cells in vitro at concentrations of 0.53-11.0 micrograms/ml whereas the antibiotic showed no antimicrobial activities against Gram-positive and Gram-negative bacteria, fungi or yeast at a concentration of 1,000 micrograms/ml.

A novel aminoglycoside antibiotic, boholmycin, was produced by Streptomyces hygroscopicus H617-25 isolated from a soil sample collected in Bohol Island, the Philippines. It has a pseudotetrasaccharide structure composed of a heptose, two aminosugars and dicarbamoyl-scyllo-inositol. Intrinsic antibacterial activity of boholmycin is weak but it exhibits broad spectrum activity against Gram-positi...

U-56,407, a bright yellow, crystalline antibiotic was isolated from fermentations of Streptomyces hagronensis (strain 360). This antibiotic was extracted from fermentation broths with halogenated hydrocarbons and purified by silica gel chromatography and crystallization. U-56,407 is active in vitro against Gram-positive bacteria but not Gram-negative organisms. It failed to demonstrate in vivo ...

Marine actinomycetes were isolated from the sediments collected from Coromandel Coast region, India. The strain designated as BI244 was found to be an efficient pigment (dark brown-black) producer and has been selected for further studies. The organism was identified as Streptomyces sp. based on morphological, biochemical and physiological characterization. Phylogenetic tree constructed for 16s...

Streptomyces are Gram-positive bacteria that occupy diverse ecological niches including host-associations with animals and plants. Members of this genus are known for their overwhelming repertoire of natural products, which has been exploited for almost a century as a source of medicines and agrochemicals. Notwithstanding intense scientific and commercial interest in Streptomyces natural produc...