THE JOURNAL OF ANTIBIOTICS MECHANISM OF NITROGEN REGULATION OF PROTYLONOLIDE BIOSYNTHESIS IN STREPTOMYCES FRADIAEt

Ammonium ions suppress the amino acid metabolism involved in the biosynthesis of protylonolide in a mutant of Streptomyces fradiae.

Protylonolide is a lactonic precursor of tylosin aglycone, produced by a mutant of Streptomyces fradiae. It originates from n-butyrate, propionate and acetate units. Studies were carried out using a protylonolide-producing mutant on the correlation between protylonolide biosynthesis, regulation by NH4+ and amino acid metabolism. Protylonolide production decreased in a defined medium containing ...

Chimeramycins: new macrolide antibiotics produced by hybrid biosynthesis.

Sir: Microbial conversion of antibiotically inactive macrocyclic lactones to active compounds is an important approach in the search for new macrolide antibiotics. Mutational biosynthesis originally proposed by SHIER et al.1) was proved useful also for constructing new macrolide antibiotics and many new derivatives were obtained. However, these were virtually inactive,2-1) or weakly active and ...

Production of mycarosyl protylonolide by a mycaminose idiotroph from the tylosin-producing strain Streptomyces fradiae KA-427.

Hybrid biosynthesis of derivatives of protylonolide and M-4365 by macrolide-producing microorganisms.

Biotransformation of a macrolide antibiotic and a related compound was studied using various macrolide-producing microorganisms grown in the presence of cerulenin, an inhibitor of de novo synthesis of the aglycone moiety. Protylonolide (1) was transformed into 5-O-(4'-O-propionylmycarosyl)protylonolide (2) by a leucomycin-producing strain, Streptoverticillium kitasatoensis KA-429. M-4365 G2 (3)...

Production of gold nanoparticles by Streptomyces djakartensis isolate B-5

Objective(s):  Biosynthesis of gold nanoparticles (NGPs) is environmentally safer than chemical and physical procedures. This method requires no use of toxic solvents and synthesis of dangerous products and is environmentally safe. In this study, we report the biosynthesis of NGPs using Streptomyces djakartensis isolate B-5.   Materials and Methods: NGPs were biosynthesized by reducing aqueous ...