enhancement of tylosin production in streptomyces fradiae by mutation

The mycarose-biosynthetic genes of Streptomyces fradiae, producer of tylosin.

The tylCK region of the Streptomyces fradiae genome was sequenced, revealing an incomplete set of five tylC genes encoding all-but-one of the enzymes involved in the biosynthesis of mycarose. The latter is a 6-deoxyhexose sugar required during production of the macrolide antibiotic, tylosin. The missing mycarose-biosynthetic gene, tylCVI, was found about 50 kb distant from its functional partne...

The Production of Neomycin by Streptomyces Fradiae

Of basic importance to the study of antibiotic production by microorganisms is a chemically defined medium in which the effect of various nutrients, both organic and inorganic, can be studied with a minimum of interference from ill-defined substances. Such a medium is reported here for the production of neomycin by Streptomyces fradiae, together with studies on the influence of various nitrogen...

Metabolic regulation in tylosin-producing Streptomyces fradiae: phosphate control of tylosin biosynthesis.

The effects of increased concentration of inorganic phosphate on the biosynthesis of tylosin, the level of the intracellular adenylates, the energy charge, and the activities of enzymes involved in the synthesis of tylonolide precursors were studied in Streptomyces fradiae NRRL 2702. No metabolic response was observed when elevated levels of inorganic phosphate were added in idiophase. Increase...

The tylosin producer, Streptomyces fradiae, contains a second valine dehydrogenase.

A second NAD-dependent valine dehydrogenase (VDH) of Streptomyces fradiae was detected and purified to homogeneity by affinity chromatography on Reactive-Blue 2 Sepharose followed by gel filtration and Mono Q fast protein liquid chromatography. The relative molecular masses of the native enzyme and its subunits were determined to be 80,000 and 41,000, respectively, indicating that the enzyme is...

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

Phenotypic changes associated with loss of expression of tylosin biosynthesis and resistance genes in Streptomyces fradiae.

Two mutants of the tylosin-producing Streptomyces fradiae defective in the biosynthesis of the macrolide antibiotic tylosin were isolated from colonies derived from regenerated protoplasts. Both strains were unable to carry out any of at least seven tylosin biosynthetic steps and were sensitive to tylosin. One strain, JS82, was also more sensitive to chloramphenicol (Cm), mitomycin C (Mc), hygr...