Laura Escalante

Learn More
The effect of glucose on growth and anthracycline production by Streptomyces peucetius var. caesius was examined in a chemically defined medium. Glucose concentrations above 100 mM inhibited anthracycline synthesis in the original strain without causing significant change in growth and final pH values. This effect was observed when the carbohydrate was(More)
The effect of a D-glucose on growth and erythromycin production by Streptomyces erythraeus was investigated. D-Glucose stimulated growth and caused a strong but temporary suppression of antibiotic formation. Maximum specific suppression of erythromycin formation occurred at a carbohydrate concentration of 20 mg ml-1. A non-metabolizable analogue of glucose,(More)
A new type-II restriction endonuclease SphI, has been partially purified from Streptomyces phaeochromogenes. SphI recognizes the hexanucleotide sequence 5'-GCATGC and cleaves it at the position marked by the arrow. This nucleotide sequence is present twice in SV40 DNA, four times lambda DNA and only once in the cloning vehicles pBR322, pBR325, pBR327 and(More)
Starch is degraded by amylases that frequently have a modular structure composed of a catalytic domain and at least one non-catalytic domain that is involved in polysaccharide binding. The C-terminal domain from the Lactobacillus amylovorus α-amylase has an unusual architecture composed of five tandem starch-binding domains (SBDs). These domains belong to(More)
Penicillium chrysogenum produced glutathione after growth in a defined medium containing 10 mM-NH4Cl as the sole source of nitrogen. The use of higher ammonium concentrations (100 mM) resulted in stimulation of growth and glutathione formation. In addition, increases in the intracellular pools of glutamate, alanine and glutamine, proportional to the amount(More)
Using an antibiotic enrichment procedure, eight mutants of Streptomyces peucetius var. caesius were isolated for their sensitivity to the glucose analogue 2-deoxyglucose (DOG), from a DOG-resistant strain (Dog(R)). These mutants (Dog(S)) and their parent strain were examined for growth sensitivity to DOG, glucose kinase (Glk) activity, glucose uptake, and(More)
Streptomyces peucetius var. caesius produces a family of secondary metabolites called anthracyclines. Production of these compounds is negatively affected in the presence of glucose, galactose, and lactose, but the greatest effect is observed under conditions of excess glucose. Other carbon sources, such as arabinose or glutamate, show either no effect or(More)
SCO2127 and SCO2126 (glkA) are adjacent regions located in Streptomyces coelicolor DNA. glkA encodes glucose kinase (Glk), which has been implicated in carbon catabolite repression (CCR) in the genus Streptomyces. In this work, the glkA and SCO2127 genes from S. coelicolor were used, either individually or together, to transform three mutants of(More)
The effect of utilizable carbon sources on the production of gentamicin by Micromonospora purpurea has been studied. High D-glucose and D-xylose concentrations (40 mg/ml), exerted a strong and permanent negative action on antibiotic formation. On the other hand, similar concentrations of D-fructose, D-mannose, maltose and starch caused no effect. The(More)
In Streptomyces peucetius var. caesius, the production of anthracyclines was suppressed either by 330 mM d-glucose or 25 mM phosphate. In addition, the anthracycline doxorubicin and the glucose analogue 2-deoxyglucose inhibited the growth of this microorganism at concentrations of 0.025 mM and 10 mM respectively. Spontaneous and induced mutants, resistant(More)