Riboflavin analgs from Streptomyces davawensisas antiinfectives: mode of action, mechanism of resistance of the producer and metabolization by humans

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise e expressão de genes de PKS II e de carboidrases provenientes de bibliotecas metagenômicas

Pós-graduação em Microbiologia Agropecuária - FCAV

Keratinolytic activity of Streptomyces sp isolated of poultry processing plant

The keratin is not degraded by common enzyme, keratinases have the ability to degrade native keratin and others insoluble enzymes. In the present work was Studied keratinase produced by Streptomyces sp LMI-1 isolated from industrial plant of poultry processing. The enzyme degraded 87% of feathers after 120 h, it was stimulated by Ba(2+) and inhibited by Ca(2+), Mn(2+), EDTA and Hg(+). The optimum pH and temperature for the enzyme was 8.5 and 60 degrees C, respectively. The enzyme was stable after 2 hours at 50 degrees C. The culture broth analysis by thin layer chromatography showed presence of amino acids serine, methionine, proline, tyrosine and leucine after 72 hours of incubation. The microorganism showed potential for use in industrial process because of higher enzyme production and feathers degradation.

The antibiotics roseoflavin and 8-demethyl-8-amino-riboflavin from Streptomyces davawensis are metabolized by human flavokinase and human FAD synthetase

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Production of clavulanic acid and cephamycin C by Streptomyces clavuligerus under different fed-batch conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of different media for the production of cephalosporins by Streptomyces clavuligerus ATCC 27064

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

INFLUENCE of GLYCEROL and ORNITHINE FEEDING on CLAVULANIC ACID PRODUCTION BY Streptomyces clavuligerus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Optimisation of the glycerol-to-ornithine molar ratio in the feed medium for the continuous production of clavulanic acid by Streptomyces clavuligerus

Amino acids are well metabolized by Streptomyces clavuligerus during the production of clavulanic acid using glycerol as main carbon and energy source. However, only a few amino acids such as arginine and ornithine are favorable for CA biosynthesis. The aim of this work was to optimize the glycerol:ornithine molar ratio in the feed medium containing only these compounds to maximize CA production in continuous cultivation. A minimum number of experiments were performed by means of a simple two-level full-factorial central composite design to investigate the combined effect of glycerol and ornithine feeding on the CA concentration during the intermittent and continuous process in shake-flasks. Statistical analysis of the experimental data using the response surface methodology showed that a glycerol-to-ornithine molar ratio of approximately 40:1 in the feed medium resulted in the highest CA concentration when fermentation was stopped. Under these optimized conditions, in bench-scale fermentor runs, the CA concentration reached more than double the concentration obtained in shake-flasks runs. (C) 2009 Elsevier B.V. All rights reserved.

Assay of Serum Glutamic-Oxaloacetic Transaminase Using Malate Dehydrogenase Preparation Obtained from Streptomyces aureofaciens

A modified spectrophotometric method for serum glutamic-oxaloacetic transaminase (SGOT) assay was developed. A crude cell-free extract from Streptomyces aureofaciens which showed a high level of malate dehydrogenase (MDH) activity (E.C. 1.1.1.37) was used as the enzymatic indicator. The lyophilized microbial preparation was used without previous purification and was quite stable under refrigeration for one year. Serum sample assays using both the method utilizing the crude cell extract and an enzymatic commercial kit showed good correlation.

Clavulanic acid production by immobilized cells if Streptomyces clavuligerus

A clavulanic acid production process with immobilized Streptomyces clavuligerus cells was investigated. Cells were immobilized in diatomaceous earth, calcium alginate gel as well as in the form of natural pellets and cultivated in shake flasks in a medium containing glycerol and soytone as the carbon and nitrogen sources, respectively. In all experiments growth occurred in the first 48 h and glycerol consumption after 72 h, while clavulanic acid production was observed between 48 and 60h, with gradual degradation after this period. The natural pellets presented higher product concentration as compared with the cells immobilized in supports. However, calcium alginate was found to be the best support in relation to cell retention capacity.

Influence of free amino acids on clavulanic acid production by Streptomyces clavuligerus in synthetic medium

The effect of nitrogen source on clavulanic acid production was investigated in shake flasks. Media containing asparagine plus one of several different amino acids or a combination of two amino acids was tested. The best result, ca. 180 mg/L clavulanic acid, CA, in 60 h, was obtained with the lysine-tyrosine pair In an aerated and agitated fermentor this medium led to CA concentrations of ca. 210 mg/L, a remarkable production for synthetic medium utilization. Amino acids analysis during cultivation indicated that, while asparagine was consumed rapidly, lysine and tyrosine were metabolized slowly, promoting CA production.

Fractionation and identification of the nucleic acid-related substances secreted by Streptomyces aureofaciens

S. aureofaciens growth in a chemically defined medium was associated with the active secretion of nucleic acid-related substances in the medium. High secretion depended on low availability of phosphate, and fractionation showed 7 anionic substances were secreted as major components. When compared to 76 known purine and pyrimidine derivatives only erotic acid was identified. Cationic components are among the minor concentration components secreted which have been identified as cytosine, inosine, cytidine, adenine, guanine and, probably, 1-methyl-adenine.