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R Cruz Camarillo

Publications and source records attributed to R Cruz Camarillo.

6 recordsLinked to original sources
PubMed2004

Chitosanase activity in Bacillus thuringiensis.

The ability to produce extracellular chitosanase (EC 3.2.1.132) was found by plate assays in 18 (23%) out of 77 crystalliferous strains of Bacillus thuringiensis. The best chitosanase producer was selected after the growth chosen in a liquid medium with colloidal chitosan as carbon source. Enzyme production was optimized (a 4-d incubation at 32 degrees C with shaking in a medium of pH 6.5 with 4% colloidal chitosan) and the enzyme was partially characterized. This is the first report on the chitosanase of B. thuringiensis.

Bacillus thuringiensis↗
PubMed2004

Colloidal chitin stained with Remazol Brilliant Blue R, a useful substrate to select chitinolytic microorganisms and to evaluate chitinases.

A simple and sensitive method based on the use of colloidal chitin stained with Remazol Brilliant Blue R (RBB) is proposed to evaluate chitinase activity. If this colloidal-stained substrate is included as a carbon source in a liquid medium, this technique allows the selection or the comparison of chitinolytic microorganisms. The colloidal substrate is proportionally solubilized and the dye released is spectrophotometrically quantified at 595 nm. The procedures used for the staining and fixing of RBB in the colloidal chitin, and a comparison with the commercial substrate chitin-azure, are presented. The influence of several physicochemical and enzymatic parameters on the release of dyes is also shown. Both stained substrates were used for studying the effect of pH, substrate concentration, temperature and time on the chitinase reaction of Bacillus thuringiensis Bt-107.

Anthraquinones↗
PubMed1983

Studies on the regulation of X-prolyl dipeptidyl aminopeptidase activity.

The specific activity of X-prolyl-dipeptidyl aminopeptidase in Saccharomyces cerevisiae grown on glucose-containing medium remains constant during exponential growth and increases less than twofold when cells reach the stationary phase. In cells harvested from exponential growth on glucose-containing medium the specific activity of the enzyme is found to be 20-30% lower than the specific activity observed in media without glucose, containing acetate or ethanol as the carbon source. X-Prolyl-dipeptidyl aminopeptidase is not inactivated after the addition of glucose to stationary phase cells. Growth of the yeast on poor nitrogen sources or under nitrogen-starvation results in a three- to fourfold increase in the level of the enzyme.

Dipeptidyl Peptidase 4↗