Previous work with Pseudomonas aeruginosa showed that catalase activity in biofilms was significantly reduced relative to that in planktonic cells. To better understand biofilm physiology, we examined possible explanations for the differential expression of catalase in cells cultured in these two different conditions. For maximal catalase activity, biofilm cells required significantly more iron...

In situ rabbit hearts were subjected to 15 min of regional myocardial ischemia, and at various time points of reperfusion, antioxidant enzyme activity and mRNA expression were measured in ischemic and nonischemic myocardium. Catalase activity increased significantly in both ischemic and nonischemic myocardium, peaking at 1 h after reperfusion and then gradually returning to the control level. N...

BACKGROUND Catalase is preferentially expressed in bronchiolar and alveolar epithelial cells, and acts as an endogenous antioxidant enzyme in normal lungs. We thus postulated epithelial damage would be associated with a functional deficiency of catalase during the development of lung fibrosis. METHODS The present study evaluates the expression of catalase mRNA and protein in human interstitia...

A psychrotolerant bacterium, strain T-3 (identified as Psychrobacter piscatorii), that exhibited an extraordinarily high catalase activity was isolated from the drain pool of a plant that uses H(2)O(2) as a bleaching agent. Its cell extract exhibited a catalase activity (19,700 U·mg protein(-1)) that was higher than that of Micrococcus luteus used for industrial catalase production. Catalase wa...

In the present study, a sensitive modification of the colorimetric assay for catalase activity is reported. This assay is based on the reaction of undecomposed hydrogen peroxide with ammonium molybdate to give a yellowish color, which has maximum absorbance at 354 nm. Catalase-like activity is calculated from a comparison with the activity of a certified standard enzyme with known unit activity...

Hepatic catalase activity in unanesthetized man has been de termined by measuring the disappearance rate of hydrogen perox ide spectrophotometrically in homogenates from needle biopsy specimens of liver. Ten healthy male prisoners, 59 patients with advanced cancer, and 60 cadavers shortly after death with cancer were studied. There is a wide range of catalase activity in normal human liver. Cat...

The s.c. injection of talc, MgSiO3, into mice results in a de crease of hepatic catalase activity. A transient, but marked rise in catalase activity was observed on the 4th day following talc injection. This rise in activity was manifest primarily in the mitochondrial fraction. A concomitant increased incorporation of radioactive leucine occurred in the microsomal fraction. The relationship bet...

Catalase activity of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 isolated from the human large intestine was studied. The high activity of the enzyme in cell-free extracts of both bacterial strains was determined (1745.21154.67 and 873.1172.23 U×mg protein for D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively). The effect of different tempe...

Catalases are widely used in many scientific areas. A catalase gene (Kat) from Geobacillus sp. CHB1 encoding a monofunctional catalase was cloned and recombinant expressed in Escherichia coli (E. coli), which was the first time to clone and express this type of catalase of genus Geobacillus strains as far as we know. This Kat gene was 1,467 bp in length and encoded a catalase with 488 amino aci...