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Biomedical subjects

J Zemek

Publications and source records attributed to J Zemek.

At least 19 recordsLinked to original sources
PubMed1987

Antimicrobial effects of some mono- and bishydrazones.

Antibacterial, antifungal and antiprotozoal effects of nine mono- and bishydrazones of glycolaldehyde, glyoxal, methoxyacetaldehyde and glutaraldehyde were studied using eight model organisms. It was found that bishydrazones are much more efficient antimicrobial agents than monohydrazones in the case of all model microorganisms.

Animals↗
PubMed1987

Antimicrobial properties of aromatic compounds of plant origin.

The antimicrobial action of 11 compounds involving guaiacyl- and syringyl-like structures (low-molecular-weight part of lignin), gallic acid and its derivatives, cinnamic acid and its derivatives, veratric acid, anisic acid and crotonic acid (a total of 25 compounds) against bacteria, yeast-like organisms and protozoa was examined. Aromatic compounds modified in the C-side chain and aldehydes were effective preferentially against Trichomonas vaginalis, whereas against bacteria and yeast-like organisms eugenol was the most effective inhibitor.

Anti-Bacterial Agents↗
PubMed1986

Antiprotozoal effects of some hydrazones.

Antiprotozoal effects of hydrazones derived from compounds with 1 to 4 carbon atoms were studied on the model organism Trichomonas vaginalis isolated from a female patient with acute urogenital trichomoniasis.

Animals↗
PubMed1985

Antimicrobial effect of sugar osazones and anhydro sugars.

The antimicrobial effect of 14 sugar osazones and anhydro sugars was studied with model strains of Micrococcus luteus, Bacillus licheniformis, Escherichia coli and strains Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical material. The relationship between the structure of these compounds, their solubility in water and 1-octanol and antimicrobial effect was investigated.

Bacillus↗
PubMed1982

Determination of the molecular weight of alpha-amylase, as the enzyme-inhibitor complex, using thin layer gel filtration on Sephadex.

Thin layer gel filtration on Sephadex was performed as a simple method for recognition of the small molecular weight differences of human alpha-amylases from different sources. Activity was located with dry chromogenic substrate, using a replica technique. Undesirable interaction between the gel matrix and substrate binding sites on the enzyme, which causes an anomalous decrease in the migration rate of the enzyme protein, was suppressed by preincubation of the enzyme with appropriate inhibitor. Gradual masking of substrate binding sites of the enzyme by increasing concentrations of amylase inhibitors resulted in two distinct migration rates for the enzyme in thin layer gel filtration. This suggests the existence of two substrate binding sites in the enzyme molecule. Together with thin layer gel affinity chromatography on a mixture of Sephadex and ConA-Sepharose, the method yielded useful data on the molecular weight of amylase and its glycosylated forms and served as a valuable tool for the differential diagnosis of macroamylasaemia.

Amylases↗
PubMed1981

Production of beta-glucosidase, exo-beta-1,4-glucanase and endo-beta-1,4-glucanase by selected microscopic fungi.

Production of beta-glucosidase, exo-beta-1,4-glucanase and endo-beta-1,4-glucanase was screened in 58 species of imperfect fungi, mucoral fungi and some ascomycetes. beta-Glucosidase activity was found in all of the tested microorganisms, exo-beta-1,4-glucanase activity in 23, and endo-beta-1,4=glucanase activity in 38 microorganisms. Growth on cellobiose was found in all tested microorganisms, growth on carboxymethylcellulose in in 38 tested strains.

Ascomycota↗
PubMed1981

Production of alpha-amylase by microscopic fungi.

The amylolytic activity and especially the production of alpha-amylase (EC 3.2.1.1) and alpha-glucosidase (EC 3.2.1.20) was screened in imperfect fungi, mucoral fungi and some ascomycetes. The character of the polysaccharide system, which is responsible for the utilization of alpha (1 to 4) glucan, was specified with a concomitant screening of growth on soluble starch. The amylolytic activity was found in 29 strains out of the 49 tested.

Amylases↗
PubMed1981

[beta-1,3-1,4-glucanase in spore-forming microorganisms. IV. Properties of some Bacillus-beta-glucan-hydrolases (author's transl)].

The beta-glucan-hydrolases produced by seven Bacillus species have been characterized with regard to some physicochemical properties. Ca-ions stabilize all tested glucanases. Optimum pH and optimum temperature were found to be different for the investigated enzymes. In the work presented here is given further characteristics of Bacillus-beta-glucan-hydrolases as pH-stability and temperature stability, sensibility on glucono-1,5-lactone, as well known inhibitor of carbohydrases, and electrophoretic mobility on cellulose acetate-sheets.

Bacillus↗
PubMed1980

Biochemical similarities among strains of Aureobasidium pullulans (de Bary) Arnaud.

Seventy-seven properties of Aureobasidium pullulans including utilization of various carbon sources, decomposition of the lignin-cellulose complex and the respective enzymes were checked in the present communication. According to these properties the group of 43 strains was separated in three parts, out of which two groups were found to belong to varieties A. pullulans var. pullulans and A. pullulans var. melanigenum. The third group formed a marginal part. The two varieties differed in numerous biochemical markers, particularly in the absence of monophenol monooxygenase in the variety A. pullulans var. pullulans.

Carbohydrate Metabolism↗
PubMed1980

Mannan-hydrolyzing enzymes of yeasts and yeast-like organism.

The ability to degrade mannan in the yeast Saccharomyces cerevisiae, i.e. the ability to produce an enzyme of the alpha-mannosidase type was tested in 57 representatives of various genera and species of yeasts and yeast-like organisms. Their growth was simultaneously monitored on soluble mannan and on 4-nitrophenyl-alpha-D-mannopyradnoside. The majority of strains produced alpha-mannosidase (EC 3.2.1.24).

Mannans↗
PubMed1980

Cellulase activity of higher fungi.

The method of liquefaction of gel from cross-linked cellulose was used for monitoring the cellulolytic activity of 114 cultures of higher fungi, 47 of which belonged to Pleurotus ostreatus. All cultures of P. ostreatus had a low activity. The highest cellulase activity, manifested by Piptoporus betulinus, was comparable with that of Tricloderma viride QM6a.

Basidiomycota↗