Biomedical subjects

F Percheron

Publications and source records attributed to F Percheron.

At least 55 records · Page 3Linked to original sources

PubMed1976

[Purification of alpha-amylase by affinity chromatography on cross-linked starch].

Affinity chromatography on cross-linked starch affords a simple and rapid procedure for alpha-amylases (EC 3.2.1.1.) purification. When starch is cross-linked in alkaline medium by epichlorhydrin in the conditions described, the insoluble polysaccharide obtained is able to retain specifically the alpha-amylase which is then eluted with 2M maltose solution. alpha-amylase can be obtained in a pure form with a 60% yield. The exoenzyme beta-amylase (EC 3.2.1.2) is not retained by the support and is eluted with other contaminant proteins. Therefore, this procedure allows the separation of the endo- and exoamylase activities.

Amylases↗

PubMed1976

[Isolation and characterization of two strains of Streptomyces able to metabolize natural polysaccharides including mannan (author's transl)].

Two strains of aerobic and mesophilic microorganisms were isolated from palm-tree plantation sand. They grew on insoluble polysaccharides: mannan, cellulose, chitin as only source of carbon. This lytic activity was used for the purification of the two strains. The morphology of the organisms and the presence of LL-diaminopimetic acid in their cell-wall are characteristic of the genus Streptomyces. Investigations lead to: 1) the characterization of their specific polysaccharidase activity toward insoluble and natural beta-and alpha-glycans (mannan, cellulose, chitin, pectine and starch) and the formation of soluble saccharides (mannobiose, cellobiose, beta-D-N-acetylglucosamine, galacturonic acid, and maltose); 2) the research for antagonist, or synergic, effect on pathogenic bacteria and certain phytopathogenic microorganisms; only in the case of these latter was a weak lytic activity exerted by the two Streptomyces isolates, but one of them was shown to stimulate Colletotrichum lindemuthianum and Phialophora cinerescens; 3) a study of antibiotic sensitivity; the two strains were sensitive to tetracycline and streptomycin, but they had native resistance to other aminosides (gentamicin, kanamycin), to erythromycin and to the beta-lactam antibiotics (penicillin and cephalosporin); they possessed a beta-lactamase bound to the cell membrane.

Aerobiosis↗

PubMed1976

[Assimilation of insoluble beta mannan by a strain of Streptomyces from the soil].

A strain of Streptomyces hydrolysing the insoluble beta (1 leads to 4) mannan has been isolated from a soil of palm plantation. The first step in the degradation of the polysaccharide is a random hydrolysis by a beta mannanase, leading to mannotetra-, mannotri- and mannobiose. Liberation of free mannose is never observed. The hydrolysing pattern of oligomannosides and of their reduced homologues has been studied and a transfert reaction is postulated. This mannanase behaves as a true endopolysaccharidase.

Glycoside Hydrolases↗

PubMed1975

[Metabolism of Helix pomatia polygalacturonase].

The reaction pattern of the polygalacturonase from Helix pomatia juice has been studied. Hydrolysis of pectic acid occurs in a random manner. Oligogalacturonic acids are hydrolyzed in a sequential process, starting from the non-reducing end. This behavior is different from that of other endopolygalacturonases, which split these latter substrates both randomly and in a stepwise way from the reducing end.

Animals↗

PubMed1975