ABSTRACT
A bacterial strain able to degrade various sulfated galactans (carrageenans and agar) was isolated from the marine red alga Delesseria sanguinea. From the cell-free supernatant of cultures grown on crude lambda-carrageenan, a kappa-carrageenase was purified by ammonium sulfate fractionation, gel filtration on Sephacryl S 200 HR and ion-exchange chromatography on DEAE--Sepharose-CL6B. The purified kappa-carrageenase was detected as a single protein upon SDS/PAGE. Its molecular mass was estimated at 40 kDa. Activity was observed against kappa-carrageenan over the pH range 5.0-8.5 and was optimal at pH 7.2 in Tris buffer or 7.0 in Mops buffer. The enzyme activity remained stable at 30 degrees C, but only for up to 1 h at 40 degrees C. Analysis of the degradation products of the kappa-carrageenase by gel filtration and 13C-NMR spectroscopy indicated that the enzyme degrades kappa-carrageenan down to the level of the kappa-neocarratetraose sulfate. The properties of this new enzyme are compared with those of previously characterized carrageenases.
Subject(s)
Bacterial Proteins , Glycoside Hydrolases/isolation & purification , Rhodophyta/enzymology , Carrageenan/metabolism , Chromatography , Glycoside Hydrolases/metabolism , Hydrolysis , Kinetics , Magnetic Resonance Spectroscopy , Molecular Weight , Substrate SpecificityABSTRACT
Protoplasts were isolated from female gametophytes of Chondrus crispus (Stackh.) using commercial cellulase and various carrageenases prepared from marine bacteria. Depending on the nature of the donor tissue (apices or whole thallus, wild or cultivated strains), yields ranged from 1.0-8.5×10(8) protoplasts per gram of fresh tissue. Preincubating the tissue with a potassium chelator, Kryptofix 222, enhanced protoplast yields by 30-50 %. Based on staining with fluorescein diacetate most protoplasts were viable. A few protoplasts regenerated a cell wall and divided.
ABSTRACT
With reference to 5 personal cases involving the mandible 3 times and the lower gum twice, the authors recall the principal characteristics of calcified odontogenic cysts: very little clinical manifestation frequently limited to simple tumefaction, well bounded radiological image with low density, cyst with an epithelial border comprized of calcification and ghost cells. Calcified odontogenic cysts which have a definite morphological likeness to Malherbe's epithelioma, also have the same benigh course as the latter.
