Abstract: The invention presents a method for the culturing of mammalian cells. This method involves the use of a bioreactor, which contains a sample of mammalian cells in a culture medium containing large molecules. Positioned inside the bioreactor is a semipermeable membrane which defines a space separated from the bioreactor by the semipermeable membrane. A nutrient medium flows through this separated space and, via virtue of the semipermeable nature of the separating membrane, nutrient pass therethrough into the culture medium, while cellular waste products pass into the separated space. The semipermeable membrane is selected so that the cells and large molecules, such as proteinaceous materials, cannot pass through the membrane, but remain in the bioreactor.

Abstract: A method of inactivating the biological activity of natural or recombinant DNA in a biomass, by adding a percarboxylic acid containing 1 to 3 carbon atoms, one of its salts, an alkali metal peroxide, or an alkali metal peroxomonosulfate and subsequently heating the mixture to 60.degree. to 100.degree. C.

Abstract: A process for culturing biological material capable of multiplication, especially cells securely adhering to microcarriers, employs a bioreactor having a vessel for a culture medium having means for controlling the environmental conditions in the culture medium and a stirring device for the homogeneous distribution of the cells in the culture medium which has a rotary drive and a rotation axle running in the interior of the vessel, wherein the stirring device has at least one flat stirrer blade fixed on to the rotation axle and inclined to the rotation axle.

Abstract: The present invention teaches restriction endonuclease Asp 718 which cleaves DNA in the palindromic recognition sequence at the sites indicated by the arrow: ##STR1## The endonuclease, obtained from Achromobacter species 718, DSM 2969, is useful in obtaining DNA fragments, e.g., for determining nucleotide sequences and other types of analysis of DNA.

Abstract: A thermostable glycerokinase enzyme useful in the detection and estimation of glycerol derivatives has a half-life in excess of 1 hour at 55.degree. C. at a protein concentration of less than 2 mg/ml and a pH of 7.8 .+-.0.5 in the absence of any substrate. The enzyme is produced by culturing at least one micro-organism which is capable of growth at a temperature of at least 50.degree. C. in a culture medium in which it will produce said enzyme, disrupting the resulting cells of the micro-organism to release the enzyme and separating the enzyme from the cell debris. The medium normally contains at least 0.1% glycerol but certain strains of micro-organism have been found to be capable of producing thermostable glycerokinase enzyme even in the absence of glycerol. The micro-organism is preferably a Bacillus organism, especially of the stearothermophilus species.

Abstract: Glycerol dehydrogenase enzymes having exeptionally good thermal stability are produced by culturing novel strains of Bacillus stearothermophilus. Procedures for deriving and identifying suitable strains are described. The strains are grown in conventional culture media, preferably containing 0.05 to 4.0%, especially 0.1 to 1.0%, by weight of glycerol or a glycerol analogue at 40.degree.-65.degree. C. and pH 5 to 8. The enzyme is isolated by conventional cell disruption and separation techniques, and typically has a molcular weight of 240,000.+-.30,000, composed of four similar sub-units, and a specific activity of greater than 5 Units per mg protein at 30.degree. C. by the modified assay described. They may be stored as aqueous solutions or a freeze dried solids.The enzymes may be used for assay of serum triglycerides by conventional assay methods, but preferably by the nictotinamide adenine dinucleotide spectrophotometric assay at a pH of 7 to 8.8.