360

ible to assay bilirubin by measuring a decrease in absorption in the visible region of the reaction solution. Thus, it can be used for assaying bi- lirubin and for removing it from a sample to avoid its interference in determining a substrate or an enzyme activity.

4677068

P R O C E S S F O R O B T A I N I N G C H O L E S T E R O L E S T E R A S E

Wolfgang Wania, Jurgen Wahl, Maximilian Kellner, Sindelsdorf, Federal Republic Of Ger- many assigned to Boehringer Mannheim GmbH

The present invention provides a process for ob- taining cholesterol esterase by culturing an ap- propriate micro-organism in an appropriate nutrient medium and recovering the enzyme from the culture broth or from the biomass, wherein the culturing is carried out in a mineral salt medium containing n-alkanes with 10 to 20 carbon atoms as the sole source of carbon and in the form of an aerated submersion culture.

PATENT ABSTRACTS

4681841

E N Z Y M A T I C A S S A Y M E T H O D

Kunio Matsumoto. Tsutomu Hirata, Shizuoka, Japan assigned to Toyo Jozo Kabushiki Kaisha

A method for assaying a compound of the for- mula See Patent for Chemical Structure wherein RI is hydroxyl or amino, or hydrogen if at least one of R2, R3, R4, R5 and R6 is hydroxyl or amino, and R2. R3, R4, R5 and R6 are hydro- gen. halogen, lower alkyl, lower atkoxy, amino, substituted amino, hydroxy, carboxyl or sulfo, or R5 and R6 together form a ring, comprises establishing a reaction system containing the compound to be assayed and a coupler and an enzyme capable of consuming oxygen and gene- rating a pigment in the presence of the com- pound and the coupler. A detectable change in the reaction system is measured, to assay the compound in question. The measurement can comprise the measurement of consumed oxygen, as by an oxygen electrode. Or the measurement can comprise the measurement of the generated pigment, as by a colorimetric assay at a specific absorption wavelength thereof.

4680267

F E R M E N T O R C O N T R O L S Y S T E M

Lee Eppstein, Robert D Mohler, Shaul Reuveny assigned to New Brunswick Scientific Company Inc

A method and an apparatus for controlling the concentration of oxygen and pH of a medium during a bioreaction process in a vessel. The method and apparatus are particularly adapted to a fermentation process. A dissolved oxygen sensor generates a signal corresponding to the pH of the medium and a dissolved oxygen sensor generates a signal corresponding to the dissolved oxygen in the medium. A valve mechanism selec- tively applies air, N2, 02 and CO2 to the medium. A controller produces a control signal for controlling the operation of the valve means so that a substantially fixed volume of gas con- sisting of one or more of air, CO2, N2 and 02 are added to the fermenting medium during a period of time. The controller determines in response to the dissolved oxygen and pH signals, the amount of CO2, O2 and/or N2 required to effect dis- solved oxygen and pH correction. The controller further adjusts these determined values to com- pensate for the displacement of the CO2 added. As a result, the effect of the CO2 correction on the dissolved oxygen is substantially minimized.

4681843

I M M O B I L I Z A T I O N O F C E L L S A N D E N Z Y M E S

Peter Egerer, Wulf Crueger, Christia Golker, Wuppertak Federal Republic Of Germany as- signed to Bayer Aktiengesellschaft

When immobilizing cells and/or enzymes by contact with tannin, epihalohydrin/polyamine copolymer and glutaraldehyde, immobilizing is carried out in the presence of a primary amine. The primary amine is preferably sulfuric acid mono-(2-aminoethyl)-ester, 2-aminoethanol, glycine or tris-(hydroxymethyl)-amino methane. The resulting immobilized cells and/or enzymes retain a higher proportion of their original ac- tivity.

4682654

E N Z Y M A T I C A L L Y - T R E A T E D G U A R G U M S

Walter Carter, Vinai K Srivastava assigned to Millmaster Onyx Group Inc

A method of recovering oil from an oil-bearing formation by fraetionation, utilizing as oil-