On-line monitoring of intracellular enzyme activities with flow-injection analysis

✍ Scribed by K. Steube; U. Spohn

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 952 KB
• Volume: 287
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(93)e0601-d

✦ Synopsis

Micromethods for rapid and reproducible cell disintegration were combined with flow-injection analysis @IA) to determine intracellular enzyme activities. Flow through chambers were developed for cell disintegration by the action of ultrasonic, ultraturrax and glass microball-mixer mills. A membrane device was incorporated into the FIA set-up to separate the cell debris and the released enzyme from the disintegrated sample solution. After mixing with the corresponding enzyme substrate the assay reaction takes place. The reaction product is transferred into the inlet tube of a fluorescence detector. Dehydrogenase activities were determined in the range of 0.001-2 U/ml with relative standard deviations < 1% (n = 4, e = 0.05). The measuring set-up was completed by a chemically sterilized on-line sampling device connected to a bioreactor. Intracellular formate dehydrogenase and malate dehydrogenase were on-line determined to monitor yeast cultivation processes.