Kf. Hansen et H. Degn, ONLINE MEMBRANE INLET MASS-SPECTROMETRY FOR FEEDBACK-CONTROL OF PRECURSOR CONCENTRATION IN PENICILLIN FERMENTATION, Biotechnology techniques, 10(7), 1996, pp. 485-490
A sampling system which enables on-line measurements of the precursor
phenoxyacetic acid (POAA) in penicillin fermentation by membrane inlet
mass spectrometry is presented and its capacity for feed-back regulat
ion of POAA to a low predefined concentration in a penicillin-V fermen
tation over 150 hours is demonstrated. The system measures alternately
filtered sample and standard solution in a measuring cycle which is s
horter than the response time of membrane inlet mass spectrometry (MIM
S) but sufficiently long to decide whether the concentration of POAA i
n the sample is higher or lower than in the standard solution at set p
oint concentration. The decision is used for on-off regulation of the
addition of POAA.