On-line coupling of a miniaturized bioreactor with capillary electrophoresis, via a membrane interface, for monitoring the production of organic acids by microorganisms
S. Ehala et al., On-line coupling of a miniaturized bioreactor with capillary electrophoresis, via a membrane interface, for monitoring the production of organic acids by microorganisms, FRESEN J AN, 371(2), 2001, pp. 168-173
Capillary electrophoresis (CE) can be a valuable tool for on-line monitorin
g of bioprocesses. Production of organic acids by phosphorus-solubilizing b
acteria and fermentation of UHT milk were monitored and controlled by use o
f a membrane-interfaced dialysis device and a home-made microsampler for a
capillary electrophoresis unit. Use of this specially designed sampling dev
ice enabled rapid consecutive injections without interruption of the high v
oltage. No additional sample preparation was required. The time resolution
of monitoring in this particular work was approximately 2 h, but could be r
educed to 2 min. Analytes were detected at low tg mL(-1) levels with a repr
oducibility of approximately 10%. To demonstrate the potential of CE in pro
cesses of biotechnological interest, results from monitoring phosphate solu
bilization by bacteria were submitted to qualitative and quantitative analy
sis. Fermentation experiments on UHT milk showed that monitoring of the pro
cesses by CE can provide good resolution of complex mixtures, although for
more specific, detailed characterization the identification of individual s
ubstances is needed.