title: On-line coupling of a miniaturized bioreactor with capillary electrophoresis, via a membrane interface, for monitoring the production of organic acids by microorganisms.
abstract: Capillary electrophoresis (CE) can be a valuable tool for on-line monitoring of bioprocesses. Production of organic acids by phosphorus-solubilizing bacteria and fermentation of UHT milk were monitored and controlled by use of a membrane-interfaced dialysis device and a home-made microsampler for a capillary electrophoresis unit. Use of this specially designed sampling device enabled rapid consecutive injections without interruption of the high voltage. No additional sample preparation was required. The time resolution of monitoring in this particular work was approximately 2 h, but could be reduced to 2 min. Analytes were detected at low microg mL(-1) levels with a reproducibility of approximately 10%. To demonstrate the potential of CE in processes of biotechnological interest, results from monitoring phosphate solubilization by bacteria were submitted to qualitative and quantitative analysis. Fermentation experiments on UHT milk showed that monitoring of the processes by CE can provide good resolution of complex mixtures, although for more specific, detailed characterization the identification of individual substances is needed.
authors.affiliation: Institute of Basic and Applied Chemistry, Tallinn Technical University, Estonia.
authors.forename: S
authors.initials: S
authors.lastname: Ehala
authors.forename: I
authors.initials: I
authors.lastname: Vassiljeva
authors.forename: R
authors.initials: R
authors.lastname: Kuldvee
authors.forename: R
authors.initials: R
authors.lastname: Vilu
authors.forename: M
authors.initials: M
authors.lastname: Kaljurand
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism; D000818:Animals; D001419:Bacteria / Q000737:chemistry / Q000378:metabolism; D019149:Bioreactors; D002264:Carboxylic Acids / Q000032:analysis* / Q000378:metabolism*; D003956:Dialysis; D019075:Electrophoresis, Capillary; D004867:Equipment Design; D005942:Gluconates / Q000032:analysis / Q000378:metabolism; D019344:Lactic Acid / Q000032:analysis / Q000378:metabolism; D008832:Microchemistry; D008892:Milk / Q000378:metabolism; D009862:Online Systems; D010710:Phosphates / Q000378:metabolism; D012988:Soil Microbiology
chemical_list: D002264:Carboxylic Acids; D005942:Gluconates; D010710:Phosphates; D019344:Lactic Acid; D019342:Acetic Acid; C030691:gluconic acid