POTENTIOMETRIC BIOSENSOR FOR CONTROL OF BIOTECHNOLOGICAL PRODUCTION OF PENICILLIN-G

A pa-membrane electrode with tridodecylamine as a hydrogen ion-selecti ve ionophore was used for the construction of a biosensor for the benz ylpenicillin determination. The electrode was enzymatically modified b y covalent binding of penicillinase directly to the membrane surface. The high sensitivity and short response time of the biosensor allow it s application in flow injection analysis (FIA). Up to 30 samples per h our can be analyzed in the flow system. The FIA system with the biosen sor was successfully used for the determination of penicillin G in fer mentation broth. An optimized analytical procedure results in minimiza tion of interferences from pH and buffer capacity of the real samples. No interferences from inorganic, organic and bioorganic components pr esent in the fermentation medium were observed. An important advantage of the presented analytical system is the long-term stability due to the long lifetime of the biosensor. Consequently fermentation bioproce sses can be controlled using the same biosensor for about two months. Due to the high sensitivity and selectivity, the presented method for the penicillin determination in real biotechnological samples gives an alytical results comparable to those obtained using methods recommende d by pharmacopoeias. (C) 1998 Elsevier Science B.V. All rights reserve d.