ESTIMATION OF BIOMASS AND SPECIFIC GROWTH-RATE IN A RECOMBINANT ESCHERICHIA-COLI BATCH CULTIVATION PROCESS USING A CHEMICAL MULTISENSOR ARRAY

A chemical multisensor array is used in combination with an artificial neural network to estimate the biomass concentration and specific gro wth rate in a recombinant Escherichia coli batch cultivation. It is sh own that by providing sufficient information to the artificial neural network, an accuracy comparable to that of an established dry weight m ethod can be achieved. The obtained prediction error (1 sigma) of 0.04 3 g 1(-1) for biomass compares well with the error of the dry weight m ethod in this low biomass concentration range (0.1-3 g 1(-1)). The pre diction for the specific growth rate is accurate during important part s of the cell growth (1 sigma = 0.025 h(-1)). The results show that th is non-invasive method is potentially useful for estimating biomass an d specific growth rate on-line in bioprocesses. (C) 1998 Elsevier Scie nce B.V. All rights reserved.