A morphologically structured model for penicillin production

Abstract

A morphologically structured model is proposed to describe penicillin production in fed-batch cultivations. The model accounts for the effects of dissolved oxygen on cell growth and penicillin production and variations in volume fractions of abiotic and biotic phases due to biomass formation. Penicillin production is considered to occur in the subapical hyphal cell compartment and to be affected by availability of glucose and oxygen. As it stands, the model provides a wide range of applicability in terms of operating conditions. The model has been tested for various conditions and has given satisfactory results. A series of glucose feeding profiles have been considered to demonstrate the capabilities of the proposed model. It is concluded that the model may be valuable for the interpretation of experimental data collected specifically for metabolic flux analysis during fed-batch cultivation because the elements of measured specific production rates are determined from measurements of the concentrations of the components and their mass balances. The proposed model may be further used for developing control strategies and model order reduction algorithms.

A Population-Based Morphologically Structured Model for Hyphal Growth and Product Formation in Streptomycin Fermentation

“…In their model assumptions, the apical compartment was responsible for hyphal extension, and the subapical compartment branched to form new apical compartment, which was a good approach to experimental observations, for branching seldom occurs in the rear part of the hypha. The Nielsen model was further applied in simulation of penicillin fermentation and retamycin fermentation with good agreement (Zangirolami et al 1998;Birol et al 2002;Giudici et al 2004). Based on the quantitative measurement of morphological differentiation with an image analytical system, Paul & Thomas (1996) incorporated hyphal differentiation into the morphologically structured model for penicillin fermentation process.…”

Cell-mass maximization in fed-batch cultures

“…Hamiltonian function H 1 a part of Hamiltonian function PI performance index S substrate concentration (g/cm 3 ) S m substrate concentration at which l is maximum (g/cm 3 ) S Y substrate concentration at whichY X=S is maximum (g/cm 3 ) S 0 initial substrate concentration (g/cm 3 ) t time (s) t F time at which the bioreactor is full (s) t f final time (s) V bioreactor volume (cm 3 ) V max maximum bioreactor volume (cm 3 ) V 0 initial volume (cm 3 ) V s volume at the start of singular feed rate (cm 3 ) x state vector (x 1 x 2 x 3 x 4 ) T x 1 total cell mass (g) x 2 total substrate (g) x 3 bioreactor volume (cm 3 ) x 4 auxiliary state to handle the final time in PI (s) X cell-mass concentration (g/cm 3 ) X 0 initial cell-mass concentration (g/cm 3 ) X s cell-mass concentration at the start of singular feed rate (g/cm 3 ) $ cell mass price per unit weight of cell mass $ operating operating cost per unit time…”

“…Cell-mass production in fed-batch fermentation process is a typical singular control problem [1][2][3][4][5][6][7][8][9]. For a fixed reactor volume with one feed rate of limiting substrate, the general feed rate profile is known as bang-singular-bang, i.e.…”

Multiway kernel independent component analysis based on feature samples for batch process monitoring

“…During this stage biomass growth rate must be kept constant to maintain high penicillin production. So a readily metabolisable sugar such as glucose is supplied continuously into the system instead of being added all at once at the beginning [4,3]. We obtain the batch data using a modular simulator (PenSim v2.0) for fed-batch fermentation developed by the monitoring and control group of the Illinois Institute of Technology in the year of 2002 [10].…”