Cybernetic structured modeling of the production of polyhydroxyalkanoates by Alcaligenes Eutrophus

Abstract

This paper presents a cybernetic structured mathematical model developed for the fermentation step of the process of production of the copolymer of polyhydroxyalkanoates by the bacteria Alcaligenes eutrophus. This process is performed in two different fermentation stages. The first emphasizes the growth of the microorganism in a batch operation without substrates limitations, while in the second, the focus is on copolymer production by a fed-batch operation in the absence of the nitrogen source. This paper presents the results of the treatment of experimental data and of preliminary parameter estimation. The fitting of the proposed model to the experimental data of a standard experiment showed a good agreement

Mathematical Modelling as a Tool for Optimized PHA Production

“…Ferraz and coworkers 138 established a cybernetic model for PHA synthesis by A. eutrophus (today: C. necator) DSM 545, containing 53 parame-ters (among them 14 fixed and 39 adjustable) and 25 equations. A preliminary estimation of adjustable model parameters was achieved using model linearizations and simplifications as well as the treated experimental data.…”

“…The formerly described model by Ferraz et al 138 was further elaborated and improved by Riascos and Pinto 141 . The authors proposed the use of orthogonal collocation to a simultaneous optimization approach.…”

“…The authors proposed the use of orthogonal collocation to a simultaneous optimization approach. Initially, this methodology was implemented to the model of penicillin biosynthesis that was simplified to some extent; thereafter it was applied to a cybernetic structured model for PHA synthesis 138 . The model was intended for optimizing PHB and PHBV production by A. eutrophus (today: C. necator).…”

Produção biotecnológica de poli-hidroxialcanoatos para a geração de polímeros biodegradáveis no Brasil

“…O erro destes parâmetros torna-se significa-tivo, podendo causar problemas quando da formulação e do ajuste de parâmetros do modelo matemático, ou mesmo quando for utilizado em escala industrial. Considerando este fato, modelos matemáticos do processo de produção de PHB-co-HV foram propostos por vários autores 17,[89][90][91] , que propuseram modelo fenomenológico estruturado cibernético para o processo de produção de copolímeros de poli-hidroxialcanoatos em biorreator por A. eutrophus. Modificações foram feitas nesse mesmo modelo para estudos de otimização do processo, nos quais foram analisados os dados experimentais obtidos em biorreator empregando a estequiometria da via metabó-lica de produção de PHA por A. eutrophus 16,92,93 .…”

“…Um grande esforço foi realizado [12][13][14][15][16][17][18][19][20][21] e resultou no desenvolvimento de processo de produção de PHB e PHBco-HV, dois polímeros da família dos PHA, a partir de sacarose como fonte de carbono principal, que foi transferido para a empresa PHB Industrial S/A 22 , havendo no momento diversos trabalhos de caracterização e aplicação dos PHA.…”