EJPAU 2005. Miśkiewicz T. , Borowiak D. A LOGISTIC FEEDING PROFILE FOR A FED-BATCH BAKER'S YEAST PROCESS

Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.

2005
Volume 8
Issue 4

Topic:

Biotechnology

ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES

Miśkiewicz T. , Borowiak D. 2005. A LOGISTIC FEEDING PROFILE FOR A FED-BATCH BAKER'S YEAST PROCESS, EJPAU 8(4), #35.
Available Online: http://www.ejpau.media.pl/volume8/issue4/abs-35.html

A LOGISTIC FEEDING PROFILE FOR A FED-BATCH BAKER'S YEAST PROCESS

Tadeusz Miśkiewicz, Daniel Borowiak
Department of Bioprocess Engineering, Wroclaw University of Economics, Poland

ABSTRACT

The study reported on in this paper has shown that the optimisation of the fed-batch baker’s yeast process by maximising the biomass yield needs a feeding profile differing from the one used in the optimisation of this process by maximising the specific growth rate. Both the profiles can be described by a logistic function of the formula F(t) = a/(1+b·exp(-c·t)), where F(t) denotes the moment of the glucose feed entering the bioreactor in time t, and a, b and c are parameters of the equation. The parameters take different values, depending on the objective of the optimisation process. It has also been demonstrated that the two objectives, maximisation of the biomass yield and maximisation of the specific growth rate, conflict with each other. A compromise feeding profile was proposed, thus enabling the maximisation of the criterion which was the product of the biomass yield and specific growth rate (Y·µ). The criterion reached its maximal value in the bakers yeast process with a biomass yield and specific growth rate of 0.58 g·g^-1and 0.129 h^-1, respectively.

Key words: baker?s yeast process, biomass yield, logistic feeding profile, Saccharomyces cerevisiae, specific growth rate.

Tadeusz Miśkiewicz
Department of Bioprocess Engineering,
Wroclaw University of Economics, Poland
Komandorska 118/120, 53-345 Wroclaw, Poland
phone: +48 71 3680269
fax: +48 71 680753
email: tadeusz.miskiewicz@ae.wroc.pl

Daniel Borowiak
Department of Bioprocess Engineering,
Wroclaw University of Economics, Poland
Komandorska 118/120, 53-345 Wroclaw, Poland
phone: +48 71 3680269
fax: +48 71 680753
email: daniel.borowiak@ae.wroc.pl

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.