We consider a model for bioremediation of a pollutant by bacteria in a well-stirred bioreactor. A key feature is the inclusion of dormancy for bacteria, which occurs when the critical nutrient level falls below a critical threshold. This feature gives a discrete component to the system due to the change in dynamics (governed by a system of ordinary differential equations between transitions) at...

Background Single-use bioreactors continue to gain large interest in the biopharmaceutical industry. They are excessively used for mammalian cell cultivations, e.g. production of monoclonal antibodies and vaccines [1]. This is motivated by several advantages of these bioreactors like reduced risk of cross contaminations or shortening lead times [2]. Singleuse bioreactors differ in terms of shap...

Enzymatic hydrolysis of lactose by -galactosidase (Lactozym) has been studied in a jacketed stirred-tank reactor (JSTR) and in a recirculation hollow-%bre bioreactor (RHFB). The hollow-%bre module was manufactured with modi%ed cellulose-acetate membrane (Cuprophan). The variables tested were: temperature (25–40◦C), lactose concentration (0.0278–0:208 M) and enzyme concentration (0.100–4:51 g l−...

(Received: May 11, 2011; June 13, 2011) Abstract: In the most cases of the practical fermentation processes with filamentous microorganisms, direct monitoring of the cell morphology and biomass distribution in the culture medium is not easily possible. Use of a mathematical model is a suitable way to describe the substrate uptake and cell growth behavior of these microorganisms. Penicillium bre...

Heparin and heparan sulfate are structurally-related carbohydrates with therapeutic applications in anticoagulation, drug delivery, and regenerative medicine. This study explored the effect of different bioreactor conditions on the production of heparin/heparan sulfate chains via the recombinant expression of serglycin in mammalian cells. Tissue culture flasks and continuously-stirred tank reac...

A fuzzy-decision-making procedure is applied to find the optimal feed policy of a fed-batch fermentation process for L-lysine production in a stirred tank bioreactor from Brevibacterium flavum 22LD. The policy consists of a feed flow rate, feed concentration of glucose and threonine, and fermentation time. In this paper the fermentation process is formulated as a general multiple objective opti...

This paper presents the design and the analysis of some adaptive nonlinear control strategies for a class of depollution fermentation processes that are carried out in a continuous stirred tank bioreactor. The controllers design is based on the input-output linearization technique. The resulted control methods are applied in depollution control problem in the case of the anaerobic digestion bio...

Background The commercial success of mammalian cell-derived recombinant proteins has fostered an increase in demand for novel single-use bioreactor (SUB) systems, that facilitate greater productivity, increased flexibility and reduced costs. Whilst maintaining auspicious mixing parameters, these systems exhibit fluid flow regimes unlike those encountered in traditional glass/stainless steel bio...

A novel source of biological nitrogen produced by multi-strain fermentation was developed for erythromycin production. The nitrogen composition of corn steep liquor, biological nitrogen and soybean flour was optimized by using Response surface methodology (RSM) firstly. A Box-Behnken design was used to estimate the optimum nitrogen composition for the production of erythromycin as follows: corn...

Phenylethanoids are a group of natural water-soluble compounds with high biological value, which could potentially be commercially produced by hairy root cultures. Thus, we have examined the capacity of transformed root cultures of Devil's claw (Harpagophytum procumbens) to accumulate four phenylethanoid glycosides -beta-OH-verbascoside, verbascoside, leucosceptoside A, and martynoside--in shak...