This paper deals with the vibrational control of a recycled bioprocess, which takes place into a Continuous Stirred Tank Bioreactor (CSTB). The classical control techniques for bioreactors necessitate measurements of states and/or disturbances. However, the bioprocesses are systems that require costly and difficult on-line implementation for sensors. Vibrational control is a non-classical open-...

Background Currently, stirred tank reactors (STR) represent the gold standard for the large scale growth of suspension cell lines. Culture performance is strongly influenced by the efficiency of mixing, as measured by the mass transfer coefficient and mixing time. The success of traditional stainless steel or glass STR systems lies in their impeller driven agitation that efficiently mixes large...

Embryonic stem (ES) cells can differentiate into functional hepatic lineage cells, which can potentially be used in biomedicine. To obtain hepatic lineage cells from ES cells, embryoid bodies (EBs) must be formed. In this study, we developed an EB formation system using a spinner flask for mass production of EBs. ES cells were inoculated into the spinner flask, where they formed EBs within 4 d....

Problem Statement: Mixing filamentous fungi entails delicate balance between promoting high volumetric oxygen transfer coefficient (kLa) while keeping low hydrodynamic stresses in the microenvironment of cultures. This study examined the oxygen transfer capability of a prototype low shear helical impeller as a potential replacement for the standard Rushton turbine. Approach: The dependence of k...

The bioreduction of solid TNT by a Pseudomonas fluorescens strain was investigated in a stirred tank reactor. Experiments in which TNT beads were the only solids present indicated that the biodegradation mechanism is dissolution followed by degradation in bulk solution. Dissolution may limit the overall rate, in which case degradation can be enhanced through increased agitation. Since soil slur...

Statistically designed experiments were used to optimize the production of arginine deiminase (ADI) by Pseudomonas putida KT2440 in batch culture. A Plackett-Burman design involving eleven factors showed that ADI production was most influenced by the initial pH and the initial concentrations of glucose and yeast extract. A central composite experimental design showed that the optimal values of ...

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...

Background: Although the citric acid fermentation by Aspergillus niger is one of the most important industrial microbial processes and various aspects of the fermentation appear in a very large number of publications since the 1950s, the effect of the spore inoculum level on fungal morphology is a rather neglected area. The aim of the presented investigations was to quantify the effects of chan...

Statistical analyses were applied to optimize the medium composition for the mycelial growth and polysaccharide production by Tremella aurantialba in shake flask cultures. Firstly, four significant factors (xylan, peptone, wheat bran and corn powder) on mycelial growth and polysaccharide yield (p£0.05) were obtained using one-at-a-time design. Subsequently, in order to study the mutual interact...

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...