Introduction Cell based therapy requires great numbers of cells in a functional state permitting their in vivo implantation for the restoration of tissue homeostasis. Three main parameters are believed to be essential for such a purpose: an appropriate cell population, a suitable scaffold and appropriate physical / biochemical factors enabling proper expansion and in vitro cell differentiation....

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...

A mathematical model describing the behavior of a continuous culture that degrades 1,2-dichloroethane and receives a shock loading of another compound was developed. The model takes into account possible cell death due to toxicity, growth inhibition and additional growth of cells on the second carbon source. Biodegradation is coupled to cell growth on the additional carbon source or by incomple...

Background When scaling up a monoclonal antibody (mAb) production process in stirred tank bioreactor, oxygen transfer is probably one of the most challenging parameters to consider. Approaches such as keeping constant specific power input or tip speed across the scales are widely described in the literature and are often based on the assumption that mammalian cells are sensitive to shear stress...

A multiplexed microbioreactor system for parallel operation of multiple microbial fermentation is described. The system includes miniature motors for magnetic stirring of the microbioreactors and optics to monitor the fermentation parameters optical density (OD), dissolved oxygen (DO), and pH, in-situ and in real time. The microbioreactors are fabricated out of poly(methylmethacrylate)(PMMA) an...

The present study is concerned with the effect of low pH on continuous citric acid fermentation by Aspergillus niger strain SK-17. Microbial cultivations were carried out in a stainless steel stirred bioreactor of 15 L total capacity. The bioconversion of glucose to citric acid at low pH was investigated on cellulose fabric. Sucrose solution (100 g/l) was made to flow through capillaries of a v...

This paper studies the problem of designing controllers for enlarging the stability region of continuous stirred microbial bioreactors. A specific application is in anaerobic digestion, where the stability region can be very small if the operating steady state is selected to maximize the methane production rate. A control Lyapunov function approach is followed to construct a globally stabilizin...

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-...

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...