A simple feeding strategy was developed and successfully employed for nutritional control in a 2-L fed-batch culture of hybridoma cells. A previously developed stoichiometric model for animal cell growth was used to design a supplemental medium for feeding. Undialyzed fetal bovine serum and trace metals (Fe(2+), SeO(3) (2-), Li(+), Zn(2+), and Cu(2+)) were fed to the cells periodically in addit...

A high beta-glucosidase (BGL)-producing strain, Stereum hirsutum, was identified and isolated and showed a maximum BGL activity (10.4 U/ml) when cultured with Avicel and tryptone as the carbon and nitrogen sources, respectively. In comparison with other BGLs, BGL obtained from S. hirsutum showed a higher level of activity to cellobiose (V(max) = 172 U/mg, and k(cat) = 281/s). Under the optimum ...

In order to see the effect of CO(2) inhibition resulting from the use of pure oxygen, we carried out a comparative fed-batch culture study of polyhydroxybutyric acid (PHB) production by Ralstonia eutropha using air and pure oxygen in 5-L, 30-L, and 300-L fermentors. The final PHB concentrations obtained with pure O(2) were 138.7 g/L in the 5-L fermentor and 131.3 g/L in the 30-L fermentor, whic...

BACKGROUND In comparison with phototrophic growth, heterotrophic conditions can significantly increase growth rates, final cell number and cell mass in microalgae cultures. Neochloris oleoabundans is a microalga of biotechnological interest that accumulates lipids under phototrophic and nitrogen-limited conditions. Heterotrophic flask culture experiments were conducted to identify carbon source...

The production of lactic acid from date juice by Lactobacillus caseisubsp. rhamnosus in batch and fed-batch cultures has been investigated. The fed-batch culture system gave better results for lactic acid production and volumetric productivity. The aim of this work is to determine the effects of the feeding rate and the concentration of the feeding medium containing date juice glucose on the ce...

On-line monitoring of insect cell cultures used for the production of recombinant proteins with the baculovirus expression vector system (BEVS) provides valuable tools for the optimization, operation, and control of the production process. The relative permittivity (epsilon') and CO(2) evolution rates (CER) were measured on-line using the biomass monitor and the infrared CO(2) analyzer, respect...

In this study, a mathematical model was proposed and the accuracy of this model was assessed to predict the growth of Pseudomonas aeruginosa and rhamnolipid production under nitrogen limiting (sodium nitrate) fed-batch fermentation. All of the parameters used in this model were achieved individually without using any data from the literature. The overall growth kinetic of the strain was evaluat...

Modeling and simulation of Polyhydroxybutyrate (PHB) production by Protomonas extorquens in fed-batch culture were conducted in this research. The fed-batch model, developed for this process, employed a kinetic model proposed by other researchers. Several kinetic models were investigated to choose the best model. The criterion for this selection was goodness of fit (δ2). Haldane kinetic model w...

The activation of caspases represents a crucial turning point during a batch or a fed-batch culture of mammalian cells. It not only affects the quantity but also the quality of the recombinant glycoprotein produced. In this study, the activation of various caspases, the release of intracellular sialidase and the changes in sialylation pattern of a recombinant product, erythropoietin (EPO), in t...