We investigated predator-prey interactions in a model system consisting of the bacterivorous flagellate Poterioochromonas sp. strain DS and the freshwater bacterium Sphingobium sp. strain Z007. This bacterial strain tends to form a subpopulation of grazing-resistant microscopic flocs, presumably by aggregation. Enhanced formation of such flocs could be demonstrated in static batch culture exper...

The action of 22 antimicrobial agents against the SA2f strain of Chlamydia trachomatis has been studied by the use of a simple cell culture technique. Tests for bactericidal activity were undertaken with some of the agents, and latency of infection was demonstrated. The susceptibilities of 10 clinical strains of C. trachomatis and of SA2f to oxytetracyline, erythromycin, and spectinomycin in ce...

Quiescent Escherichia coli cells are generated by overexpressing the Rcd transcript in an hns-205 mutant host. The resulting nongrowing, metabolically active cells were used here to express a single-chain antibody fragment (scFv) in shake flask and fermentor cultures. The expression system is based on two plasmids; one carries the product gene expressed from lambdaP(L) under the control of the ...

Mild hypothermia condition in mammalian cell culture technology has been one of the main focuses of research for the development of breeding strategies to maximize productivity of these production systems. Despite the large number of studies that show positive effects of mild hypothermia on specific productivity of r-proteins, no experimental approach has addressed the indirect effect of lower ...

The cybernetic framework developed by Ramkrishna and co-workers has been expanded to include the effects of cellular maintenance energy requirements on biomass levels in slow-growing, carbon-substrate-limited cultures. A simple structured model, based on the existence of distinct key enzymes for growth and maintenance functions, is presented. Comparisons of the model with experimental data for ...

MATERIALS AND METHODS Virus Two strains of rubella virus were used, Judith (McCarthy & Taylor-Robinson, 1965) and Thomas, the latter having been isolated at St Thomas's Hospital in 1966 from an infant with congenital rubella. Judith was propagated in both RK 13 and BHK-21 cell cultures. Since its original isolation, Thomas had been passed eight times in RK 13 and BHK-21 cell cultures. Titres of...

• Creating new purification and culture techniques for neural cells, • Making new antibodies to visualize protein distribution or control signaling between cells, • Constructing new interfering RNAs and breeding transgenic animals to control gene expression and protein production • Developing new models to study biological mechanisms and evaluate therapeutic effects in cell culture, animal mode...

Recombinant alkaline polygalacturonate lyase (PGL) production by recombinant Pichia pastoris GS115 was selected as a model to study as a continuous culture strategy for enhancing heterologous protein production based on controlling methanol feeding (CCCM culture) or on dual carbon source feeding (CCCD culture). Using the CCCM process with a dry cell weight of 75 g/L regulated by controlling met...

Animal and two-dimensional cell culture models have had a profound impact on not only lung research but also medical research at large, despite inherent flaws and differences when compared with in vivo and clinical observations. Three-dimensional (3D) tissue models are a natural progression and extension of existing techniques that seek to plug the gaps and mitigate the drawbacks of two-dimensi...

The principal objective of this study was to evaluate the kinetics of dihydroxyacetone production by Gluconobacter frateurii CGMCC 5397 under different oxygen volumetric mass transfer coefficient (kLa) conditions in submerged bioreactors using biodiesel-derived crude glycerol as the carbon source. kLa is a key fermentation parameter for the production of dihydroxyacetone. Cultivations were cond...