Abstract: Methods for microbiological processing of organic materials for production of valuable products. Asymmetric hollow fibers are employed in a flow reactor, where the hollow fibers have a semipermeable membrane surrounding a lumen, where the semipermeable membrane is supported by a sponge structure. The pores of the sponge structure serve as a housing for microorganisms or cells with high density packing of the microorganisms or cells in the pores. Nutrient medium continuously flowing through the lumen provides nutrients to the microorganisms or cells as well as any substrates to be processed by the microorganisms or cells. The nutrients and substrates diffuse through the semipermeable membrane into the pores, where they are processed, and the metabolic products diffuse into the lumen. The lumen effluent is then processed for the desired products. Optionally, oxygen is provided external to the hollow fiber to enhance the amount of oxygen available to the microorganisms and cells.

Abstract: Improved cell culture microcarriers having controlled amphipathic (hydrophobic and polar) properties and controlled positive charge capacities, which make these microcarriers controllable in size in aqueous or non-aqueous environments and which produce outstanding growth of anchorage-dependent cells, and methods for their use.

Abstract: A method for continuous fermentation in which carbohydrate solution is fed continuously into a fermentation zone containing substantially homogeneously distributed yeast and carbohydrate solution whereby the carbohydrate is fermented to ethanol, a proportion of the fermenting liquid continuously passing to a pressurised settling tank, yeast depleted liquid being withdrawn from the upper part of the settling tank and yeast enriched liquid being withdrawn from the lower part of said tank and returned to the fermentation zone, a proportion of yeast being withdrawn without being returned to the fermentation zone, said proportion being such that the concentration of yeast in the fermentation zone is substantially constant, and the pressure within the settling tank is sufficient to prevent the formation of gaseous carbon dioxide. The method enables rapid continuous fermentation to take place using high concentrations of yeast. Apparatus for operating the method is described.