Conditions For Large-scale Production Research Articles

Concentration of baboon endogenous virus in large-scale production by use of hollow-fiber ultrafiltration technology.

A process is described in which the baboon endogenous virus (BaEV) is produced under optimum conditions in cell culture, and concentrated by hollow-fiber ultrafiltration technology under conditions of large-scale production. This system has advantages over conventional systems in that the flow rate is increased 2.5-fold during concentration. Thermal inactivation of BaEV was retarded by the addition of lactose glutamate to the harvested tissue culture fluid. After concentration, at least 91% of the virus RNA-directed DNA polymerase is recovered with a concomitant increase in infectious virus. Materials needed for modifying described systems may be obtained from commercial sources.

Substitution of protein feed through lysine-supplemented high-protein wheat during the rearing and laying period of hens. 4. Effect of graded lysine doses during the rearing of young hens on the performance characteristics during the laying period

1530 laying hybrid hens kept under conditions of large-scale production were used to test whether varying lysine levels given to young hens would later on influence the production of the birds during their laying period. Thus, young hens received isonitrogenous and isocaloric diets with varying lysine content (group 1-4: 0.59%, 0.61%, 0.54%, 0.46%) and varying sources of lysine (group 1: wheat/fish meal; group 2--4: wheat/synthetic L-lysine). The ration used for the controls was prepared on the basis of nationally prescribed formulas.

Production of tumor-inhibitory L-asparaginase by submerged growth of Serratia marcescens.

Production of a tumor-inhibitory asparaginase by submerged fermentation with Serratia marcescens ATCC 60 was studied to ascertain optimal nutritional conditions for large-scale production leading to enzyme purification studies. Five strains of S. marcescens were screened in shake-flask studies and were found to produce 0.8 to 3.7 IU/ml 48 hr after inoculation. The requirements for asparaginase production with S. marcescens ATCC 60, the high producing strain, included the following: 4% autolyzed yeast extract medium (initial pH 5.0), an incubation temperature of 26 C, and limited aeration for a zero level of dissolved oxygen during the fermentation. Addition of various carbohydrates to the fermentation medium did not enhance yields. The peak cell population in the fermentation medium and the maximal asparaginase yields occurred simultaneously. Highest enzyme yields were found when the pH of the fermentation cycle rose to approximately 8.5. Yields of 4 IU of asparaginase/ml of cell suspension have been obtained consistently in 40 to 42 hr from 10-liter volumes (500 ml/4-liter bottle) produced on a reciprocating shaker. Scale-up to a 60-liter fermentor yielded 3.1 IU/ml in 35 hr.

Large-scale Production of Anti-lymphocytic Antibody

The Wellcome Foundation is part of the M.R.C. Working Party on A.L.S. and the main role of the Foundation, as agreed with the Working Party as a whole, is to produce A.L.S. on a large scale for use in man.In Great Britain, the use of any new therapeutic agent is controlled by authority, in this case the Dunlop Committee. Before this committee could be approached for a licence to market such a product, it would be necessary for the pharmaceutical company concerned to have established conditions for large-scale production.

Production of Tumor-Inhibitory L-Asparaginase by Submerged Growth of Serratia marcescens1

Production of a tumor-inhibitory asparaginase by submerged fermentation with Serratia marcescens ATCC 60 was studied to ascertain optimal nutritional conditions for large-scale production leading to enzyme purification studies. Five strains of S. marcescens were screened in shake-flask studies and were found to produce 0.8 to 3.7 IU/ml 48 hr after inoculation. The requirements for asparaginase production with S. marcescens ATCC 60, the high producing strain, included the following: 4% autolyzed yeast extract medium (initial pH 5.0), an incubation temperature of 26 C, and limited aeration for a zero level of dissolved oxygen during the fermentation. Addition of various carbohydrates to the fermentation medium did not enhance yields. The peak cell population in the fermentation medium and the maximal asparaginase yields occurred simultaneously. Highest enzyme yields were found when the pH of the fermentation cycle rose to approximately 8.5. Yields of 4 IU of asparaginase/ml of cell suspension have been obtained consistently in 40 to 42 hr from 10-liter volumes (500 ml/4-liter bottle) produced on a reciprocating shaker. Scale-up to a 60-liter fermentor yielded 3.1 IU/ml in 35 hr.