Abstract
Mutants of Bacillus brevis No. 47 that grew in synthetic media containing a high concentration of ammonium sulfate were stable and had high protein production. Among various antibiotics tested, inhibitors of cell wall synthesis, such as bacitracin or β-lactam antibiotics, were effective in greatly increasing the accumulation of exoproteins.
When 60μg/ml of bacitracin was added to the culture at the early logarithmic growth phase, about 9mg/ml of proteins was produced. Such a protein yield was estimated to be nearly maximum from a given amount of glucose. Alterations in cell wall components were found in cells grown in the presence of bacitracin. Possible relationships between cell wall structure and protein production were discussed.
