In fermentation of L-glutamate with acetic acid, an oleic acid auxotroph D-248 (OA
-) was superior to its parent strain,
Brevibacterium thiogenitalis No. 653 (Biotin
-) in amino acid production. The physiological properties of OA
- were then compared with those of Biotin
-. When both organisms were cultured in acetate media, the levels of acetate kinase and isocitrate lyase in OA
- were considerably higher than those in Biotin
-. No significant differences were found in other properties, such as cell permeability of L-glutamate, content of respiratory chain components and coupled oxidative phosphorylation efficiency.
Most revertants derived from OA
- revealed low L-glutamate productivity which was equal to or less than that of Biotin
-. A few revertants simultaneously obtained immediately after isolation showed relatively high productivity. These, however, were unstable. During storage in slant cultures, the productivity gradually decreased to the level of Biotin
-. These findings suggest that the mutation of Biotin
- to OA
- results in a marked increase in L-glutamate producing activity from acetate for L-glutamate producing
Brevibacterium.
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