Study on the Directional Breeding of High Glutamic-acid Production Strain GTS190 and the Control on Its Fermentation

摘要

Using Brevibacterium flavum CN1021 as starting strain, the L-glutamate producing strain was directionally bred with protoplast UV mutagenesis, UV mutagenesis and DES mutagenesis. Through shake-tube preliminary screening, shake-flask re-screening, genetic markers verification and continuous passage, an L-glutamate temperature-sensitive mutant strain GTS190 (T~s＋Omr＋GluHX~r＋SG~r＋FEA~r＋AECr＋Suc~g) was screened finally. It was fermented for 36h in a vessel (30L) feeding by batches, in which glutamic acid production reached 195 g/L and sugar and acid conversion rate was 66%.