Lactose was used to replace isopropyl β-D-1-thiogalactopyranoside (IPTG) as inducer, the feeding strategy was optimized to improve cell density, induction strategy was studied for improvement of L-glutamate oxidase (LGOX) activity, the whole-cell conversion biocatalyst from high cell density fermentation was used to produce a-ketoglutaric acid (a-KG) from L-glutamic acid. The results showed that LGOX activity was up to 4.78 U/mL from 3.12 U/mL by IPTG induction in the shake flask. In a 5 L fermenter, cell density was increased from 2.49 to 41.6 g/L, and LGOX activity reached 59 U/mL with two-stage feeding strategy combining the exponential feeding with DO-stat feeding strategy. By optimizing the induction strategies, the maximal cell density and LGOX activity reached 48.4 g/L and 156.1 U/mL, improvement of 19.4- and 50-fold before optimization, respectively. a-KG yield was up to 5160 g/L by whole-cell conversion, increased by 48-fold.