Metabolic studies of temperature control strategy on poly(γ-glutamic acid) production in a thermophilic strain Bacillus subtilis GXA-28

•A thermophilic strain B. subtilis GXA-28 and its product were characterized.•γ-PGA yield reach 19.92g/L and molecular weight reach 3.03×106Da at 45°C.•MFA results indicate that temperature presents a marked impact on γ-PGA production.•Enzyme activity analysis shows that ICDH and GDH are the positive regulators.•Provide a potential strain and a temperature control strategy for γ-PGA production.