Recombinant protease mutant, coding gene, vector, engineering bacterium and application in splitting (R, S)-2-ethyl tetrahydrofuroate

The invention discloses a recombinant protease mutant, a coding gene, a carrier, an engineering bacterium and application of the recombinant protease mutant to resolution of (R, S)-2-ethyl tetrahydrofuroate, and the application is as follows: taking supernatant crude enzyme liquid obtained by fermentation culture of bacillus subtilis SCK6 or pure enzyme liquid obtained by purification of the crude enzyme liquid as a catalyst, taking racemic (R, S)-ethyl tetrahydrofuroate as a substrate, and carrying out enzymatic hydrolysis on the racemic (R, S)-2-ethyl tetrahydrofuroate to obtain the recombinant protease mutant, the coding gene, the carrier, the engineering bacterium and the resolution of the (R, S)-2-ethyl tetrahydrofuroate. According to the method, ethyl (S)-2-tetrahydrofuroate and (R)-2-tetrahydrofuroic acid are prepared through resolution under the conditions that the temperature is 10-60 DEG C and the speed is 500-1500 rpm by taking a phosphate buffer solution with the pH value being 8.0 as a reaction m