ARTP Mutain Breeding of Naringinase-Producing Strains and Optimization of Fermentation Conditions

Abstract:

Atmospheric and room temperature plasma（ARTP） was used to mutagenize Alternaria alternate which is a naringinase-producing strain. The naringinase activity of the mutagenized stain SK37.002 reached 327.32 U/mL，which was 208% higher than that of original strain.The optimum carbon sources for naringinase-producing is sucrose. The most suitable inducer is naringin and nitrogen sources being NaNO3. According to Plackett-Burman design，NaNO3，CaCl2 and K2HPO4 were screened out of 8 factors as main affecting variables of naringinase production. Then steepest ascent method was used to approach themaximum response regions and it was followed by Box-Behnken and response surface analysis. As a result，the optimum medium formula（g/L） determined was composed of naringin 1，sucrose 5，NaNO3 5，K2HPO4 0.8，CaCl2 0.7，KCl 0.5，MgCl2 0.5. The resulting naringinase activity in fermentation broth reached up to 624.73±30.33 U/mL and was 90% higher than before which was consistent with the predicted maximum value.