解淀粉芽孢杆菌诱变育种及其突变株在降低酱油中氨基甲酸乙酯的应用

【目的】通过诱变育种提高解淀粉芽孢杆菌JY06利用精氨酸的能力,并将其用于降低酱油中的氨基甲酸乙酯及前体,从而提高酿造酱油的安全性。【方法】采用等离子诱变和紫外诱变两种诱变育种方法对解淀粉芽孢杆菌JY06进行突变,应用高通量筛选手段获得具有高精氨酸利用能力的突变株,验证突变株降低酱油中氨基甲酸乙酯的能力。【结果】获得了12株精氨酸利用能力提高的突变株,与出发菌株JY06相比,突变株C12和E6可使酱油中瓜氨酸含量分别降低了15.6%和14.7%,EC的含量分别降低了19.3%和13.1%。【结论】通过等离子诱变和紫外诱变进一步提高了解淀粉芽孢杆菌JY06降低酱油中EC及其前体瓜氨酸的能力,具有控制或减少酱油中生物危害物的应用潜力。

Reduction of ethyl carbamate in soy sauce by Bacillus amyloliquefaciens mutants

[Objective] To prepare mutants of Bacillus amyloliquefaciens JY06 stain with enhanced arginine consumption capability to reduce carcinogenic compound ethyl carbamate and its precursors in soy sauce.[Methods] Atmospheric and room temperature plasma (ARTP) and UV mutagenesis were used to mutate Bacillus amyloliquefaciens JY06, and a high-throughput screening approach was used to characterize mutants with high arginine utilization capability. The properties of mutants were studied following addition to soy sauce moromi during fermentation to initiate reduction of citrulline and ethyl carbamate.[Results] Twelve mutants with elevated arginine utilizing ability were obtained through ARTP and UV mutagenesis, of which C12 and E6 displayed the highest capacity for eliminating EC and citrulline. Compared with the JY06 parent strain, the addition of C12 or E6 to the moromi during soy sauce fermentation decreased citrulline content in soy sauce by 15.6% and 14.7%, and reduced ethyl carbamate by 19.3% and 13.1%, respectively.[Conclusion] Both ethyl carbamate and its precursor citrulline were significantly decreased in soy sauce by B. amyloliquefaciens JY06 mutants in the moromi during fermentation, demonstrating the potential of the mutants to control or eliminate toxic compounds in soy sauce and similar food products.