Novel Aflatoxin-Degrading Enzyme from Bacillus shackletonii L7
AbstractFood and feed contamination by aflatoxin (AF)B1 has adverse economic and health consequences. AFB1 degradation by microorganisms or microbial enzymes provides a promising preventive measure. To this end, the present study tested 43 bacterial isolates collected from maize, rice, and soil samples for AFB1-reducing activity. The higher activity was detected in isolate L7, which was identified as Bacillus shackletonii. L7 reduced AFB1, AFB2, and AFM1 levels by 92.1%, 84.1%, and 90.4%, respectively, after 72 h at 37 °C. The L7 culture supernatant degraded more AFB1 than viable cells and cell extracts; and the degradation activity was reduced from 77.9% to 15.3% in the presence of proteinase K and sodium dodecyl sulphate. A thermostable enzyme purified from the boiled supernatant was designated as Bacillus aflatoxin-degrading enzyme (BADE). An overall 9.55-fold purification of BADE with a recovery of 39.92% and an activity of 3.85 × 103 U·mg−1 was obtained using chromatography on DEAE-Sepharose. BADE had an estimated molecular mass of 22 kDa and exhibited the highest activity at 70 °C and pH 8.0, which was enhanced by Cu2+ and inhibited by Zn2+, Mn2+, Mg2+, and Li+. BADE is the major protein involved in AFB1 detoxification. This is the first report of a BADE isolated from B. shackletonii, which has potential applications in the detoxification of aflatoxins during food and feed processing. View Full-Text
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Xu, L.; Eisa Ahmed, M.F.; Sangare, L.; Zhao, Y.; Selvaraj, J.N.; Xing, F.; Wang, Y.; Yang, H.; Liu, Y. Novel Aflatoxin-Degrading Enzyme from Bacillus shackletonii L7. Toxins 2017, 9, 36.
Xu L, Eisa Ahmed MF, Sangare L, Zhao Y, Selvaraj JN, Xing F, Wang Y, Yang H, Liu Y. Novel Aflatoxin-Degrading Enzyme from Bacillus shackletonii L7. Toxins. 2017; 9(1):36.Chicago/Turabian Style
Xu, Liang; Eisa Ahmed, Mohamed F.; Sangare, Lancine; Zhao, Yueju; Selvaraj, Jonathan N.; Xing, Fuguo; Wang, Yan; Yang, Hongping; Liu, Yang. 2017. "Novel Aflatoxin-Degrading Enzyme from Bacillus shackletonii L7." Toxins 9, no. 1: 36.
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