Isolation and characterization of a Bacillus subtilis strain with aflatoxin B1 biodegradation capability. (May 2017)

• Record Type: Journal Article
• Authors: Xia, Xiaoshuang; Zhang, Ye; Li, Mingyan; Garba, Betchem; Zhang, Qi; Wang, Yun; Zhang, Hongyin; Li, Peiwu
• Is Part Of: Food control. Volume 75(2017:May)
• Page Start: 92
• Page End: 98
• Publication Date: 2017-05
• Subjects: Mycotoxin -- Aflatoxin B1 -- Biodegradation -- Bacillus subtilis; Food -- Quality -- Periodicals; Food -- Analysis -- Periodicals; Food handling -- Periodicals; Food industry and trade -- Quality control -- Periodicals; Aliments -- Industrie et commerce -- Qualité -- Contrôle -- Périodiques; Aliments -- Qualité -- Périodiques; Aliments -- Analyse -- Périodiques; Hygiène alimentaire -- Périodiques; Food -- Analysis; Food handling; Food -- Quality; Periodicals; Electronic journals; 664.07
• DOI: 10.1016/j.foodcont.2016.12.036
• Languages: English
• ISSNs: 0956-7135

Abstract

Abstract: Aflatoxins are type of mycotoxins mainly produced by Aspergillus flavus and a common contaminant of food and grain, posing a serious economic and health problem worldwide. In order to find efficient bacteria to remove or detoxify these mycotoxins, a bacterial strain capable of degrading aflatoxin B1 (AFB1 ) was isolated from soil samples using a culture medium containing coumarin as the sole carbon source. Based on 16S rRNA gene sequence analysis, this isolate was identified as Bacillus subtilis JSW-1; its further characterization showed that it could inhibit the growth of A. flavus with an inhibition ratio of 58.3% and could degrade AFB1 by 67.2% after incubation at 30 °C for 72 h. The aflatoxin B1 -degrading activity of isolate JSW-1 was predominantly attributed to the cell-free supernatant and this activity was found to be heat stable but sensitive to proteinase K treatment, indicating that the extracellular proteins or enzymes are responsible for the AFB1 degradation. In addition, no degradation products of AFB1 could be detected by liquid chromatography-mass spectrometry (LC-MS) analysis, indicating that the parent AFB1 might be biotransformed to compounds with chemical properties different from that of AFB1 . Highlights: B. subtilis JSW-1 capable of AFB1 degradation was isolated and identified. Isolate of JSW-1 exhibits growth inhibition on A. flavus . Extracellular proteins of B. subtilis JSW-1 are responsible for AFB1 degradation. No degradation product of AFB1 can be detected by HPLC or LC-MS.