Lee An, Cheng Kuan-Chen, Liu Je-Ruei
Graduate Institute of Food Science and Technology, National Taiwan University, Taipei, Taiwan.
Institute of Biotechnology, National Taiwan University, Taipei, Taiwan.
PLoS One. 2017 Aug 1;12(8):e0182220. doi: 10.1371/journal.pone.0182220. eCollection 2017.
Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by Fusarium species, which has been shown to be associated with reproductive disorders in livestock, and to a lesser extent with hyperoestrogenic syndromes in humans. The aim of this study was to characterize a Bacillus amyloliquefaciens strain with ZEN removal ability. A pure culture of a strain designated LN isolated from moldy corn samples showed a high ZEN removal capability. Based on microscopic observations, biochemical characteristics, and phylogenetic analysis of the 16S rRNA gene sequence, LN was identified as B. amyloliquefaciens. After incubation of B. amyloliquefaciens LN in Luria-Bertani (LB) medium containing 3.5 ppm of ZEN, the ZEN concentration fell below the detection limit within 24 h. In ZEN-contaminated corn meal medium, B. amyloliquefaciens LN decreased ZEN concentration by 92% after 36 h of incubation. In phosphate-buffered saline (PBS) containing 5 ppm of ZEN, B. amyloliquefaciens LN reduced the ZEN concentration from 5 ppm to 3.28 ppm immediately after coming into contact with ZEN, and further reduced the ZEN concentration to 0.36 ppm after 4 h of incubation. The amounts of ZEN adsorbed by the cells of B. amyloliquefaciens LN did not increase with the extension of incubation time, indicating that B. amyloliquefaciens LN not only possessed ZEN adsorption ability, but also exhibited the ability to degrade ZEN. In addition, B. amyloliquefaciens LN was non-hemolytic, non-enterotoxin producing, and displayed probiotic characteristics including acidic tolerance, bile salt tolerance, and anti-pathogenic activities. These findings suggest that B. amyloliquefaciens LN has a potential to be used as a feed additive to reduce the concentrations of ZEN in feedstuffs.
玉米赤霉烯酮（ZEN）是一种由镰刀菌属产生的非甾体雌激素类霉菌毒素，已被证明与家畜的生殖紊乱有关，在一定程度上也与人类的高雌激素综合征有关。本研究的目的是鉴定一株具有去除ZEN能力的解淀粉芽孢杆菌菌株。从发霉玉米样品中分离出的一株命名为LN的纯培养菌株显示出较高的ZEN去除能力。基于显微镜观察、生化特性以及16S rRNA基因序列的系统发育分析，LN被鉴定为解淀粉芽孢杆菌。将解淀粉芽孢杆菌LN在含有3.5 ppm ZEN的Luria-Bertani（LB）培养基中培养后，ZEN浓度在24小时内降至检测限以下。在受ZEN污染的玉米粉培养基中，解淀粉芽孢杆菌LN培养36小时后，ZEN浓度降低了92%。在含有5 ppm ZEN的磷酸盐缓冲盐水（PBS）中，解淀粉芽孢杆菌LN与ZEN接触后，ZEN浓度立即从5 ppm降至3.28 ppm，培养4小时后进一步降至0.36 ppm。解淀粉芽孢杆菌LN细胞吸附的ZEN量并未随着培养时间的延长而增加，这表明解淀粉芽孢杆菌LN不仅具有ZEN吸附能力，还表现出降解ZEN的能力。此外，解淀粉芽孢杆菌LN不产生溶血毒素和肠毒素，并表现出益生菌特性，包括耐酸性、耐胆盐性和抗致病活性。这些发现表明，解淀粉芽孢杆菌LN有潜力用作饲料添加剂，以降低饲料中ZEN的浓度。
