School of Bioengineering, Dalian University of Technology, Dalian, 116024, China.
Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry, Beijing Technology and Business University, Beijing, 100048, China.
Curr Microbiol. 2021 Oct;78(10):3686-3695. doi: 10.1007/s00284-021-02624-4. Epub 2021 Aug 18.
Aflatoxin B (AFB) contamination in feed and food seriously threatens the healthy growth of animals and humans, and it may lead to huge economic losses in livestock and poultry production. Therefore, screening of high-efficient AFB-degrading bacteria is necessary to ensure the safety of feed and food. The study aims to isolate and characterize bacteria from various sources to explore its AFB degradation potential. Fifteen bacterial were obtained using a medium containing coumarin as the sole carbon source; only one strain showed a good-degrading ability in culture media by adding AFB and it was selected for further studies. A gram-negative and spore-forming, designated E1, was identified as Paenibacillus pabuli, with the highest sequence similarity to P. pabuli NBRC13638 (98.97%). The growth of the strain E1 was observed under 22-47 °C, pH 5.5-9.5 and NaCl concentration 0-6% (w/v), with optimum growth at 37 °C, pH 7.5 and 1% NaCl. The biodegradation characteristics of object strain were detected by high performance liquid chromatography (HPLC). The degradation ratio of AFB reached 55% at 24 h and 70.2% at 48 h. After 96 h, the degradation rate of AFB reached 85.9%. The active degradation components were present in the cell-free supernatant of strain E1, and the degradation ratio of AFB reached 80.0% after 96 h. It is the first report that genus Paenibacillus could degrade AFB. Moreover, E1 has highly adaptable to diverse environmental conditions. It will be a potential candidate for biodegradation of mycotoxins in feed and food.
黄曲霉毒素 B（AFB）污染饲料和食品严重威胁动物和人类的健康成长，并可能导致畜牧业和家禽生产的巨大经济损失。因此，筛选高效的 AFB 降解菌对于确保饲料和食品的安全是必要的。本研究旨在从各种来源中分离和鉴定细菌，以探索其 AFB 降解潜力。使用含有香豆素作为唯一碳源的培养基获得了 15 株细菌；只有一株在添加 AFB 的培养基中表现出良好的降解能力，因此被选为进一步研究的对象。一株革兰氏阴性、芽孢形成的细菌，命名为 E1，被鉴定为解淀粉芽孢杆菌，与解淀粉芽孢杆菌 NBRC13638（98.97%）的序列相似度最高。该菌株 E1 的生长在 22-47°C、pH5.5-9.5 和 0-6%（w/v）的 NaCl 浓度下观察到，最适生长温度为 37°C、pH7.5 和 1%NaCl。通过高效液相色谱（HPLC）检测了目标菌株的生物降解特性。AFB 的降解率在 24 小时时达到 55%，在 48 小时时达到 70.2%。96 小时后，AFB 的降解率达到 85.9%。在菌株 E1 的无细胞上清液中存在活性降解成分，96 小时后 AFB 的降解率达到 80.0%。这是首次报道解淀粉芽孢杆菌能够降解 AFB。此外，E1 对各种环境条件具有高度适应性。它将是饲料和食品中生物降解霉菌毒素的潜在候选物。
