中国被毛孢降解黄曲霉毒素B1的特性研究

Study on the characteristics of aflatoxin B1 degradation by Hirsutella sinensis

中文关键词:  黄曲霉毒素B1  中国被毛孢  生物降解  薄层层析

英文关键词:aflatoxin B1  Hirsutella sinensis  microbiological degradation  thin layer chromatography

中文摘要:

      目的 分析中国被毛孢(Hirsutella sinensis) 8#菌株降解黄曲霉毒素B1 (aflatoxin B1, AFB1)的能力。方法 考察该菌株培养液、菌丝体悬液和上清液去除AFB1的能力; 利用洗脱法和萃取法区分生物降解和可逆吸附AFB1; 研究不同初始AFB1浓度、温度、pH和金属离子对其降解能力的影响; 对AFB1降解液进行高效液相色谱(high performance liquid chromatography, HPLC)和薄层色谱(thin layer chromatography, TLC)分析。结果 H. sinensis培养液和菌丝体悬液降解效果显著(P<0.05), 96 h后对初始质量浓度100 ng/mL的AFB1降解率分别是96.90%±4.39%和97.93%±2.92%。磷酸盐缓冲液洗脱液和甲醇萃取液均未检测到AFB1, 证实了该菌生物降解AFB1。菌株AFB1降解效果与初始质量浓度密切相关。当反应温度25℃, pH 5.0时, 培养液作用72 h后降解率为99.90%±0.18%。同时, 反应液中加入Fe2+有利于降解, 而Mg2+却起到了抑制作用。HPLC和TLC对产物分析表明, 该菌株可将AFB1降解为至少为1种产物。结论 中国被毛孢8#菌株对AFB1有良好的降解作用, 可用于生物降解真菌毒素的潜力菌株。

英文摘要:

      Objective To analyze the capability of Hirsutella sinensis 8# on the degradation of aflatoxin B1 (AFB1). Methods The capability of removing AFB1 from the culture solution, the mycelium suspension and the supernatant of the strain was investigated; the elution and extraction methods were used to decide whether the toxin wa biodegradation or reversibly bound; the effects of the initial AFB1 concentration of the medium, reaction temperature, pH and metal ion on degradation were studied; the products of AFB1 degradation were detected by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). Results The degradation effects of H. sinensis culture medium and bacteria were significant (P<0.05), and after 96 h, the degradation rates of AFB1 at the initial mass concentration of 100 ng/mL were 96.90%±4.39% and 97.93%±2.92%, respectively. The absence of AFB1 in either the phosphate buffer eluant or the methanol extract confirmed the biodegradation of AFB1. The degradation effect of strain AFB1 was closely related to the initial mass concentration. When the reaction temperature was 25℃ and pH was 5.0, the degradation rate of the culture solution after 72 h treatment was 99.90%±0.18%. At the same time, the addition of Fe2+ in the reaction solution was conducive to the degradation, while Mg2+ played an inhibitory role. Product analysis by HPLC and TLC showed that the strain degraded AFB1 to at least one product. Conclusion H. sinensis 8# has a good degradation effect on AFB1 and can be used as a potential strain for biodegradation of mycotoxins.