骆驼瘤胃耐受/降解去氢骆驼蓬碱细菌的筛选

Screening of harmine tolerance/degrading bacteria from camel rumen

【目的】中药骆驼蓬含多种生物碱,对动物有毒性。生活于荒漠半荒漠的骆驼可采食部分有毒植物而不中毒。为了解骆驼瘤胃微生物对骆驼蓬植物毒素的耐受与降解能力进行本研究。【方法】以含100mg/L纯品去氢骆驼蓬碱的M98-5培养基接种骆驼瘤胃内容物,经五代胁迫培养后分离可耐受/降解去氢骆驼蓬碱的细菌,以薄层析法检验其降解活力,以16SrRNA序列分析其进化地位。【结果】29个分离株中15株具有降解去氢骆驼蓬碱活性;16SrRNA序列分析显示,属于乳杆菌属(Lactobacillus)16株,占55%;志贺氏菌属(Shigella)7株,占24%;芽孢杆菌属(Bacillus)4株,占13.8%;肠球菌属(Enterococcus)和巨型肠球菌属(Megasphaera)各1株。【结论】可耐受/降解去氢骆驼蓬碱的骆驼瘤胃细菌仅限于少数几类,且检测到的具有降解活力的只有乳杆菌类。

[ Objective] Peganum harmala, a famous traditional Chinese drug, contains a variety of alkaloids and toxic for many animals. Camels mainly live in desert or semi-desert areas, with the robust gastro-intestine system in digesting various feed including toxic plants without disease symptoms. [ Methods] Camel rumen content was used as the inoculant to inoculate medium M98-5 which contains 100 mg·L^-1 harmin and cultivated for 5 days. Upto 5 subculturings, strains that could degrading or tolerant harmine were isolated. Their conversion activity was determined by thin-layer chromatography. The taxonomic position of the strains were identified based on 16S rRNA sequences analysis. [ Results] 15 out of the 29 isolates have harmine degrading activity. Most of the isolates are identified as the members of the Genera Lactobacillus （16 strains, 55% ）, Shigella （7 strains, 24% ） and Bacillus （4 strains, 13.8% ）. Only one strain belong to genus Enterococcus and one belong to genus Megasphaera. [ Conclusion ] The results indicated that the harmine tolerance/degrading communities of camel rumen are limited and only Lactobacillus have harmine-degrading activity.