蒙古绵羊瘤胃固、液相附着微生物的RT-PCR检测

 【目的】应用Real-time PCR（RT-PCR）对蒙古绵羊瘤胃内容物固、液相附着微生物的生态分布进行定量研究。【方法】采集3只蒙古绵羊瘤胃内容物,固液分离后对各相中所附着的微生物进行定量检测,包括总细菌、总厌氧真菌和3种主要纤维降解菌－白色瘤胃球菌Ruminococcus albus、黄色瘤胃球菌Ruminococcus flavefaciens、产琥珀酸拟杆菌Fibrobacter succinogenes。【结果】固相中总细菌、总厌氧真菌和3种纤维降解菌的16S或18S rRNA 基因考贝数显著高于液相,分别是液相附着微生物的7.22倍（P＜0.05）、56.85倍（P＜0.01）、2.69倍（P＜0.05）、4.19倍（P＜0.01）和7.59倍（P＜0.01）。瘤胃固相中F.succinogenes 菌的丰度为0.55%,高于R.flavefaciens 菌（0.53%）和R.albus菌（0.09%）。瘤胃液相中R.flavefaciens菌的丰度最高,为0.91%,高于F.succinogenes菌（0.52%）和R.albus 菌（0.24%）。【结论】RT-PCR方法能够准确对瘤胃固、液相附着微生物进行定量分析。

Quantity of Microorganisms Associated with Solid and Liquid Phases of Rumen Contents Using RT-PCR

【Objective】 Using Real-time PCR (RT-PCR)assays to quantify the microbes associated with particular phases of rumen contents. 【Method】 Whole rumen contents were sampled from three Mongolian sheep and partitioned into solid- and liquid-associated microorganisms. 【Result】 On the basis of 16S or 18S rRNA gene copy number analysis, the number of general bacteria, general anaerobic fungi and three representative ruminal cellulolytic bacteria (Ruminococcus albus, Ruminococcus flavefaciens, Fibrobacter succinogenes) associated with rumen solid content were 7.22-fold (P＜0.05), 56.85-fold (P＜0.01), 2.69-fold (P＜0.05), 4.19-fold (P＜0.01) and 7.59-fold (P＜0.01) as those associated with rumen liquid content. The abundance of F. succinogenes in the solid phase was 0.55%, which was higher than that of R. flavefaciens (0.53%) and R. albus (0.09%). However in the liquid phase R. flavefaciens accounted for 0.91% of the bacterial rRNA gene copies, which was more abundant than F. succinogenes (0.52%) and R. albus (0.24%). 【Conclusion】 RT-PCR method could accurately detect the distribution and abundance of microorganisms associated with particular phase of rumen content.