Study Of Population Of Celluloytic Bacteria In Rumen By In Situ Hybridization 16S RRNA-targeted Specific Oligonucleotide Probes

In this investigation, we used nine Inner Mongolian wether sheep that had similar weight and steered with ruminal cannula. These sheep were divided with three groups and fed with mixed forages (concentrate :roughage ratio of 8:2) that were optimized by forage Grading Index (GI). These forges also were divided with three groups that was high GI (HGI), mid-GI (MGI) and low GI (LGI). They were fed with the three group sheep. The pH, concentration of NH3-N and volatilisable fatty acids (VFA) in the rumen were measured every two hours during trial. Through matching in the RDP database, we synthesized four 16S rRNA and one 18S rRNA probes that were three species of ruminal cellulolytic bacteria (ruminococcus flavefaciens, ruminococcus albus, baceroides succinogenes) bacteria current probe and fungi current probe and they were marked with digoxin. These oligonucleotide probes were hybridizated with RNA from content in rumen. We measured population of three cellulolytic bacteria and fungi and study the effect of optimized forages by GI on sheep ruminal fermentation, population of bacteria in rumen, explored a technology of 16S rRNA quantitative analysis. The result of this research as followed.1. Three group sheep were fed with HGI, MGI, LGI. We measured population of ruminococcus albus(2.69±0.60%, 1.80±0.04%, 1.77±0.75%), ruminococcus flavefaciens (2.54±0.55%, 1.91±0.29%, 3.66±1.10%), baceroides succinogenes (7.71±0.71%, 5.27±0.63%, 3.63±1.06%).2. Population of ruminococcus albus and baceroides succinogenes with feeding HGI had a significant different with other groups (p < 0.01); population of ruminococcus flavefaciens with feeding LGI is dominant to other bacteria; population of these three species of cellolytic bacteria in rumen fed with the three kinds of forages: HGI>MGI (p<0.01), HGI>LGI (p<0.01).3. After feeding with these forage, average population of the cellolytic bacteria in rumen was 2.09% (ruminococcus albus), 2.70% (ruminococcus flavefaciens) and 5.54% ( baceroides succinogenes), total amount is 10.35%.4. population of fungi in rumen: HGI>MGI>LGI. Among three groups had significant different (p<0.01).