Monitoring the rumen pectinolytic bacteriaTreponema saccharophilumusing real-time PCR

Abstract

Treponema saccharophilum is a pectinolytic bacterium isolated from the bovine rumen. The abundance of this bacterium has not been well determined, reflecting the lack of a reliable and accurate detection method. To develop a rapid method for monitoring T.saccharophilum, we performed pyrosequencing of genomic DNA isolated from rumen microbiota to explore the 16S rRNA gene sequences of T.saccharophilum candidates. Species-specific primers were designed based on fifteen sequences of partial 16S rRNA genes generated through pyrosequencing with 97% or higher similarity with T.saccharophilum DSM2985 along with sequence from type strain. The relative abundance of T.saccharophilum was quantified in both in vitro and in vivo rumen systems with varied pectin-containing forages using real-time PCR. There was a clear association of T.saccharophilum with alfalfa hay, which contains more pectin than Chinese wild rye hay or corn stover. The relative abundance of T.saccharophilum was as high as 0.58% in vivo, comparable with the population density of other common rumen bacteria. It is recognized that T.saccharophilum plays an important role in pectin digestion in the rumen.