Purpose: To investigate the structure and function of the complex rumen microbial community in a
biogas reactor by 16S rRNA gene analysis, which was fed with Pennisetum sinese Roxb as the monosubstrate.
Methods: Two 16S ribosomal RNA (rRNA) clone libraries of bacteria and archaea were established by
polymerase chain reaction. Community structure was determined by phylogenetic analyses of 119 and
100 16S rRNA gene clones from the bacterial and archaeal libraries, respectively.
Results: In the bacterial library, 13.4 % of clones were affiliated with
Treponema porcinum
, 5.9 % with
Eubacterium limosum
, 5 % with Clostridium, 5 % with Bacteroidetes, 4.2 % with Firmicutes, 2.5 % with
Anaerofilum and a total of 64 % clones belonged to unclassified or uncultured bacteria. In the archaeal
library, Methanobacterium curvum made up 12 % of known clones,
Methanosarcina barkeri
represented
8 %,
Methanobacterium bryantii
represented 4 % and
Methanofollis ethanolicus
represented 2 %,
respectively; the remaining 74 % of the clones were unclassified archaebacteria.
Conclusion: T. porcinum and M. curvum are the most predominant bacteria and archaea in a biogas
reactor fed with P. sinese as the sole substrate.
