Methanobacterium - isolation & purification, Carbon Dioxide - metabolism, DNA, Ribosomal - analysis, Methane - metabolism, RNA, Ribosomal, 16S - analysis, Acetates - chemistry, Clostridium - genetics, Phylogeny, Clostridium - isolation & purification, Methanobacterium - genetics, Clostridium - classification, Biofilms, Sequence Analysis, RNA, Bioreactors - m...