title: Microbial diversity of a mesophilic hydrogen-producing sludge.
abstract: A hydrogen-producing sludge degraded 99% of glucose at 36 degrees C and pH 5.5, producing a methane-free biogas (comprising 64% hydrogen) and an effluent comprising mostly butyrate, acetate, and ethanol. The yield was 0.26 l H2 g(-1) glucose and the production rate per gram of volatile suspended solids was 4.6 1 H2 day(-1). A 16S rDNA library was constructed from the sludge for microbial species determination. A total of 96 clones were selected for plasmids recovery, screened by denaturing gradient gel electrophoresis, and sequenced for rDNA. Based on the phylogenetic analysis of the rDNA sequences, 64.6% of all the clones were affiliated with three Clostridium species (Clostridiaceae), 18.8% with Enterobacteriaceae, and 3.1% with Streptococcus bovis (Streptococcaceae). The remaining 13.5% belonged to eight operational taxonomic units, the affiliations of which were not identified.
authors.affiliation: Centre for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China. hrechef@hkucc.hku.hk
authors.forename: H H P
authors.initials: HH
authors.lastname: Fang
authors.forename: T
authors.initials: T
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Liu
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D019149:Bioreactors; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics; D006859:Hydrogen / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D006859:Hydrogen