title: Production of H(2) from cellulose by rumen microorganisms: effects of inocula pre-treatment and enzymatic hydrolysis.
abstract: H2 production from cellulose, using rumen fluid as the inoculum, has been investigated in batch experiments. Methanogenic archaea were inhibited by acid pre-treatment, which also inhibited cellulolytic microorganisms, and in consequence, the conversion of cellulose to H2. Positive results were observed only with the addition of cellulase. H2 yields were 18.5 and 9.6 mmol H2 g cellulose(-1) for reactors with 2 and 4 g cellulose l(-1) and cellulase, respectively. H2 was primarily generated by the butyric acid pathway and this was followed by formation of acetic acid, ethanol and n-butanol. In reactors using 4 g cellulose l(-1) and cellulase, the accumulation of alcohols negatively affected the H2 yield, which changed the fermentation pathways to solventogenesis. PCR-DGGE analysis showed changes in the microbial communities. The phylogenetic affiliations of the bands of DGGE were 99 % similar to Clostridium sp.
authors.affiliation: Department of Hydraulics and Sanitation, School of Engineering of São Carlos, University of São Paulo, Av. João Dagnone, 1100, Jd. Santa Angelina, São Carlos, CEP 13563-120, SP, Brazil.
authors.forename: Regiane Priscila
authors.initials: RP
authors.lastname: Ratti
authors.forename: Lívia Silva
authors.initials: LS
authors.lastname: Botta
authors.forename: Isabel Kimiko
authors.initials: IK
authors.lastname: Sakamoto
authors.forename: Edson Luiz
authors.initials: EL
authors.lastname: Silva
authors.forename: Maria Bernadete Amâncio
authors.initials: MB
authors.lastname: Varesche
mesh_terms: D000818:Animals; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D058448:Biota; D001826:Body Fluids / Q000382:microbiology*; D002417:Cattle; D002482:Cellulose / Q000378:metabolism*; D058645:Denaturing Gradient Gel Electrophoresis; D006859:Hydrogen / Q000378:metabolism*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010802:Phylogeny; D012417:Rumen / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D006859:Hydrogen; D002482:Cellulose