title: Diversity and activity of enriched ruminal cultures of anaerobic fungi and methanogens grown together on lignocellulose in consecutive batch culture.
abstract: Consecutive batch cultures (CBC), involving nine serial transfers at 3, 5 and 7d intervals (21, 45 and 63d, respectively) were established to enrich for plant fibre degrading co-cultures of anaerobic fungi and methanogens from rumen digesta. Microbial diversity and fermentation end-products were measured at appropriate intervals over each CBC time-course. While methanogenic populations remained diverse, anaerobic fungal diversity was related to transfer interval and appeared to decrease with increasing transfer number. Acetate was the principal aqueous fermentation end-product with minimal quantities of lactate and formate detected. Methane and carbon dioxide were detected in the gaseous head-space of all co-cultures and the total amounts of gas generated per transfer was greater with transfer intervals of 5 and 7d compared with a 3d interval, although the 3d interval tended to be more efficient per unit time. In conclusion, rapidly growing, methane producing co-cultures of anaerobic fungi and methanogens from rumen digesta were easy to establish on lignocellulose (barley straw) and maintain over considerable time periods. These results suggest such co-cultures have potential in industrial scale anaerobic digestion (AD) of highly fibrous substrates, which are resistant to degradation in conventional AD plants.
authors.affiliation: College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
authors.forename: Yan Fen
authors.initials: YF
authors.lastname: Cheng
authors.forename: Joan E
authors.initials: JE
authors.lastname: Edwards
authors.forename: Gordon G
authors.initials: GG
authors.lastname: Allison
authors.forename: Wei-Yun
authors.initials: WY
authors.lastname: Zhu
authors.forename: Michael K
authors.initials: MK
authors.lastname: Theodorou
mesh_terms: D000085:Acetates / Q000032:analysis; D000693:Anaerobiosis; D000818:Animals; D001105:Archaea / Q000254:growth & development*; D044822:Biodiversity; D002245:Carbon Dioxide / Q000032:analysis; D018929:Cell Culture Techniques / Q000379:methods*; D005232:Fatty Acids, Volatile / Q000032:analysis; D005285:Fermentation; D005561:Formates / Q000032:analysis; D005658:Fungi / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000032:analysis; D008031:Lignin / Q000378:metabolism*; D008697:Methane / Q000378:metabolism*; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012417:Rumen / Q000382:microbiology*
chemical_list: D000085:Acetates; D005232:Fatty Acids, Volatile; D005561:Formates; D007773:Lactates; C030544:formic acid; C036909:lignocellulose; D002245:Carbon Dioxide; D008031:Lignin; D008697:Methane