title: Comparative analysis of hydrogen-producing bacterial biofilms and granular sludge formed in continuous cultures of fermentative bacteria.
abstract: A system for biohydrogen production was developed based on long-term continuous cultures grown on sugar beet molasses in packed bed reactors. In two separate cultures, consortia of fermentative bacteria developed as biofilms on granitic stones. In one of the cultures, a granular sludge was also formed. Metagenomic analysis of the microbial communities by 454-pyrosequencing of amplified 16S rDNA fragments revealed that the overall biodiversity of the hydrogen-producing cultures was quite small. The stone biofilm from the culture without granular sludge was dominated by Clostridiaceae and heterolactic fermentation bacteria, mainly Leuconostocaeae. Representatives of the Leuconostocaeae and Enterobacteriaceae were dominant in both the granules and the stone biofilm formed in the granular sludge culture. The culture containing granular sludge produced hydrogen significantly more effectively than that containing only the stone biofilm: 5.43 vs. 2.8 mol H(2)/mol sucrose from molasses, respectively. The speculations that lactic acid bacteria may favor hydrogen production are discussed.
authors: Institute of Biochemistry and Biophysics PAS, Pawińskiego 5a, 02-106 Warsaw, Poland.
authors: Aleksandra
authors: A
authors: Chojnacka
authors: Mieczysław K
authors: MK
authors: Błaszczyk
authors: Paweł
authors: P
authors: Szczęsny
authors: Kinga
authors: K
authors: Nowak
authors: Martyna
authors: M
authors: Sumińska
authors: Karolina
authors: K
authors: Tomczyk-Żak
authors: Urszula
authors: U
authors: Zielenkiewicz
authors: Anna
authors: A
authors: Sikora
mesh_terms: D044822:Biodiversity; D018441:Biofilms / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology; D018929:Cell Culture Techniques / Q000379:methods*; D003013:Clostridium / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D005285:Fermentation / Q000502:physiology*; D006859:Hydrogen / Q000378:metabolism*; D056584:Leuconostocaceae / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D008965:Molasses; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage; D006859:Hydrogen