title: Hydrogen-producing microflora and Fe-Fe hydrogenase diversities in seaweed bed associated with marine hot springs of Kalianda, Indonesia.
abstract: Microbial fermentation is a promising technology for hydrogen (H(2)) production. H(2) producers in marine geothermal environments are thermophilic and halotolerant. However, no one has surveyed an environment specifically for thermophilic bacteria that produce H(2) through Fe-Fe hydrogenases (H(2)ase). Using heterotrophic medium, several microflora from a seaweed bed associated with marine hot springs were enriched and analyzed for H(2) production. A H(2)-producing microflora was obtained from Sargassum sp., 16S rRNA genes and Fe-Fe H(2)ase diversities of this enrichment were also analyzed. Based on 16S rRNA genes analysis, 10 phylotypes were found in the H(2)-producing microflora showing 90.0-99.5 % identities to known species, and belonged to Clostridia, Gammaproteobacteria, and Bacillales. Clostridia were the most abundant group, and three Clostridia phylotypes were most related to known H(2) producers such as Anaerovorax odorimutans (94.0 % identity), Clostridium papyrosolvens (98.4 % identity), and Clostridium tepidiprofundi (93.1 % identity). For Fe-Fe H(2)ases, seven phylotypes were obtained, showing 63-97 % identities to known Fe-Fe H(2)ases, and fell into four distinct clusters. Phylotypes HW55-3 and HM55-1 belonged to thermophilic and salt-tolerant H(2)-producing Clostridia, Halothermothrix orenii-like Fe-Fe H(2)ases (80 % identity), and cellulolytic H(2)-producing Clostridia, C. papyrosolvens-like Fe-Fe H(2)ases (97 % identity), respectively. The results of both 16S rRNA genes and Fe-Fe H(2)ases surveys suggested that the thermophilic and halotolerant H(2)-producing microflora in seaweed bed of hot spring area represented previously unknown H(2) producers, and have potential application for H(2) production.
authors: Shandong Provincial Key Laboratory of Microbial Engineering, School of Food and Bioengineering, Shandong Institute of Light Industry, Jinan 250353, Shandong, People's Republic of China.
authors: Shou-Ying
authors: SY
authors: Xu
authors: Pei-Qing
authors: PQ
authors: He
authors: Seswita-Zilda
authors: SZ
authors: Dewi
authors: Xue-Lei
authors: XL
authors: Zhang
authors: Chasanah
authors: C
authors: Ekowati
authors: Tong-Jun
authors: TJ
authors: Liu
authors: Xiao-Hang
authors: XH
authors: Huang
mesh_terms: D056449:Bacillales / Q000145:classification / Q000235:genetics; D003013:Clostridium / Q000145:classification / Q000235:genetics; D020563:Gammaproteobacteria / Q000145:classification / Q000235:genetics; D045482:Hot Springs / Q000382:microbiology*; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000235:genetics / Q000378:metabolism*; D007214:Indonesia; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D054892:Metagenome; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012624:Seaweed / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D007506:Iron-Sulfur Proteins; D012336:RNA, Ribosomal, 16S; D006859:Hydrogen; C118830:iron hydrogenase; D006864:Hydrogenase