Diversification of bacterial community composition along a temperature gradient at a thermal spring.
To better understand the biogeography and relationship between temperature and community structure within microbial mats, the bacterial diversity of mats at a slightly alkaline, sulfide-containing hot spring was explored. Microbial mats that developed at temperatures between 75-52°C were collected from an area of approximately 1 m(2) in Nakabusa, Nagano, Japan. Bacterial 16S rRNA genes from these samples were examined by terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis. T-RFLP profiles revealed 66 unique fragments (T-RFs). Based on total T-RFs observed in environmental profiles and clone libraries, a temperature effect on diversity was determined, with complexity in the community increasing as temperature decreased. The T-RF pattern indicated four distinct community assemblages related to temperature. Members of the Aquificales and particularly the sulfur-oxidizing bacterium Sulfurihydrogenibium were present at all temperatures and were the dominant component of mats taken at 75-67°C. Sulfide oxidation, which persisted throughout the temperature gradient, was the presumed dominant pathway of primary production above 67°C. As temperature decreased, successive additions of anoxygenic and oxygenic phototrophs increased primary productivity, allowing for diversification of the community.
Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1–1 Minami-Osawa, Hachioji-shi, Tokyo 192–0397, Japan.
R Craig
RC
Everroad
Hiroyo
H
Otaki
Katsumi
K
Matsuura
Shin
S
Haruta
D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001483:Base Sequence; D044822:Biodiversity; D017753:Ecosystem; D005798:Genes, Bacterial; D045482:Hot Springs / Q000382:microbiology*; D007564:Japan; D059013:Microbial Consortia; D008969:Molecular Sequence Data; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017423:Sequence Analysis, RNA; D013696:Temperature; D014871:Water Microbiology
D012336:RNA, Ribosomal, 16S