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Diverse microbial communities inhabiting ferromanganese deposits in Lechuguilla and Spider Caves
Author(s) -
Northup Diana E.,
Barns Susan M.,
Yu Laura E.,
Spilde Michael N.,
Schelble Rachel T.,
Dano Kathleen E.,
Crossey Laura J.,
Connolly Cynthia A.,
Boston Penelope J.,
Natvig Donald O.,
Dahm Clifford N.
Publication year - 2003
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1046/j.1462-2920.2003.00500.x
Subject(s) - biology , ferromanganese , archaea , cave , geomicrobiology , proteobacteria , crenarchaeota , manganese , microorganism , bacteria , ecology , 16s ribosomal rna , chemistry , paleontology , environmental biotechnology , organic chemistry
Summary Lechuguilla Cave is an ancient, deep, oligotrophic subterranean environment that contains an abundance of low‐density ferromanganese deposits, the origin of which is uncertain. To assess the possibility that biotic factors may be involved in the production of these deposits and to investigate the nature of the microbial community in these materials, we carried out culture‐independent, small subunit ribosomal RNA (SSU rRNA) sequence‐based studies from two sites and from manganese and iron enrichment cultures inoculated with ferromanganese deposits from Lechuguilla and Spider Caves. Sequence analysis showed the presence of some organisms whose closest relatives are known iron‐ and manganese‐oxidizing/reducing bacteria, including Hyphomicrobium , Pedomicrobium , Leptospirillum , Stenotrophomonas and Pantoea . The dominant clone types in one site grouped with mesophilic Archaea in both the Crenarchaeota and Euryarchaeota. The second site was dominated almost entirely by lactobacilli. Other clone sequences were most closely related to those of nitrite‐oxidizing bacteria, nitrogen‐fixing bacteria, actinomycetes and β‐ and γ‐Proteobacteria. Geochemical analyses showed a fourfold enrichment of oxidized iron and manganese from bedrock to darkest ferromanganese deposits. These data support our hypothesis that microorganisms may contribute to the formation of manganese and iron oxide‐rich deposits and a diverse microbial community is present in these unusual secondary mineral formations.