한국 서해안 강화도갯벌의 배양가능한 철환원세균의 다양성

Abstract

Rates and pathways of organic matter oxidation in the intertidal flat depend on the availability of electron acceptors (i.e., O2, metal oxides and sulfate, etc.). Because of the abundant sulfate in the sea water, sulfate reduction has been regarded as a major oxidation process in anoxic coastal sediment. However, recent studies revealed that metal reducing processes including iron reduction was responsible for most carbon oxidation in the rhizosphere of near burrows of benthic invertebrates. We investigated the diversity of iron reducing bacteria in association with the marsh plant (Suaeda japonica) using analysis of 16S rRNA gene sequences of enrichment culture with FeOOH as an electron acceptor. Clones affiliated into the genus Clostridium, Desulfovibrio, Desulfuromonas and Shewanella appeared to be dominant groups. Approximately 50% of the 488 clones showed relatively high similarity with known species of the genus Clostridium but produced a distinct phyletic line. Overall results indicated that novel microorganisms related to the genus Clostridium might responsible for app. 30% of organic matter oxidation in salt marsh environments via metal reducing process.