Acetogens
inhabitating the rhiyosphere of sea grasses
Sea grasses are important to the
productivity of estuarine
ecosystems. They are rooted in reduced
anoxic sediments, and the rhizosphere is enriched with anaerobic
microorganisms. However, during the day, photosynthetic oxygen
production
generates oxygen gradients around the roots.
Thus, obligate anaerobes have to tolerate periods of elevated
oxygen
tensions.
A sea grass
meadow
This project is focused on the detection
and
characterization of acetogens within the roots with 16S rRNA probes and
functional gene probes. Root thin
sections hybridized with 16S rRNA probes reveal that acetogens occur
mostly in
the rhizoplane and outermost cortex cell layers. The
capacity of acetogenic isolates obtained from seagrass roots
to tolerate and consume limited amounts of oxygen might enable them to
survive
in a habitat subject to daily gradients of photosynthesis-derived
oxygen.