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Deep-sea sediments show decreasing nutrient levels with depth and thus the microbes that reside there experience constant near-starvation conditions. Although not yet cultured, novel phyla of Archaea inhabit deep marine sediments (as well as the terrestrial deep subsurface), and these organisms likely survive by scavenging the trace levels of both organic matter and electron acceptors present there.
What are sources of organic matter in deep-sea sediments that could be used to support growth?
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Brock Biology of Microorganisms (15th Edition)
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