Clostridium grantii is a Gram-positive, strictly anaerobic, rod-shaped and spore-forming bacterium from the genus Clostridium which has been isolated from the gut of a mullet. C. grantii is able to break down alginate, a major component of brown algae. The species, along with other gut microbes, likely plays a role in breaking down algal material in the gut of mullet and other vegetation feeding marine fish.
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