Complex sentence: Acetogens can use and convert alcohols, lactates and fatty acids that are usually restricted to syntrophs, instead of just carbon dioxide and hydrogen and this enables them to take on the roles of important contributors of food chain such as primary fermenters.
Split into simpler sentences: Acetogens can use and convert alcohols, lactates and fatty acids, which are usually restricted to syntrophs, instead of just carbon dioxide and hydrogen. This enables them to take on the roles of important contributors of food chain such as primary fermenters.