Complex sentence: DNRA has been documented in prokaryotes inhabiting the upper layer of marine sediments; benthic sulfur bacteria such as "Beggiatoa" and "Thioploca" occur in anoxic sediments on continental shelves and obtain energy by oxidizing sulfide via DNRA.
Split into simpler sentences: DNRA has been documented in prokaryotes inhabiting the upper layer of marine sediments. Benthic sulfur bacteria such as "Beggiatoa" and "Thioploca" inhabit anoxic sediments on continental shelves and obtain energy by oxidizing sulfide via DNRA.