What is "poribacteria"

Poribacteria are a candidate phylum of bacteria originally identified in the microbiome of sea sponges (Porifera). Poribacteria were distinguished from other microorganisms associated with sea sponges by their distinctive morphology featuring a large membrane-bound cellular compartment that frequently contains DNA, a highly unusual feature for a prokaryote. Poribacteria are Gram-negative mixotrophs.