8→88-3g-33 Individual Population Community 2 Community 1 Oxic zone. Photic zone cyanobacteria and(6,+6H,0- C2H,2O2+602 Chemoorganotrophic actena c.H.0.+60 6C0+6H.O Sediments Anoxic zone Community 3 1.Guild 1: methanogenic bacteria(CO,CH) homoacetogenic bacteria(Co,acetate) 2. Guild 2: sulfate-reducing bacteria (So-H,S) sulfur-reducing bacteria (S H 3. Guild 3: denitrifying bactena (NO ferric iron-reducing bacteria(Fe-Fe") 4: Guild 4: fermentative bacteria (fermenting sugars, amino and fatty acids