Fig. 4. Effect of the inhibition of archaeal and bacterial metabolism.

Reported are, from left to right, viral abundance, bacterial 16S rRNA gene copies in the extracellular DNA, and archaeal 16S rRNA gene copies in the extracellular DNA, during time-course incubations of untreated (control, blue bars) and treated (light blue bars, following addition of GC7 plus antibiotics to inhibit archaeal and bacterial metabolism) deep-sea sediment samples. Reported are average values and SDs. Asterisks indicate the significant increase (**P < 0.01) in the abundance of viruses and the number of bacterial or archaeal 16S rRNA gene copies after 12 hours of incubation in untreated (control) samples. ns, no significant differences occurring over time in treated samples; rDNA, ribosomal DNA.