Deep-sea hydrothermal vents are characterized by extremely high concentrations of microorganisms in stark contrast to the surrounding sea bottom. Nevertheless, deepsea consumers do not rapidly remove the high biomass of prey from these communities maybe due to vent microbes’ chemical defenses which still remain largely unknown. Meanwhile, the detection of genes responsible for antimicrobial and cytotoxic activity such as non-ribosomal peptide synthases (NRPS) and polyketide (PKS) of deep-sea vent bacteria has not so far been attempted.