β-Lactamases Are Absent from Archaea (Archaebacteria)

Abstract

ABSTRACT

β-Lactamases, enzymes that hydrolyze and inactivte β-lactam antibiotics, are of widespread occurrence in Bacteria and are related to the metabolism of bacterial cell wall murein. So far, no information exists on β-lactamases in Archaea, a separate domain of prokaryotes with diverse types of unique cell wall polymers. Different mesophilic methanogenic and extremely halophilic Archaea containing methanochondroitin, pseudomurein, or S-layer protein or glycoprotein cell walls, were tested for β-lactamase activity with the chromogenic β-lactam nitrocefin as substrate. Also tested were representative microbial Eucarya from algae, yeasts, and protozoa. No β-lactamase activity was detected in any of the archaeal and eukaryotic organisms. This supports the view that β-lactamases are restricted to the domain of Bacteria.