Recovery and characterization of a 30.7-kDa protein from Bacillus licheniformis associated with inhibitory activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and Listeria monocytogenes.

摘要

A total of 131 bacterial isolates were obtained from seaweed. Among them, a culture of Bacillus licheniformis was found to produce a novel protein with antibacterial activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and Listeria monocytogenes. The antibacterial activity was maximal in cultures prepared in Columbia broth containing pieces of synthetic polyurethane sponge and shaken at 210-230 rpm. Antibacterial activity was not found in cultures grown statically or with different speeds of rotary shaking. Reduced activity was apparent in supernatants prepared from marine 2216E broth and tryptone soya broth with or without 1% (w/v) NaCl. The antibacterial compound was sensitive to proteinase K, pronase and trypsin, but was not affected by Tween-20, -40, -60 or -80, or by alpha- or beta-amylase. Activity was not adversely affected by heating up to 40 degrees C or treatment at pH 5-14. The bioactive compound was determined to be associated with a protein of 30.7 kDa, which had homology to the YbdN protein of B. licheniformis ATCC 14580.