• metal tolerance;
  • biofilm;
  • quorum sensing;
  • Acinetobacter junii


Acinetobacter junii strain BB1A, a novel metal-tolerant bacterium, produced biofilm in the presence of added ions such as Ni2+, AsO2, Cd2+ and Hg2+ on surfaces such as glass and polystyrene. Generation of a metal-sensitive and adhesion-deficient mutant by transposition of Tn5-mob in the A. junii genome has putatively confirmed the association of metal tolerance with the production of biofilm. The requirement of a critical cell density for biofilm formation and presence of acyl-homoserine lactone-like autoinducer molecules in the cell-free supernatant indicated the phenomenon of quorum sensing. Addition of a natural quorum-sensing inhibitor (garlic extract) or synthetic quorum-sensing inhibitor (4-nitro-pyridine oxide) significantly inhibited cell growth and biofilm formation in the presence of metal/metalloid ions.