High-throughput metal susceptibility testing of microbial biofilms

BMC Microbiology

Table 4 Potential neutralizing agents for the microbiological application of inactivating metals cations and oxyanions*

Metal(loid)	Neutralizing agent	Maximum concentration¹	Reference(s)
All oxyanions²	Glutathione	10 mM	[10, 18, 24]
Al³⁺, Mn²⁺	Crushed acetylsalicylic acid (ASA)	~1–2 mM³	[30, 31]
Hg²⁺, Cd²⁺	Glutathione	10 mM	[10]
	L-cysteine	10 mM	[16]
Cu²⁺, Ni²⁺	Diethyldithiocarbamic acid³ (DDTC)	2.5 mM (E. coli) up to 5 mM (P. aeruginosa)	[27]
Sn²⁺	Glycine	10 mM	[28]
Ag⁺	Sodium citrate	10 mM	[10]
Zn²⁺, Co²⁺, Pb²⁺	Glutathione	10 mM	[3]

*This is the first part of a two-part strategy to reduce the in vitro toxicity of metals (see text for details)
¹ The maximum concentration tested and employed in studies by our laboratories using the high-throughput metal susceptibility testing method presented in this paper.
² Tested heavy metal and metalloid oxyanions from our laboratories include TeO₃^2-, TeO₄^2-, SeO₃^2-, CrO₄^2-, AsO₄^3-, AsO₂^-, WO₄^2- and MoO₄^2-.
³ Application is limited by the low solubility of salicylic acid and its acetylated derivatives in water.
⁴ The maximum concentration listed is inhibitory to bacterial growth in broth culture. Recovery broth media must be spot plated onto agar to allow bacterial growth and determination of accurate MBC and MBEC values.

ISSN: 1471-2180