TABLE 3.

Attachment of differently grown cells of T. ferrooxidans to various substrata^a

Substratum	Cells grown with:
	Iron(II) sulfate	Pyrite	Sulfur
Pyriteb	++	++	−
Sulfurb	−	+	++
Cation exchangerb	++	++	−
Anion exchangerc	−	−	−
Hydrophobic adsorberb	−	+	++

^aThe attachment of T. ferrooxidans cells (10⁸ cells/assay) to natural (pyrite and sulfur) and artificial substrata (ion-exchange resins and hydrophobic adsorbent resin) was assayed. ++, strong attachment (80 to 95% of inoculated cells attached to mineral); +, weak attachment (25 to 35%); −, no attachment (0%). 

^bTested at pH 2. 

^cTested at pH 7.