eudomonasaeruginosawereexaminedasrepresentativesofcommonspeciesfrequentlyisolatedfromsoils.E.coliwasalsousedasasecondgram-negativebacteriumbecauseitisawell-characterizedmicroorganismanditscellenvelopehasbeenshowntobindlessmetalthandoB.subtiliscellwalls().ThefourmetallicionsusedinthisinvestigationwereAg+,Cd+,Cu+,andLa+.Cadmiumandcopperarebothtoxiccationsofenvironmentalimportance.Silverandlanthanum,representativeofmonovalentandtrivalentheavymetals,respectively,arealsotoxicbutarelessfrequentlyfoundintheenvironment.MATERIALSANDMETHODSBacteriaandgrowthconditions.ThebacteriausedintheseexperimentswereB.cereusATCC;P.aeruginosaATCC,bothobtainedfromtheAmericanTypeCultureCollection;B.subtilis;andE.coliK-strainAB,bothfromtheUniversityofGuelph.Thebacteriawereroutinelyculturedin.xbrainheartid+都不能提供足够电子散射肯定确定沉积部位。