chemical and mineralogical comparison of two antibacterial clays
DESCRIPTION
School of Earth & Space Exploration. Chemical and mineralogical comparison of two antibacterial clays. Amanda Turner Dr. Lynda Williams, Dr. Shelley Haydel*, Christine Remenih* & Tanya Borchardt*. ANTIBACTERIAL EFFECTIVENESS. Isolating bacteria affected by clay. - PowerPoint PPT PresentationTRANSCRIPT
Chemical and mineralogical comparison of two antibacterial
clays
Amanda Turner
Dr. Lynda Williams, Dr. Shelley Haydel*, Christine Remenih* & Tanya Borchardt*
School of Earth & Space Exploration
Investigating Antibacterial Clay Minerals
Isolating bacteria affected by clay
Isolating the antibacterial clay minerals
ANTIBACTERIAL EFFECTIVENESS
ANTIBACTERIAL MECHANISM
Testing for chemical interaction
ICP-MS, Electron Probe, pH, Eh:
Toxin provided? Nutrient depleted?
Testing for physical interaction
SEM, Mineralogy:
Clay-cell attraction? Physical disruption?
Bulk Mineralogy
NONClays Clays10.4% Qtz 44.9% Smectite6.2% Olig 16.5% Illite5.3% Alb 1.1% Gibbsite
6.7% Others
NONClays Clays39.3% Qtz 21.5% Illite3.2% Pyrite 16.2% Smectite1.2% Barite 4.1% Kaol.1.0% Magnetite 3.3% Pyroph.
Clay Mineralogy
No ONE antibacterial mineral How about the chemistry?
InterlayerSurfaces X
X
X
X
Adsorbed onto surface
20 nm thickclay laths
OR
Antibacterial clay
NV
10-20 nmamorphous
particles
graphiteAntibacterial clay
Leachate Chemistry
x x x
H2O
200C
C H O N S P F Cl Br I Hg
OR07 Kills
NV07 Kills
X X X X X
x
x
AntibacterialClay
Leachate Chemistry
x x x
H2O
200C
C H O N S P F Cl Br I Hg
550C
x x x
OH
Rb Cs Se Cd As
OR07 Kills
NV07 Kills
OR07 doesn’t kill
NV0 partially kills
X X X X X
x
x
AntibacterialClay
Leachate Chemistry
x x x
H2O
200C
C H O N S P F Cl Br I Hg
550C
x x x
OH
Rb Cs Se Cd As
900C
Elements not volatilizedFe Zn Ni Cu V Co W Cr Ag Cd Pb U
All below MICIn oxidized form!
OR Kills
NV Kills
OR doesn’t kill
NV partially killsNeither Kill!
X X X X X
x
x
AntibacterialClay
pH Eh (mV)
NV (<2.0µm) 3.96 +146
OR (<2.0µm) 3.48 +172
French clays HIGH LOW
Non-AB clays Neutral Neutral
2 µm
500 nm
5 µm
Healthy E. coli
2 µm
500 nm
After clay incubation
What We’ve Learned
X X X X X
x
x
AntibacterialClay
PHYSICAL CHEMICAL
Mineralogy
SEM pH, Eh
Leachates
No ONE mineral responsible
No visible disruption of the cell
Extreme pH, Eh values
Heating regimes may volatilize vital elements
Agents soluble at pH ~4
Illite/Smectite
Future Work
• More Imaging!• Model elemental speciation at varying pH
and Eh – similarities?• Cation exchange (xc)
- remove xc’able ions-test xc solution and xc’d clay
• Electron and Ion Microscopy - clay/bacteria interactions
Acknowledgements
Other ColleaguesDr. Dennis Eberl
Dr. Ross Giese
NCCAM
LeRoy Eyring CSSS
Dr. Shelley HaydelTanya BorchardtChristine RemeniAmanda CoteyDr. Renu SharmaDr. Karl WeissDr. Laurence GarvieDr. Gordon MooreZack BowlesDr. Panjai Prapaipong