Transcript Growth and morphological variation in microorganisms exposed to

Growth and Morphological
Variation in Microorganisms
Exposed to Lead
JOE TONEY*, DANIELLE DAY, JENNIFER
SEABAUGH, ANDREW CORCORAN,
JENNIFER ARNOLD, and JAMES E.
CHAMPINE
Southeast Missouri State University
Lead Mining in Missouri
• Lead-belt region
(Mineral Area
College)
• Chat: mine tailings
covering acres of land
• Hypothesis: Natural
enrichment for leadresistant
microorganisms
Lead Content, ppm, of Soil and Chat
Fraction
Total
Bioavailable
Total
Isolates
Sample 12
Soil
2,725
Sample 14
Chat
16,733
Sample 15
Soil
1,289
4,023
16,733
2,294
Pb4, Pb5
CPA 1,2,6
CPC 2,3,4,5
Pb1, Pb3
Approach
• Bacteria were eluted from
chat and applied to the
surface of agar plates.
• Defined chemical media
containing lead called
“Roane Media”
• This media is formulated
to minimize precipitation
of lead.
• Equation
– [Pb]sol = 0.045[Pb]tot-0.12
mM
My Isolates
CPC3
CPC2
TSA
RM
1mM
CPC4
RM
RM
2.5mM
CPC5
CPC5=CPA6=Pb5
Rhodococcus fascians (luteus)
CPC3=CPA1
No Lead
Lead
• Gram positive species
not in the MIDI
database
• Microbacterium
(Corynebacterium)
laevinformans
Serratia marcescens
No Lead
Lead
Enterobacter
No Lead
Lead
Pb3O4
PbO2
PbO
Gradient Plates
Gradient
Safranin
Discontinuous
Gradient
Crystal
Violet
CPC5
5 mM
Pb
No
Growth
0 mM
Pb
Reasons for Color Variation
• Secondary
Metabolism
– Pigments produced in
response to stress
– Serratia marcescens
– Test by pigment
extraction procedures
• Precipitation of Pb
– Found in Fungal
Isolate Pb3
– Coloration resembles
Lead Oxides and/or
Phosphate
– Test by Electron
Microscopy and
Electron Diffraction
Studies
Acknowledgements
• Coauthors
– Jennifer Seabaugh
– Danielle Day
– James Collins
• Jennifer Arnold,
Andrew Corcoran
• Maija Bluma
• Funding from SEMO
Undergraduate
Research Program