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 Pb 4, Pb 5 CPA 1, 2, 6 CPC 2, 3, 4, 5 Pb 1, Pb 3

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 m. M

My Isolates CPC 2 TSA RM 1 m. M CPC 4 CPC 3 RM RM 2. 5 m. M CPC 5

CPC 5=CPA 6=Pb 5 Rhodococcus fascians (luteus)

CPC 3=CPA 1 No Lead • Gram positive species not in the MIDI database • Microbacterium (Corynebacterium) laevinformans

Serratia marcescens No Lead

Enterobacter No Lead Pb 3 O 4 Pb. O 2 Pb. O

Gradient Plates Gradient Safranin Discontinuous Gradient Crystal Violet

CPC 5 5 m. M Pb No Growth 0 m. M 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 Pb 3 – 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