1. Isolation of Mn(II)-oxidizing Bacteria HMC 2010 short presentation Maren Emmerich

2. Mn 2 nd most abundant transition metal in Earth‘s crust Mn redox cycling environmentally important Mystery of microbial Mn 2+ oxidation: Not used for energy metabolism, why else? 3 models of Mn 2+ -oxidizing bacteria: - outer-membrane-associated multicopper-oxidases in Leptothrix discophora & 2 Pseudomonas putida strains - multicopper oxidase in marine Bacillus spores - marine  -proteobacteria Why? How? Results Ideas

3. Mn 2 nd most abundant transition metal in Earth‘s crust Mn redox cycling environmentally important Mystery of microbial Mn 2+ oxidation: Not used for energy metabolism, why else? 3 models of Mn 2+ -oxidizing bacteria: - outer-membrane-associated multicopper-oxidases in Leptothrix discophora & 2 Pseudomonas putida strains - multicopper oxidase in marine Bacillus spores - marine  -proteobacteria Mn 2+ -oxidizers found in phylogenetically diverse groups Why? How? Results Ideas

4. I) Sampling at Elkhorn Slough Why? How? Results Ideas II) Streak out 2 x 100 µl on K medium complex medium enriched with 100 µM MnCl 2 III) Aerobic incubation on labbench for 1-3 weeks…

5. Why? How? Results Ideas Restreak brown colonies

6. Why? How? Results Ideas Leucoberbelin blue test for MnO 2

7. Why? How? Results Ideas Some statistics 34 samples from Kirby Park, Strawberry Mat, HMS beach 10 plates with brown colonies after 1-3 weeks (AVG: 1.6) 4 leucoberbelin positives after restreak No isolate yet Successful sampling sites Kirby Park HMS beach

8. Why? How? Results Ideas Phylogeny of Mn 2+ -oxidizers? Sequence 16S rRNA genes of positive colonies Do isolates grow in liquid? Under which conditions? Inoculate minimal media and add different electron donors & acceptors, incubate +/- light… Energetical benefit of Mn 2+ oxidation? Compare growth yields of isolates grown +/- manganese More ideas? GGggggGg GGggggGg

9. Thank you!

10. 2H + + 2e - H 2 -0.42 NAD + + 2H + + 2e - NADH + H + -0.32 S + 2H + + 2e - H 2 S -0.274 SO 4 -2 + 8H + + 8e - H 2 S -0.22 pyruvate + 2H + + 2e - lactate -0.185 FAD + 2H + + 2e - FADH + H + -0.18 cytochrome b (Fe 3+ ) + e - cytochrome b (Fe +2 ) 0.075 ubiquinone + 2H + + 2e - ubiquinone H2 0.10 cytochrome c (Fe +3 ) + e - cytochrome c (Fe +2 ) 0.254 NO 3 - + 2H + + 2e - NO 2 - + H 2 O 0.421 NO 2 - + 8H + + 6e - NH 4 0.44 Fe +3 + e - Fe +2 0.771 O 2 + 4H + + 4e - 2H 2 O 0.815 Why? How? Results Idea Standard redox potentials at pH = 7

11. Reaction: Mn 2+ + 0.5 O 2 + H 2 O → MnO 2 + 2H + G◦ = −80.8 kJ/mole; Mn E◦ = + 0.419 V