Volume 16 of Advances in Microbial Ecology has a difficult history. Nearly halfway through its completion, Gwynfryn Jones had to resign as managing edi­ tor for health reasons, and he asked me to take over. I want to thank Gwyn for his dedicated work in this publication series, and wish him all the best for the future. After the change in editorship, some authors had to be encouraged on rather short notice to provide their chapters in order to make appearance of this volume possible within a reasonable period of time. Nonetheless, I think that the articles we present with this volume represent an enjoyable collection of up-to-date con­ tributions to microbial ecology. In my own understanding, microbial ecology com­ prises the elucidation of microbial activities in natural or semi natural environ­ ments, including physiology, biochemistry, population dynamics, and interactions with all the biotic and abiotic environmental conditions microbes encounter. This comprises studies on single organisms in defined cultures in an ecological per­ spective, the analysis of microbial activities in complex environments, as well as the development of concepts for the interactions of microorganisms with the world in which they live. Last but not least, microbial ecology is not an exotic science studied exclusively in remote places untouched by human beings.

1 Achromatium oxaliferum: Understanding the Unmistakable.- 1. Historical Introduction.- 2. Phylogeny of A. oxaliferum.- 3. Morphology and Ultrastructure.- 4. The Habitat of A. oxaliferum.- 5. Physiology and Biogeochemical Role.- 6. Conclusions.- References.- 2 Bacterial Manganese and Iron Reduction in Aquatic Sediments.- 1. Introduction.- 2. Iron and Manganese in Aquatic Sediments.- 3. Manganese- and Iron-Reducing Microorganisms in Culture.- 4. Microbial Manganese and Iron Reduction in Sediments.- 5. Summary.- References.- 3 Plant-Associated Methane Oxidation in Rice Fields and Wetlands.- 1. Introduction.- 2. The Global Balance: Methanogenesis and Methanotrophy.- 3. The Environment: Flooded Soils and Wetland Plants.- 4. Methane Oxidation: Organisms, Physiology, and Activities.- 5. Conclusion.- References.- 4 Heterotrophic, Planktonic Bacteria and Cycling of Phosphorus Requirements, Competitive Ability, and Food Web Interactions.- 1. Introduction.- 2. Models for Predicting Growth Rate and Competitive Ability of Phosphorus-Limited Planktonic Bacteria.- 3. Kinetic Characterization of Heterotrophic Bacteria.- 4. Comparison of the Competitive Ability of Heterotrophic Bacteria, Planktonic Algae Cyanobacteria.- 5. The Role of Heterotrophic Planktonic Bacteria in Phosphorus Cycling in the Photic Zone of Lakes.- 6. Conclusions.- References.- 5 Ecological Aspects of Biological Phosphorus Removal in Activated Sludge Systems.- 1. Introduction.- 2. Functions of Poly-P.- 3. Biosynthesis and Degradation of Poly-P.- 4. Phosphate Transport in Acinetobacter johnsonii 210A.- 5. Biological Phosphorus Removal.- 6. Summary and Outlook.- References.- 6 Effect of Chirality on the Microbial Degradation and the Environmental Fate of Chiral Pollutants.- 1. Introduction.- 2. Historical Background.- 3. Biological Macromolecules of Homochiral Monomers.- 4. Chirality and Biological Activity.- 5. Microbial Degradation and Environmental Fate of Chiral Pollutants ....- 6. Conclusion.- References.- 7 Complex Adaptive Systems Ecology.- 1. Introduction.- 2. SCIO Revisited.- 3. Physiology.- 4. Ecology.- 5. Evolution.- 6. CASE and the Evolutionary Dynamics.- References.