1. Preface to special section

   • D. G. Capone
   • J. P. Zehr

   EditorialNotes Pages: 229 - 230

2. Carbon cycling: Molecular regulation of photosynthetic carbon fixation

   • J. H. Paul

   OriginalPaper Pages: 231 - 245

3. Nitrification and denitrification: Probing the nitrogen cycle in aquatic environments

   • B. B. Ward

   OriginalPaper Pages: 247 - 261

4. Problems and promises of assaying the genetic potential for nitrogen fixation in the marine environment

   • J. P. Zehr
   • D. G. Capone

   OriginalPaper Pages: 263 - 281

5. S cycling: Characterization of natural communities of sulfate-reducing bacteria by 165 rRNA sequence comparisons

   • R. Devereux
   • M. E. Hines
   • D. A. Stahl

   OriginalPaper Pages: 283 - 292

6. Detection of the merA gene and its expression in the environment

   • W. H. Jeffrey
   • S. Nazaret
   • T. Barkay

   OriginalPaper Pages: 293 - 303

7. Viability and metabolic features of bacteria indigenous to a contaminated deep aquifer

   • C. M. McCarthy
   • L. Murray

   OriginalPaper Pages: 305 - 321

8. Horizontal and vertical migration patterns of Phorrnidium corallyticum and Beggiatoa spp. associated with black-band disease of corals

   • L. L. Richardson

   OriginalPaper Pages: 323 - 335