INCORPORATION OF VIRUSES INTO THE BUDGET OF MICROBIAL C-TRANSFER - A 1ST APPROACH

Viral lysis of bacteria has been suggested to be a quantitatively important process in the removal of bacteria, and potentially also in the production of DOC, in the ocean. In order to investigate the quantitative role of viruses in the pelagic microbial ecosystem, a diel study was undertaken, comprising measurements of particulate and dissolved primary production, bacterial production, bacterial grazing by flagellates, bacterial lysis by viruses, and production of viruses. Estimates of algal excretion (4.7-mu-mol Cl-1 d-1)and bacterial carbon consumption (3.0-mu-mol Cl-1 d-1) estimates by a balance. Predation (2.9-mu-mol Cl-1 d-1) exceeded bacterial production (1.5-mu-mol Cl-1 d-1) estimates by a factor of 2. Major difficulties in balancing the budget emerged however, from the estimates of viral lysis of bacteria (9.2-mu-mol Cl-1 d-1), which exceeded bacterial production by a factor of 6. Despite these problems, results support the idea that viral lysis may be a quantitatively significant process that needs to be incorporated into budgets of microbial C-transfer.