Microbial synthesis of macroparticulate matter

From a re-examination of the role of microorganisms in de novo particle synthesis in sea water, I present evidence that presence of active bacteria is necessary for aggregate formation. Particle formation, in filtered sea water kept idle, circulated and bubbled (without or with additional Dissolved Organic Matter or Dissolved Organic Matter + Particulate Organic Matter), was found to occur only in the presence of bacteria. Bacteria growing at the expense of DOM present, formed large particles > 100 microns by aggregation (bacterial aggregates) as well as by the aggregation of smaller particles into larger ones (bacteria-particle aggregates) > 1 mm. Parallel killed treatments did not show any particle formation of the type of This phenomenon of microbial macroparticulate matter synthesis could be the major pathway by which carbon and energy is transferred from the micro to the macro food webs in aquatic ecosystems.