Patterns of Prokaryotic Activities and Abundance among the Epi-Meso and Bathypelagic Zones of the Southern-Central Tyrrhenian Sea

Prokaryotes (including Bacteria and Archaea) are an important component of the planktonic community of aquatic ecosystems and a critical link in the microbial loop, playing a vital role in nutrient cycling and food-web structure within the marine environment. Particularly, heterotrophic microorganisms (bacteria, fungi) are the main consumers of Dissolved Organic Matter (DOM) and therefore they are the major players in organic matter turnover within the “microbial loop”. 

Thanks to their wide biodiversity and their large variety of metabolic activities, microorganisms contribute significantly to the regulation of the flux of organic matter and energy from the biotic to abiotic compartments, acting in both decomposition (by DOM hydrolysis and nutrient release) and production processes (new living biomass production). Enzymatic hydrolysis of organic matter, which is mostly composed of both dissolved and particulate polymers, is recognized as a critical process and a “bottleneck” for organic matter utilization. In fact, heterotrophic microorganisms may uptake directly only low molecular weight substrates, such as aminoacids, simple sugars, fatty acids.  Read more..............