New Research Reveals the Role of Black Carbon in Microbial Activity and Interactions in Marine Environments

A new study published in Environmental Science and Pollution Research reveals the role of black carbon (BC) in shaping microbial activities and interactions in marine environments. This has significant implications for the global carbon cycle and ecosystem functioning. The research, led by Professor Francesca Malfatti from the University of Trieste, also involved the Section of Oceanography of the OGS, with researchers Amira Saidi and Mauro Celussi.

Black carbon is a byproduct of incomplete combustion of fossil fuels, biomass, and biofuels, and reaches the ocean through atmospheric deposition and river runoff. Being a key component of atmospheric particulate matter it plays an important role in the processes that lead to global warming.

Through a series of experiments set in the Adriatic Sea and in the Ligurian Sea, the researchers discovered that adding BC to the water at high concentrations (24 mg L−1) stimulates the increase of heterotrophic prokaryotes and carbon production, while reducing the presence of viruses and degradative enzymatic activities. Overall, BC amendment showed an effect on the composition of the microbial community.

These results specifically suggest that black carbon particles create distinct micro-niches in the marine environment that favour the growth of microorganisms with specific metabolic capabilities.

A better understanding of the ecological implications of black carbon deposition is crucial for refining models that describe the global carbon cycle and the mechanisms of the “microbial carbon pump” (MCP), both of which are influenced by anthropogenic BC particles. This improved understanding is also necessary to fully comprehend the contribution of anthropogenic carbon to the marine carbon cycle and to develop more effective strategies for mitigating the impacts of climate change.