The secret role of sulfate-reducing bacteria in marine conservation!

The secret role of sulfate-reducing bacteria in marine conservation!

A new study published in the journal Science Advances examines the critical role of sulfate-reducing bacteria (SRB) in the breakdown of organic matter in the seafloor. The research work was carried out by Dr. Lars Wöhlbrand and Prof. Dr. Ralf Rabus from the University of Oldenburg led. These microbes, particularly the Desulfobacteraceae family, are active in oxygen-free zones of the Earth and contribute significantly to the production of carbon dioxide (CO2).

The Desulfobacteraceae have a modular metabolism that allows them to utilize a variety of organic molecules. In the study, six different strains of these bacteria were cultured and extensively tested. The microbes were given 35 different foods and examined under 80 specific conditions. The results show that the different types of metabolism use similar molecular tools for degradation. This explains the globally distributed and flexible nature of Desulfobacteraceae.

Role of bacteria in the carbon cycle

It is estimated that sulfate-reducing bacteria account for more than half of the degradation of organic material in coastal waters and shelf areas. Their activity leads to the formation of hydrogen sulfide and black iron sulfide in the sediment. Despite their importance, the role of Desulfobacteraceae in the carbon cycle is often underestimated. The genetic markers of certain key modules have been detected in sediment samples obtained from various marine habitats.

One particularly notable strain, Desulfococcus multivorans, has a complete genome consisting of a single, circular chromosome of 4,455,399 base pairs. This ranges in size from other SRBs such as Desulfotalea psychrophila to Desulfobacterium autotrophicum HRM2. The genomic analysis has identified not only genes for tRNA and rRNA, but also numerous genes associated with the economic diversity and adaptability of these bacteria.

Metabolic flexibility

The study highlights that SRBs can convert not only sulfate, but also a variety of organic compounds that are difficult to degrade. Metabolic reconstruction of D. multivorans shows that these bacteria are capable of degrading aromatic and aliphatic substrates, which are oxidized to CO2 via the Wood-Ljungdahl pathway. They use a variety of enzymes that are required for β-oxidation and respond adaptively to oxygen stress.

The diversity of enzymes and the high coverage of the proteome analyzes indicate a robust metabolic capacity that these bacteria are able to develop. These results can play a crucial role in understanding the impacts of climate change on marine ecosystems. With decreasing oxygen levels in the oceans, the importance of SRB in breaking down organic matter could further increase.

This research not only provides new insights into the biological processes that support carbon cycling, but also opens perspectives for future studies that seek to understand microbial metabolism at the genetic level. The Desulfobacteraceae are not only in focus as key factors in carbon degradation, but also impressively demonstrate the plasticity and adaptability of microbial life in complex ecosystems.

The comprehensive studies on the distribution, metabolic processes and ecological significance of Desulfobacteraceae contribute to deepening our understanding of carbon dynamics and their interactions with ocean chemistry. The insights gained from this study could have far-reaching implications for understanding marine microbial ecology and the global carbon cycle.

uol.de reports that… and PMC explains basic genetic aspects... and sigmaearth expands the context on the role of SRB...