- Dona Paula, Goa, India.
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| Abstract Submission No. | ABS-2022-06-0325 |
| Title of Abstract | Distribution and diversity of Carbon Monoxide Dehydrogenases in Marine Microorganisms |
| Authors | Nipa Chongdar*, Samir R. Damare |
| Organisation | CSIR-National Institute of Oceanography |
| Address | Raj Bhavan Rd, Dona Paula Panaji, Goa, India Pincode: 403004 Mobile: 9903857308 E-mail: chongdar.nipa@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Carbon monoxide (CO) is a trace gas, mostly known for its toxicity. Globally, ⿿ 1000 teragrams CO is produced annually by anthropogenic and natural processes. Microbial consumption of CO is one of the main ways to remove this toxic gas from the atmosphere. Both soil and ocean are considered to be important sinks of CO due to microbial consumption. Experimental studies to date have identified microbial CO-metabolizers from a few regions of the sea, but the scope of CO-metabolism in the entire marine biota remains uncertain. In this work, we have performed a database survey to identify marine CO-metabolizers. The CO metabolizing microbes use enzymes called carbon monoxide dehydrogenase (CODH) to oxidize CO to CO2. The CODHs are classified into two distinct groups: the nickel-containing CODHs (Ni-CODH) and molybdenum-copper containing CODHs (MoCu-CODH), depending on the metal content in the active centre. While Ni-CODHs are oxygen-sensitive, the MoCu-CODHs are oxygen tolerant. Our analysis identified 167-anaerobic, and 328-aerobic CO-utilizing species distributed in the various ocean zones. Compared to MoCu-CODHs (identified in species from five bacterial and one archaeal phylum), Ni-CODHs are spread over a broader range of marine prokaryotes (found in species from 10 bacterial and one archaeal phylum). Interestingly, while CODH expressing organisms are dispersed across the entire oceanic zones and the seafloor sediments, distinct differences are observed between the habitats of Ni-CODH and MoCu-CODH containing species. The Ni-CODHs expressing species are prevalent in hydrothermal vents and marine sediments, whereas MoCu-CODH containing organisms are more frequent in the coastal environments (including mangrove soil). Usually, the Ni-CODHs are encoded by anaerobes, while MoCu-CODHs are expressed in aerobes. Therefore, it is likely that the distribution of these species across different oceanic layers is regulated by the dissolved oxygen concentration in the seawater. Overall, this work provides a comprehensive overview of the extent of CO-metabolism in the marine ecosphere to understand the scope and influence of CO-metabolism on the ocean ecosystem. |