Overcoming Iron Stress: Genome Analyses of Marine Bacteria

• Main Author: McDermith, Emily
• Format: Text
• Language: unknown
• Published: DigitalCommons@URI 2020
• Subjects: bionformatics; genome; siderophore; Bioinformatics; Environmental Microbiology and Microbial Ecology; Marine Biology; North Atlantic; Southern Ocean
• Online Access: https://digitalcommons.uri.edu/srhonorsprog/854; https://digitalcommons.uri.edu/context/srhonorsprog/article/1869/type/native/viewcontent/McDermith_Poster.jpg

In the world’s oceans, some of the most important interactions between organisms occur on the microscopic scale. These tiny players include bacteria and phytoplankton, two groups that cohabitate in marine environments. There is evidence bacteria and phytoplankton work together in order to cope with nutrient limitation in the ocean. This study focuses on understanding these mutualisms in low iron environments. Iron is an essential micronutrient for nearly all life as it’s used in a variety of biological processes such as respiration and photosynthesis. In low iron waters, bacteria produce siderophore compounds that bind to biologically unusable forms of iron, making them into a bioavailable form. In this proposed mutualistic interaction, phytoplankton are able to take up the siderophore-bound iron and in return release carbon for bacterial growth. In this study we isolated siderophore-producing bacteria associated with phytoplankton from the Southern Ocean and the North Atlantic Ocean, two environments where bioavailable forms of iron are chronically low. We investigated their biochemical pathways of siderophore production through genome sequencing of Colwellia maris, Moritella dasanensis, Pseudoalteromonas distincta, Psychrobacter nivimaris and Salegentibacter sp. Genomes were assembled and analyzed using FeGenie, a bioinformatics tool that identified iron-related genes. Genes involved in the production of the siderophore compounds vanchrobactin, pyochelin, rhizobactin and vibrioferrin were found in two of the Southern Ocean bacteria. However, siderophore transport genes were identified in all 5 bacteria. Our findings suggest that we have potentially identified novel siderophore-producing genes in these organisms and that all these organisms have potential to utilize siderophores synthesized by nearby organisms. Identification of genes involved in siderophore production and transport will further our understanding of how organisms adapt to low iron environments. Understanding these low nutrient environments ...