Genomes of ubiquitous marine and hypersaline Hydrogenovibrio, Thiomicrorhabdus and Thiomicrospira spp. encode a diversity of mechanisms to sustain chemolithoautotrophy in heterogeneous environments.

Authors: Scott, Kathleen M and Williams, John and Porter, Cody M B and Russel, Sydney and Harmer, Tara L and Paul, John H and Antonen, Kirsten M and Bridges, Megan K and Camper, Gary J and Campla, Christie K and Casella, Leila G and Chase, Eva and Conrad, James W and Cruz, Mercedez C and Dunlap, Darren S and Duran, Laura and Fahsbender, Elizabeth M and Goldsmith, Dawn B and Keeley, Ryan F and Kondoff, Matthew R and Kussy, Breanna I and Lane, Marannda K and Lawler, Stephanie and Leigh, Brittany A and Lewis, Courtney and Lostal, Lygia M and Marking, Devon and Mancera, Paola A and McClenthan, Evan C and McIntyre, Emily A and Mine, Jessica A and Modi, Swapnil and Moore, Brittney D and Morgan, William A and Nelson, Kaleigh M and Nguyen, Kimmy N and Ogburn, Nicholas and Parrino, David G and Pedapudi, Anangamanjari D and Pelham, Rebecca P and Preece, Amanda M and Rampersad, Elizabeth A and Richardson, Jason C and Rodgers, Christina M and Schaffer, Brent L and Sheridan, Nancy E and Solone, Michael R and Staley, Zachery R and Tabuchi, Maki and Waide, Ramond J and Wanjugi, Pauline W and Young, Suzanne and Clum, Alicia and Daum, Chris and Huntemann, Marcel and Ivanova, Natalia and Kyrpides, Nikos and Mikhailova, Natalia and Palaniappan, Krishnaveni and Pillay, Manoj and Reddy, T B K and Shapiro, Nicole and Stamatis, Dimitrios and Varghese, Neha and Woyke, Tanja and Boden, Rich and Freyermuth, Sharyn K and Kerfeld, Cheryl A

Chemolithoautotrophic bacteria from the genera Hydrogenovibrio, Thiomicrorhabdus and Thiomicrospira are common, sometimes dominant, isolates from sulfidic habitats including hydrothermal vents, soda and salt lakes and marine sediments. Their genome sequences confirm their membership in a deeply branching clade of the Gammaproteobacteria. Several adaptations to heterogeneous habitats are apparent. Their genomes include large numbers of genes for sensing and responding to their environment (EAL- and GGDEF-domain proteins and methyl-accepting chemotaxis proteins) despite their small sizes (2.1-3.1 Mbp). An array of sulfur-oxidizing complexes are encoded, likely to facilitate these organisms' use of multiple forms of reduced sulfur as electron donors. Hydrogenase genes are present in some taxa, including group 1d and 2b hydrogenases in Hydrogenovibrio marinus and H. thermophilus MA2-6, acquired via horizontal gene transfer. In addition to high-affinity cbb3 cytochrome c oxidase, some also encode cytochrome bd-type quinol oxidase or ba3 -type cytochrome c oxidase, which could facilitate growth under different oxygen tensions, or maintain redox balance. Carboxysome operons are present in most, with genes downstream encoding transporters from four evolutionarily distinct families, which may act with the carboxysomes to form CO2 concentrating mechanisms. These adaptations to habitat variability likely contribute to the cosmopolitan distribution of these organisms.© 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

Journal: Environmental microbiology
DOI: 10.1111/1462-2920.14090
Year: 2018

Read publication