Colwellia psychrerythraea Strains from Distant Deep Sea Basins Show Adaptation to Local Conditions

Abstract

Many studies have shown that microbes, which share nearly identical 16S rRNA genes, can have highly divergent genomes. Microbes from distinct parts of the ocean also exhibit biogeographic patterning. Here we seek to better understand how certain microbes from the same species have adapted for growth under local conditions. The phenotypic and genomic heterogeneity of three strains of Colwellia psychrerythraea was investigated in order to understand adaptions to local environments. Colwellia are psychrophilic heterotrophic marine bacteria ubiquitous in cold marine ecosystems. We have recently isolated two Colwellia strains: ND2E from the Eastern Mediterranean and GAB14E from the Great Australian Bight. The 16S rRNA sequence of these two strains were greater than 98.2% identical to the well-characterized C. psychrerythraea 34H, which was isolated from arctic sediments. Salt tolerance, and carbon source utilization profiles for these strains were determined using Biolog Phenotype MicoArrays. These strains exhibited distinct salt tolerance, which was not associated with the salinity of sites of isolation. The carbon source utilization profiles were distinct with less than half of the tested carbon sources being metabolized by all three strains. Whole genome sequencing revealed that the genomes of these three strains were quite diverse with some genomes having up to 1600 strain-specific genes. Many genes involved in degrading strain-specific carbon sources were identified. There appears to be a link between carbon source utilization and location of isolation with distinctions observed between the Colwellia isolate recovered from sediment compared to water column isolates.

Model metabolic strategy for heterotrophic bacteria in the cold ocean based on Colwellia psychrerythraea 34H

“…A stock culture of 34H was inoculated into half-organic-strength marine broth medium. Cells were grown to an OD 600 of 0.40 and then inoculated at a ratio of 0.5 vol/vol% into ASW medium containing the appropriate 13 C carbon substrates ([1-13 C] glucose, [1,[2][3][4][5][6][7][8][9][10][11][12][13] C] glucose, [U-13 C] glucose, [U-13 C] glucose, unlabeled glyoxalate, unlabeled glucose, [1,[2][3][4][5][6][7][8][9][10][11][12][13] C] acetate, or [3-13 C] lactate). Cells were subcultured in the same medium at an inoculation ratio of 0.5 vol/vol% to minimize carryover of unlabeled carbon.…”

“…In this study, Colwellia psychrerythraea 34H (henceforth, 34H), a psychrophilic extremophile (unable to grow above 18°C) of ecological importance in the cold ocean, was used as a model species for investigating the metabolism of cold-adapted microbial life. This Gram-negative, heterotrophic gammaproteobacterium, originally isolated from arctic marine sediments (10), is considered cosmopolitan to polar regions and the cold deep sea (11,12). Although ice adapted in many ways (11), 34H also represents the cold dark ocean in its lack of proteorhodopsins, photoactive proteins used by many bacteria in the surface ocean to generate supplemental energy (13).…”

“…Genomic studies of 34H and other strains of C. psychrerythraea have revealed many metabolic pathways that are important in the geochemical cycling of nutrients in cold marine environments (14), including those for hydrocarbon degradation and denitrification (14,15). For example, an amplified genome of C. psychrerythraea, present in the Colwellia-rich microbial community that responded at depth to the Deepwater Horizon oil spill (12,16,17), has the potential to degrade ethane and propane (components of natural gas), suggesting a possible role in bioremediation of cold environments. Additionally, 34H has the capacity to produce industrially relevant compounds, such as polyhdyroxyalkanoate and polyamides (14) and unique cryoprotectants (18).…”

“…12 C-and 13 C-fingerprinting experiments with 34H revealing its ability to incorporate CO 2 into TCA cycle metabolites, bypass the lower half of the TCA cycle (glyoxylate shunt), and utilize multiple substrates simultaneously (no glucose catabolic repression). (A) Labeling profiles of amino acids derived from OAA in cultures grown with U-13 C glucose.…”

A controlled aquarium system and approach to study the role of sponge-bacteria interactions using Aplysilla rosea and Vibrio natriegens

“…At both time points, Colwellia was one of the major genera found in the treated sponges. Colwellia species have their own characteristics and functions in relation to their role in interacting with sponges 58 , however, the reason for the abundance of these genera in the present study require further investigation. Vibrionales of the Proteobacteria, such as Pseudoalteromonas and Vibrio , have been recognised as the governing antibiotics producers 59 , 60 .…”