Ecological and Evolutionary Science
Research Article | Ecological and Evolutionary ScienceChlamydomonas reinhardtii LFO1 Is an IsdG Family Heme OxygenaseThis work establishes a protein in the freshwater alga Chlamydomonas reinhardtii as an IsdG family heme oxygenase. This protein, LFO1, exhibits predicted secondary structure and catalytic residues conserved in IsdG family members, in addition to a chloroplast localization sequence. Additionally, the catabolite that results from the degradation of heme by LFO1 is...
Research Article | Ecological and Evolutionary ScienceHiding in Plain Sight: Mining Bacterial Species Records for Phenotypic Trait InformationCultivation in the laboratory is key for understanding the phenotypic characteristics, growth requirements, metabolism, and environmental preferences of bacteria. However, oftentimes, phenotypic information is not easily accessible. Here, we compiled phenotypic and environmental tolerance information for >5,000 bacterial strains described in the International Journal of Systematic and Evolutionary Microbiology (IJSEM). We...
Research Article | Ecological and Evolutionary ScienceEvolution of Cost-Free Resistance under Fluctuating Drug Selection in Pseudomonas aeruginosaAntibiotic resistance is a global problem that greatly impacts human health. How resistance persists, even in the absence of antibiotic treatment, is thus a public health problem of utmost importance. In this study, we explored the antibiotic treatment conditions under which cost-free resistance arises, using experimental evolution of the bacterium Pseudomonas aeruginosa...
Research Article | Ecological and Evolutionary ScienceBehavioral Effects of a Chemorepellent Receptor Knockout Mutation in Tetrahymena thermophilaAlthough many single-cell eukaryotes have served as classical model systems for chemosensory studies for decades, the major emphasis has been on chemoattraction and no chemorepellent receptor gene has been identified in any unicellular eukaryote. This is the first description of a gene that codes for a chemorepellent receptor in any protozoan. Integration of both depolarizing chemorepellent pathways and hyperpolarizing chemoattractant...
Research Article | Ecological and Evolutionary ScienceBacterial Community Composition and Dynamics Spanning Five Years in Freshwater Bog LakesLakes are excellent systems for investigating bacterial community dynamics because they have clear boundaries and strong environmental gradients. The results of our research demonstrate that bacterial community composition varies by year, a finding which likely applies to other ecosystems and has implications for study design and interpretation. Understanding the drivers and controls of bacterial communities on long time scales would...
Research Article | Ecological and Evolutionary ScienceFine-Scale Structure Analysis Shows Epidemic Patterns of Clonal Complex 95, a Cosmopolitan Escherichia coli Lineage Responsible for Extraintestinal InfectionEscherichia coli clonal complex 95 represents a cosmopolitan, genetically diverse lineage, and the extensive substructure observed in this lineage is epidemiologically and clinically relevant. The frequency with which CC95 strains are responsible for extraintestinal infection appears to have been stable over the past 15 years. However, the different subgroups...
Research Article | Ecological and Evolutionary ScienceLake Bacterial Assemblage Composition Is Sensitive to Biological Disturbance Caused by an Invasive Filter FeederFreshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a variety of these disturbances. Yet, relatively few studies have focused on how species invasion, which is one of the most important aspects of anthropogenic global change, affects...
Research Article | Ecological and Evolutionary ScienceGenomewide Mutational Diversity in Escherichia coli Population Evolving in Prolonged Stationary PhaseProlonged stationary phase in bacteria, contrary to its name, is highly dynamic, with extreme nutrient limitation as a predominant stress. Stationary-phase cultures adapt by rapidly selecting a mutation(s) that confers a growth advantage in stationary phase (GASP). The phenotypic diversity of starving E. coli populations has been studied in detail; however, only a few...
Research Article | Ecological and Evolutionary SciencepH-Mediated Microbial and Metabolic Interactions in Fecal Enrichment CulturesThe human gut is a dynamic environment in which microorganisms consistently interact with the host via their metabolic products. Some of the most important microbial metabolic products are fermentation products such as short-chain fatty acids. Production of these fermentation products and the prevalence of fermenting microbiota depend on pH, alkalinity, and available dietary sugars, but details about their metabolic interactions are...
Research Article | Ecological and Evolutionary SciencePhylogenomic Reconstruction of the Oomycete Phylogeny Derived from 37 GenomesThe oomycetes are a class of eukaryotes and include ecologically significant animal and plant pathogens. Single-gene and multigene phylogenetic studies of individual oomycete genera and of members of the larger classes have resulted in conflicting conclusions concerning interspecies relationships among these species, particularly for the Phytophthora genus. The onset of next-generation sequencing techniques now means that a...