Evolution: Spectral speciation.

Speciation is a complex process sparked by multitudes of environmental stressors and culminating in adaptive, and perhaps novel, phenotypic traits. A new study presents evidence supporting spectral niche-partitioning in a cyanobacterial clade specializing in far-red photosynthesis.

Taxonomic and functional restoration of tallgrass prairie soil microbial communities in comparison to remnant and agricultural soils.

Restoring ecosystems requires the re-establishment of diverse soil microbial communities that drive critical ecosystem functions. In grasslands, restoration and management require the application of disturbances like fire and grazing. Disturbances can shape microbial taxonomic composition and potentially functional composition as well.

Restoration age and reintroduced bison may shape soil bacterial communities in restored tallgrass prairies.

Knowledge of how habitat restoration shapes soil microbial communities often is limited despite their critical roles in ecosystem function. Soil community diversity and composition change after restoration, but the trajectory of these successional changes may be influenced by disturbances imposed for habitat management. We studied soil bacterial communities in a restored tallgrass prairie chronosequence for >6 years to document how diversity and composition changed with age, management through fire, and grazing by reintroduced bison, and in comparison to pre-restoration agricultural fields and remnant prairies.

Heterologous complementation systems verify the mosaic distribution of three distinct protoporphyrinogen IX oxidase in the cyanobacterial phylum.

The pathways for synthesizing tetrapyrroles, including heme and chlorophyll, are well-conserved among organisms, despite the divergence of several enzymes in these pathways. Protoporphyrinogen IX oxidase (PPOX), which catalyzes the last common step of the heme and chlorophyll biosynthesis pathways, is encoded by three phylogenetically-unrelated genes, hemY, hemG and hemJ. All three types of homologues are present in the cyanobacterial phylum, showing a mosaic phylogenetic distribution.

Discovery of Chlorophyll : Isolation and Characterization of a Far-Red Cyanobacterium from the Original Site of Manning and Strain (1943) at Moss Beach, California.

We have isolated a chlorophyll--containing cyanobacterium from the intertidal field site at Moss Beach, on the coast of Central California, USA, where Manning and Strain (1943) originally discovered this far-red chlorophyll. Here, we present the cyanobacterium's environmental description, culturing procedure, pigment composition, ultrastructure, and full genome sequence. Among cultures of far-red cyanobacteria obtained from red algae from the same site, this strain was an epiphyte on a brown macroalgae.

Complete genome of the thermophilic purple sulfur Bacterium Thermochromatium tepidum compared to Allochromatium vinosum and other Chromatiaceae.

The complete genome sequence of the thermophilic purple sulfur bacterium Thermochromatium tepidum strain MC (DSM 3771) is described and contrasted with that of its mesophilic relative Allochromatium vinosum strain D (DSM 180) and other Chromatiaceae. The Tch. tepidum genome is a single circular chromosome of 2,958,290 base pairs with no plasmids and is substantially smaller than the genome of Alc.

tRNA functional signatures classify plastids as late-branching cyanobacteria.

Background: Eukaryotes acquired the trait of oxygenic photosynthesis through endosymbiosis of the cyanobacterial progenitor of plastid organelles. Despite recent advances in the phylogenomics of Cyanobacteria, the phylogenetic root of plastids remains controversial. Although a single origin of plastids by endosymbiosis is broadly supported, recent phylogenomic studies are contradictory on whether plastids branch early or late within Cyanobacteria.

Genomic Comparison of Two Family-Level Groups of the Uncultivated NAG1 Archaeal Lineage from Chemically and Geographically Disparate Hot Springs.

Recent progress based on single-cell genomics and metagenomic investigations of archaea in a variety of extreme environments has led to significant advances in our understanding of the diversity, evolution, and metabolic potential of archaea, yet the vast majority of archaeal diversity remains undersampled. In this work, we coordinated single-cell genomics with metagenomics in order to construct a near-complete genome from a deeply branching uncultivated archaeal lineage sampled from Great Boiling Spring (GBS) in the U.S.

Soil microbial community composition in tallgrass prairie restorations converge with remnants across a 27-year chronosequence.

Restoration and management of natural ecosystems is a critical strategy in mitigating global biodiversity loss. This is exemplified in the American Midwest by efforts aimed at reclaiming historical grasslands lost to high-yield agriculture. While restorations traditionally take the form of plant reintroduction and management, advances in microbial analyses suggest that soil communities could be indicators restoration success.

Genome Sequence of Rhodoferax antarcticus ANT.BR; A Psychrophilic Purple Nonsulfur Bacterium from an Antarctic Microbial Mat.

is an Antarctic purple nonsulfur bacterium and the only characterized anoxygenic phototroph that grows best below 20 °C. We present here a high-quality draft genome of strain ANT.BR, isolated from an Antarctic microbial mat.

Correction: The First Complete Plastid Genome from Joinvilleaceae (J. ascendens; Poales) Shows Unique and Unpredicted Rearrangements.

[This corrects the article DOI: 10.1371/journal.pone.

The First Complete Plastid Genome from Joinvilleaceae (J. ascendens; Poales) Shows Unique and Unpredicted Rearrangements.

Joinvilleaceae is a family of tropical grass-like monocots that comprises only the genus Joinvillea. Previous studies have placed Joinvilleaceae in close phylogenetic proximity to the well-studied grass family. A full plastome sequence was determined and characterized for J.

Single-Cell-Genomics-Facilitated Read Binning of Candidate Phylum EM19 Genomes from Geothermal Spring Metagenomes.

The vast majority of microbial life remains uncatalogued due to the inability to cultivate these organisms in the laboratory. This "microbial dark matter" represents a substantial portion of the tree of life and of the populations that contribute to chemical cycling in many ecosystems. In this work, we leveraged an existing single-cell genomic data set representing the candidate bacterial phylum "Calescamantes" (EM19) to calibrate machine learning algorithms and define metagenomic bins directly from pyrosequencing reads derived from Great Boiling Spring in the U.

tRNA signatures reveal a polyphyletic origin of SAR11 strains among alphaproteobacteria.

Molecular phylogenetics and phylogenomics are subject to noise from horizontal gene transfer (HGT) and bias from convergence in macromolecular compositions. Extensive variation in size, structure and base composition of alphaproteobacterial genomes has complicated their phylogenomics, sparking controversy over the origins and closest relatives of the SAR11 strains. SAR11 are highly abundant, cosmopolitan aquatic Alphaproteobacteria with streamlined, A+T-biased genomes.

Single-cell and metagenomic analyses indicate a fermentative and saccharolytic lifestyle for members of the OP9 lineage.

OP9 is a yet-uncultivated bacterial lineage found in geothermal systems, petroleum reservoirs, anaerobic digesters and wastewater treatment facilities. Here we use single-cell and metagenome sequencing to obtain two distinct, nearly complete OP9 genomes, one constructed from single cells sorted from hot spring sediments and the other derived from binned metagenomic contigs from an in situ-enriched cellulolytic, thermophilic community. Phylogenomic analyses support the designation of OP9 as a candidate phylum for which we propose the name 'Atribacteria'.

Coordinating environmental genomics and geochemistry reveals metabolic transitions in a hot spring ecosystem.

We have constructed a conceptual model of biogeochemical cycles and metabolic and microbial community shifts within a hot spring ecosystem via coordinated analysis of the "Bison Pool" (BP) Environmental Genome and a complementary contextual geochemical dataset of ~75 geochemical parameters. 2,321 16S rRNA clones and 470 megabases of environmental sequence data were produced from biofilms at five sites along the outflow of BP, an alkaline hot spring in Sentinel Meadow (Lower Geyser Basin) of Yellowstone National Park. This channel acts as a >22 m gradient of decreasing temperature, increasing dissolved oxygen, and changing availability of biologically important chemical species, such as those containing nitrogen and sulfur.

Hydrothermal ecotones and streamer biofilm communities in the Lower Geyser Basin, Yellowstone National Park.

In Yellowstone National Park, a small percentage of thermal features support streamer biofilm communities (SBCs), but their growth criteria are poorly understood. This study investigates biofilms in two SBC hosting, and two non-SBC springs. Sequencing of 16S rRNA clones indicates changing community structure as a function of downstream geochemistry, with many novel representatives particularly among the Crenarchaeota.

Metabolic flexibility revealed in the genome of the cyst-forming alpha-1 proteobacterium Rhodospirillum centenum.

Background: Rhodospirillum centenum is a photosynthetic non-sulfur purple bacterium that favors growth in an anoxygenic, photosynthetic N2-fixing environment. It is emerging as a genetically amenable model organism for molecular genetic analysis of cyst formation, photosynthesis, phototaxis, and cellular development. Here, we present an analysis of the genome of this bacterium.

Characterization of photosystem I antenna proteins in the prasinophyte Ostreococcus tauri.

Prasinophyceae are a broad class of early-branching eukaryotic green algae. These picophytoplankton are found ubiquitously throughout the ocean and contribute considerably to global carbon-fixation. Ostreococcus tauri, as the first sequenced prasinophyte, is a model species for studying the functional evolution of light-harvesting systems in photosynthetic eukaryotes.

Phototroph genomics ten years on.

The onset of the genome era means different things to different people, but it is clear that this new age brings with it paradigm shifts that will forever affect biological research. Less clear is just how these shifts are changing the scope and scale of research. Are gigabases of raw data more useful than a single well-understood gene? Do we really need a full genome to understand the physiology of a single organism? The photosynthetic field is poised at the periphery of the bulk of genome sequencing work--understandably skewed toward health-related disciplines--and, as such, is subject to different motivations, limitations, and primary focus for each new genome.

The genome of Heliobacterium modesticaldum, a phototrophic representative of the Firmicutes containing the simplest photosynthetic apparatus.

Despite the fact that heliobacteria are the only phototrophic representatives of the bacterial phylum Firmicutes, genomic analyses of these organisms have yet to be reported. Here we describe the complete sequence and analysis of the genome of Heliobacterium modesticaldum, a thermophilic species belonging to this unique group of phototrophs. The genome is a single 3.

Integrating Markov clustering and molecular phylogenetics to reconstruct the cyanobacterial species tree from conserved protein families.

Attempts to classify living organisms by their physical characteristics are as old as biology itself. The advent of protein and DNA sequencing--most notably the use of 16S ribosomal RNA--defined a new level of classification that now forms our basic understanding of the history of life on earth. High-throughput sequencing currently provides DNA sequences at an unprecedented rate, not only providing a wealth of information but also posing considerable analytical challenges.

Niche adaptation and genome expansion in the chlorophyll d-producing cyanobacterium Acaryochloris marina.

Acaryochloris marina is a unique cyanobacterium that is able to produce chlorophyll d as its primary photosynthetic pigment and thus efficiently use far-red light for photosynthesis. Acaryochloris species have been isolated from marine environments in association with other oxygenic phototrophs, which may have driven the niche-filling introduction of chlorophyll d. To investigate these unique adaptations, we have sequenced the complete genome of A.

The complete genome sequence of Roseobacter denitrificans reveals a mixotrophic rather than photosynthetic metabolism.

Purple aerobic anoxygenic phototrophs (AAPs) are the only organisms known to capture light energy to enhance growth only in the presence of oxygen but do not produce oxygen. The highly adaptive AAPs compose more than 10% of the microbial community in some euphotic upper ocean waters and are potentially major contributors to the fixation of the greenhouse gas CO2. We present the complete genomic sequence and feature analysis of the AAP Roseobacter denitrificans, which reveal clues to its physiology.

Effect of iron on growth and ultrastructure of Acaryochloris marina.

The cyanobacterial genus Acaryochloris is the only known group of oxygenic phototrophs that contain chlorophyll d rather than chlorophyll a as the major photosynthetic pigment. Studies on this organism are still in their earliest stages, and biochemical analysis has rapidly outpaced growth optimization. We have investigated culture growth of the major strains of Acaryochloris marina (MBIC11017 and MBIC10697) by using several published and some newly developed growth media.