The Amazon Rainforest is a global diversity hotspot that has experienced a significant level of deforestation over the past half century, primarily for the establishment of cattle pasture. Characterizing the impact of this large-scale ecosystem conversion on the composition and activity of the soil microbial community is crucial for understanding potentially consequential shifts in nutrient… [Read More]
Mechanistic insights into consumption of the food additive xanthan gum by the human gut microbiota
Processed foods often include food additives such as xanthan gum, a complex polysaccharide with unique rheological properties, that has established widespread use as a stabilizer and thickening agent. Xanthan gum’s chemical structure is distinct from those of host and dietary polysaccharides that are more commonly expected to transit the gastrointestinal tract, and little is known… [Read More]
Considering Strain Variation and Non-Type Strains for Yeast Metabolic Engineering Applications
A variety of yeast species have been considered ideal hosts for metabolic engineering to produce value-added chemicals, including the model organism Saccharomyces cerevisiae, as well as non-conventional yeasts including Yarrowia lipolytica, Kluyveromyces marxianus, and Pichia pastoris. However, the metabolic capacity of these microbes is not simply dictated or implied by genus or species alone. Within… [Read More]
Critical Assessment of Metagenome Interpretation: the second round of challenges
Evaluating metagenomic software is key for optimizing metagenome interpretation and focus of the Initiative for the Critical Assessment of Metagenome Interpretation (CAMI). The CAMI II challenge engaged the community to assess methods on realistic and complex datasets with long- and short-read sequences, created computationally from around 1,700 new and known genomes, as well as 600… [Read More]
A generalist–specialist trade-off between switchgrass cytotypes impacts climate adaptation and geographic range
Polyploidy results from whole-genome duplication and is a unique form of heritable variation with pronounced evolutionary implications. Different ploidy levels, or cytotypes, can exist within a single species, and such systems provide an opportunity to assess how ploidy variation alters phenotypic novelty, adaptability, and fitness, which can, in turn, drive the development of unique ecological… [Read More]
Chromosome evolution and the genetic basis of agronomically important traits in greater yam
The nutrient-rich tubers of the greater yam, Dioscorea alata L., provide food and income security for millions of people around the world. Despite its global importance, however, greater yam remains an orphan crop. Here, we address this resource gap by presenting a highly contiguous chromosome-scale genome assembly of D. alata combined with a dense genetic… [Read More]
The Genome of the Acid Soil-Adapted Strain Rhizobium favelukesii OR191 Encodes Determinants for Effective Symbiotic Interaction With Both an Inverted Repeat Lacking Clade and a Phaseoloid Legume Host
Although Medicago sativa forms highly effective symbioses with the comparatively acid-sensitive genus Ensifer, its introduction into acid soils appears to have selected for symbiotic interactions with acid-tolerant R. favelukesii strains. Rhizobium favelukesii has the unusual ability of being able to nodulate and fix nitrogen, albeit sub-optimally, not only with M. sativa but also with the… [Read More]
Genome Streamlining, Proteorhodopsin, and Organic Nitrogen Metabolism in Freshwater Nitrifiers
Microbial nitrification is a critical process governing nitrogen availability in aquatic systems. Freshwater nitrifiers have received little attention, leaving many unanswered questions about their taxonomic distribution, functional potential, and ecological interactions. Here, we reconstructed genomes to infer the metabolism and ecology of free-living picoplanktonic nitrifiers across the Laurentian Great Lakes, a connected series of five… [Read More]
Ecological and genomic responses of soil microbiomes to high-severity wildfire: linking community assembly to functional potential
Increasing wildfire severity, which is common throughout the western United States, can have deleterious effects on plant regeneration and large impacts on carbon (C) and nitrogen (N) cycling rates. Soil microbes are pivotal in facilitating these elemental cycles, so understanding the impact of increasing fire severity on soil microbial communities is critical. Here, we assess… [Read More]
Near-Complete Genome Sequence of Zygosaccharomyces rouxii NRRL Y-64007, a Yeast Capable of Growing on Lignocellulosic Hydrolysates
The halotolerant and osmotolerant yeast Zygosaccharomyces rouxii can produce multiple volatile compounds and has the ability to grow on lignocellulosic hydrolysates. We report the annotated genome sequence of Z. rouxii NRRL Y-64007 to support its development as a platform organism for biofuel and bioproduct production. [Read More]