Long-term dietary intake influences the structure and activity of the trillions of microorganisms residing in the human gut, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles.

/pdf/diet-rapidly-and-reproducibly-alters-the-human-gut-drvn0pi8vp.pdf

Diet rapidly and reproducibly alters the human gut microbiome

BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

“Bioinformatics” 특집을 내면서

Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes large introns, and can be insufficiently variable. Three subunits from the nuclear ribosomal RNA cistron were compared together with regions of three representative protein-coding genes (largest subunit of RNA polymerase II, second largest subunit of RNA polymerase II, and minichromosome maintenance protein). Although the protein-coding gene regions often had a higher percent of correct identification compared with ribosomal markers, low PCR amplification and sequencing success eliminated them as candidates for a universal fungal barcode. Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation. The nuclear ribosomal large subunit, a popular phylogenetic marker in certain groups, had superior species resolution in some taxonomic groups, such as the early diverging lineages and the ascomycete yeasts, but was otherwise slightly inferior to the ITS. The nuclear ribosomal small subunit has poor species-level resolution in fungi. ITS will be formally proposed for adoption as the primary fungal barcode marker to the Consortium for the Barcode of Life, with the possibility that supplementary barcodes may be developed for particular narrowly circumscribed taxonomic groups.

/pdf/nuclear-ribosomal-internal-transcribed-spacer-its-region-as-9rhgb6gvih.pdf

Nuclear ribosomal internal transcribed spacer (ITS) region as a universal DNA barcode marker for Fungi

The RefSeq project at the National Center for Biotechnology Information (NCBI) maintains and curates a publicly available database of annotated genomic, transcript, and protein sequence records (http://www.ncbi.nlm.nih.gov/refseq/). The RefSeq project leverages the data submitted to the International Nucleotide Sequence Database Collaboration (INSDC) against a combination of computation, manual curation, and collaboration to produce a standard set of stable, non-redundant reference sequences. The RefSeq project augments these reference sequences with current knowledge including publications, functional features and informative nomenclature. The database currently represents sequences from more than 55,000 organisms (>4800 viruses, >40,000 prokaryotes and >10,000 eukaryotes; RefSeq release 71), ranging from a single record to complete genomes. This paper summarizes the current status of the viral, prokaryotic, and eukaryotic branches of the RefSeq project, reports on improvements to data access and details efforts to further expand the taxonomic representation of the collection. We also highlight diverse functional curation initiatives that support multiple uses of RefSeq data including taxonomic validation, genome annotation, comparative genomics, and clinical testing. We summarize our approach to utilizing available RNA-Seq and other data types in our manual curation process for vertebrate, plant, and other species, and describe a new direction for prokaryotic genomes and protein name management.

Reference sequence (RefSeq) database at NCBI: current status, taxonomic expansion, and functional annotation

The nuclear ribosomal internal transcribed spacer (ITS) region is the formal fungal barcode and in most cases the marker of choice for the exploration of fungal diversity in environmental samples. Two problems are particularly acute in the pursuit of satisfactory taxonomic assignment of newly generated ITS sequences: (i) the lack of an inclusive, reliable public reference data set and (ii) the lack of means to refer to fungal species, for which no Latin name is available in a standardized stable way. Here, we report on progress in these regards through further development of the UNITE database (http://unite.ut.ee) for molecular identification of fungi. All fungal species represented by at least two ITS sequences in the international nucleotide sequence databases are now given a unique, stable name of the accession number type (e.g. Hymenoscyphus pseudoalbidus|GU586904|SH133781.05FU), and their taxonomic and ecological annotations were corrected as far as possible through a distributed, third-party annotation effort. We introduce the term ‘species hypothesis’ (SH) for the taxa discovered in clustering on different similarity thresholds (97–99%). An automatically or manually designated sequence is chosen to represent each such SH. These reference sequences are released (http://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and in the QIIME pipeline. The system and the data will be updated automatically as the number of public fungal ITS sequences grows. We invite everybody in the position to improve the annotation or metadata associated with their particular fungal lineages of expertise to do so through the new Web-based sequence management system in UNITE.

http://web.stanford.edu/~kpeay/papers/Koljalg_2013_MEC.pdf

Towards a unified paradigm for sequence-based identification of fungi

Azure dye-impregnated sheep's wool keratin (keratin azure) was incorporated in a high pH medium and overlaid on a keratin-free basal medium. The release and diffusion of the azure dye into the lower layer indicated production of keratinase. Fifty-eight fungal taxa, including 49 members of the Arthrodermataceae, Gymnoascaceae and Onygenaceae (Order Onygenales), were assessed for keratin degradation using this method. The results were comparable to measures of keratin utilization reported in studies using tests based on the perforation or erosion of human hair in vitro.

/pdf/determination-of-keratin-degradation-by-fungi-using-keratin-1b1vhtvx3o.pdf

Determination of keratin degradation by fungi using keratin azure.

We examined 198 isolates of P. chysogenum recovered from 109 houses in Wallaceburg, Ontario, and 25 culture collection isolates including seven ex- type strains. Multilocus genotypes were determined by heteroduplex mobility assay of regions spanning introns in acetyl co-enzyme A synthase, beta-tubulin, thioredoxin reductase and the internal transcribed spacer regions of the nuclear ribosomal subrepeat. Five unique multilocus haplotypes were revealed without evidence of recombination, indicating strictly clonal population structures. Phylogenetic analysis of allele sequences using maximum parsimony resolved three strongly supported lineages. The dominant clade included more than 90% of house isolates in addition to the notable laboratory contaminant iso- lated by Alexander Fleming in 1929 in Britain. A sec- ond clade contained more than 5% of house isolates clustered with the ex-type strains of P. chysogenum and P. notatum. Follow-up sampling of outdoor air in the locality failed to reveal P. chysogenum, confirming the rarity of this fungus in outdoor air.

/pdf/genotypic-variation-in-penicillium-chysogenum-from-indoor-pgrj2fwmor.pdf

Genotypic variation in Penicillium chysogenum from indoor environments

The lichenicolous anamorphic fungus Sclerococcum parmeliae was isolated in pure culture, and ITS, nuLSU and mtSSU sequences were obtained from these isolates. For comparison, sequences from S. sphaerale, the generic type, were obtained directly from freshly collected specimens. Phylogenetic analyses place S. sphaerale with species of Dactylospora and an unidentified lichen-inhabiting isolate in a strongly supported clade that is sister to a lineage comprising members of the Chaetothyriales and Pyrenulales. In contrast, S. parmeliae is inferred as a member of the Herpotrichiellaceae (Chaetothyriales) and belongs to a robustly supported clade that also includes species of Cladophialophora, Capronia semiimmersa, and Phialophora verrucosa. Within the Herpotrichiellaceae, S. parmeliae most closely resembles members of the anamorph genus Cladophialophora. Accordingly, we propose the transfer of S. parmeliae and the morphologically similar species S. cladoniae, S. hawksworthii and S. normandinae to Cladophialophora. A new lichenicolous species, Clad. megalosporae, collected twice on Megalospora in Florida and Papua New Guinea, is also described.

Molecular data place the hyphomycetous lichenicolous genus Sclerococcum close to Dactylospora (Eurotiomycetes) and S. parmeliae in Cladophialophora (Chaetothyriales)

Baudoinia gen. nov. is described to accommodate Torula compniacensis. Reported originally from the walls of buildings near brandy maturation warehouses in Cognac, France, species of Baudoinia are cosmopolitan colonists of exposed surfaces subjected to large diurnal temperature shifts, episodic high relative humidity and wetting, and ambient airborne ethanol. Morphologically B. compniacensis resembles some anamorphic Mycosphaerellaceae in possessing dark brown, nonseptate or uniseptate conidia with coarsely roughened walls that are borne acropetally in unbranched chains and released by schizolytic dehiscence. Analysis of partial nuclear rDNA SSU sequences positions B. compniacensis in the order Capnodiales and reveals that it is most closely related to the microcolonial genus Friedmanniomyces. Heat resistance is induced by brief sublethal temperature exposure.

Baudoinia, a new genus to accommodate Torula compniacensis

The genus Capronia includes a number of lichenicolous (lichen-inhabiting) species, none of which have previously been characterized in vitro or considered in molecular phylogenetic studies. We cultured Capronia peltigerae from Peltigera rufescens and report here the growth of this species on a variety of media and its phylogenetic position based on the analyses of nuclear ribosomal RNA, mitochondrial ribosomal RNA, and RNA polymerase II (RPB1) gene sequences. This species differs from the majority of Capronia studied in axenic culture in lacking a conidial anamorph. Phylogenetic analyses position C. peltigerae outside the Herpotrichiellaceae within a robustly supported basal lineage of the Chaetothyriales composed primarily of melanized, rock-inhabiting anamorphic fungi. Our results demonstrate that Capronia, as circumscribed currently, is polyphyletic, but they do not resolve the relationship of C. peltigerae with members of the Chaetothyriaceae.

/pdf/the-phylogenetic-position-of-the-lichenicolous-ascomycete-1rj6rn01no.pdf

Wendy A. Untereiner

Papers

Determination of keratin degradation by fungi using keratin azure.

Genotypic variation in Penicillium chysogenum from indoor environments

Molecular data place the hyphomycetous lichenicolous genus Sclerococcum close to Dactylospora (Eurotiomycetes) and S. parmeliae in Cladophialophora (Chaetothyriales)

Baudoinia, a new genus to accommodate Torula compniacensis

The phylogenetic position of the lichenicolous ascomycete Capronia peltigerae