Microbiome digest, August 17, 2014

Childhood undernutrition and the gut microbiome, hibernating ground squirrels, Sphagnum, nematodes, and forensic discrimination of soils.

Human gut microbiome

An evolving perspective about the origins of childhood undernutrition and nutritional interventions that includes the gut microbiome – Tahmeed Ahmed – Annals of the New York Academy of Sciences

“This paper summarizes work on mechanisms underlying the varied manifestations of childhood undernutrition and discusses current gaps in knowledge and challenges to our understanding of undernutrition and infection/immunity throughout the human life cycle, focusing on early childhood growth. ”

Animal microbiome

Hibernation alters the diversity and composition of mucosa-associated bacteria while enhancing antimicrobial defense in the gut of 13-lined ground squirrels – Kimberly A. Dill-McFarland – Molecular Ecology

“We used 16S rRNA pyrosequencing and cecal tissue protein analysis to investigate the effects of hibernation on the mucosa-associated bacterial microbiota and host responses in 13-lined ground squirrels.”

Diversity of Bacteria Carried by Pinewood Nematode in USA and Phylogenetic Comparison with Isolates from Other Countries – Diogo Neves Proença – PLOS ONE

“The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. “

Plant microbiome

The Sphagnum microbiome supports bog ecosystem functioning under extreme conditions – Anastasia Bragina – Molecular Ecology

“We identified a high functional diversity within the Sphagnum microbiome applying an Illumina-based metagenomic approach followed by de novo assembly and MG-RAST annotation.”

Soil microbiome

Random Whole Metagenomic Sequencing for Forensic Discrimination of Soils – Anastasia S. Khodakova – PLOS ONE

“Shotgun, whole genome amplification (WGA) and single arbitrarily primed DNA amplification (AP-PCR) based sequencing techniques were then used to generate soil metagenomic profiles”

Microbial Community Structure of Relict Niter-Beds Previously Used for Saltpeter Production – Takashi Narihiro – PLOS ONE

“In this study, the microbial community structures within nine relict niter-bed soils were investigated using 454 pyrotag analysis targeting the 16S rRNA gene and the bacterial and archaeal ammonia monooxygenase gene (amoA). “

How Does Conversion of Natural Tropical Rainforest Ecosystems Affect Soil Bacterial and Fungal Communities in the Nile River Watershed of Uganda? – Peter O Alele – PLOS ONE

“Overall, our results suggest that soil microbial communities are relatively resilient to forest conversion and despite a substantial and consistent change in the soil environment, the effects of conversion differed widely among sites. “

Soil-Borne Microbial Functional Structure across Different Land Uses – Eiko E. Kuramae – The Scientific World Journal

“In a multivariate regression tree analysis of soil physicochemical properties and genes detected by functional microarrays, the main factor that explained the different microbial community functional structures was C : N ratio.”

Water microbiome

Temperature response of denitrification and anammox rates and microbial community structure in Arctic fjord sediments – Andy Canion – Environmental Microbiology

“Community structure in intact sediments and slurry incubations was determined using Illumina MiSeq SSU rRNA gene sequencing.”

Complex communities of small protists and unexpected occurrence of typical marine lineages in shallow freshwater systems – Marianne Simon – Environmental Microbiology

“We carried out a comparative study based on massive pyrosequencing of amplified 18S rRNA gene fragments of protists in the 0.2-5 μm-size range in one brook and four shallow ponds located in the Natural Regional Park of the Chevreuse Valley, France.”

Metagenomics

Impact of single-cell genomics and metagenomics on the emerging view of extremophile “microbial dark matter” – Brian P. Hedlund- Extremophiles

“Unraveling the mysteries of these candidate phyla is a grand challenge in microbiology and is especially important in habitats where they are abundant, including some extreme environments and low-energy ecosystems.”

Metabolomics

Metabolic Modelling of Spatial Heterogeneity of Biofilms in Microbial Fuel Cells Reveals Substrate Limitations in Electrical Current Generation – Nadeera Jayasinghe – Biotechnology Journal

“The goal of this work is to develop a model that integrates genome-scale metabolic models with the model of biofilm environment. “

Bioinformatics

Rarefaction and extrapolation of phylogenetic diversity – Anne Chao – Methods in Ecology and Evolution

“We develop in this paper the “PD accumulation curve” (an extension of the species accumulation curve) to depict how PD increases with sampling size and sample completeness.”

Microbes in the news

Can’t Stick to That Diet? Blame Your Gut Bacteria – Nolan Feeney – Time

“The gut microbiome, the collection of all the microbes in our digestive tracts, may influence our food choices and behavior, suggests a new study that recently appeared in the journal BioEssays.”

How Clean Is Your Produce? Testing Fruit For Bacteria – WFMyNews2.com

“Ellis took samples of the fruits one by one and placed the samples on a petri dish. She then washed some of the lettuce and repeated the testing procedure on both the head of lettuce and the pre-washed bag of lettuce, in 72-hours the results were in.”

Bik’s Picks

9/11 dust cloud may have caused widespread pregnancy issues – ScienceDaily

“Pregnant women living near the World Trade Center during the 9/11 attacks experienced negative birth outcomes, according to a new paper.”

Volunteers on the scent of science with whale carcass – Peter Fimrite – SF Gate

“If there’s anything as enjoyable to Dan Sudran as sawing through the stinking blubber of a whale carcass and extracting bones from the gooey tissues, it would be showing the results to children.”

Alaska’s Shrinking Glaciers Seen from Space – Kelly Dickerson – LiveScience

“Compared with a vintage satellite photo of the region, an image taken from space last year reveals just how much the glaciers have shrunk over the past 26 years.”

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Non-human microbiome, June 23

What happens with all that triclosan we flush down the drain? Also, baby squirrels, tse-tse flies, pot, and Chinese liquor.

Animal microbiome general 

Two very different papers from the same group, but both are finding that Blautia species are host specific.

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A single genus in the gut microbiome reflects host preference and specificity – A Murat Eren – The ISME Journal

“In our dataset of 57 M sequence reads of the V6 region of the 16S ribosomal RNA gene in samples collected from seven host species, we identified 200 high-resolution taxonomic units within Blautia using oligotyping.” (Humans, cows, swine, deer, chickens)

Screen Shot 2014-06-23 at 11.26.18 PMBlautia and Prevotella sequences distinguish human and animal fecal pollution in Brazil surface waters – Amber M. Koskey – Environmental Microbiology Reports

“We used oligotyping to identify Prevotella and Blautia sequences that can distinguish human fecal contamination. Thirty-five of 61 Blautia oligotypes and 13 of 108 Prevotella oligotypes in humans were specific to or highly abundant (i.e. host-preferred) compared to pig, dog, horse, and cow sources.”

Squirrel microbiome

Screen Shot 2014-06-23 at 11.35.26 PMTemporal Dynamics of the Cecal Gut Microbiota of Juvenile Arctic Ground Squirrels: a Strong Litter Effect across the First Active Season – Timothy J. Stevenson – Applied and Environmental Microbiology  (image courtesy of ego-alterego.com)

“We characterized trends in diversity (454 pyrosequencing), density (flow cytometry), viability (flow cytometry), and metabolism (short-chain fatty acid analysis) of the gut microbial community of juvenile arctic ground squirrels across their first active season at weaning and at 4, 6, 8, and 10 weeks postweaning.”

Insect microbiome

Screen Shot 2014-06-23 at 11.20.33 PMAnalysis of Multiple Tsetse Fly Populations in Uganda Reveals Limited Diversity and Species-Specific Gut Microbiota – Emre Aksoy – Applied and Environmental Microbiology

“We used multiple approaches, including deep sequencing of the V4 hypervariable region of the 16S rRNA gene, 16S rRNA gene clone libraries, and bacterium-specific quantitative PCR (qPCR), to investigate the levels and patterns of gut microbial diversity from a total of 151 individuals.”

Screen Shot 2014-06-23 at 11.22.49 PMMicrobial Population Dynamics in the Hemolymph of Manduca sexta Infected with Xenorhabdus nematophila and the Entomopathogenic Nematode Steinernema carpocapsae – Swati Singh – Applied and Environmental Microbiology

“We show that gut microbes translocate into the hemolymph when the nematode penetrates the insect intestine.”

Screen Shot 2014-06-23 at 11.23.22 PMPurine Biosynthesis, Biofilm Formation, and Persistence of an Insect-Microbe Gut Symbiosis – Jiyeun Kate Kim – Applied and Environmental Microbiology

“When we disrupted purN and purT in the Burkholderia symbiont, the ΔpurN and ΔpurT mutants grew normally, and only the ΔpurT mutant failed to form biofilms. “

Plant microbiome

Plant metabolomics for plant chemical responses to belowground community change by climate change – Sangkyu Park – Journal of Plant Biology

“In this review, we will first summarize recent progress in plant metabolomics methodology and subsequently review recent studies of interactions between plants and soil organisms in relation to climate change issues.”

Bioreactor and sewage microbiology

TriclosanThe Impacts of Triclosan on Anaerobic Community Structures, Function, and Antimicrobial Resistance – Patrick J McNamara – Environmental Science & Technology

“Triclosan amendment caused all of the Bacteria and Archaea communities to structurally diverge from that of the control cultures (based on ARISA).”

Screen Shot 2014-06-23 at 11.24.07 PMShifts in the Microbial Community, Nitrifiers and Denitrifiers in the Biofilm in a Full-scale Rotating Biological Contactor – Xingxing Peng – Environmental Science & Technology

“The objective of this study was to investigate the Microbial community shifts of bacteria, especially nitrifiers and denitrifiers, in the biofilm of two rotating biological contactor (RBC) trains with different running times along the plug flowpath”

Soil microbiology

Screen Shot 2014-06-23 at 11.32.29 PMIdentifying qualitative effects of different grazing types on below-ground communities and function in a long-term field experiment – Catriona A Macdonald – Environmental Microbiology

“All functional community measures (functions, biogeochemical cycling genes, network association between different taxa) were more strongly affected by invertebrate grazers than rabbits.”

Screen Shot 2014-06-23 at 11.25.34 PMExtensive sampling of basidiomycete genomes demonstrates inadequacy of the white-rot/brown-rot paradigm for wood decay fungi – Robert Riley – PNAS

“To test the adequacy of the white/brown-rot categories, we analyzed 33 fungal genomes. Some species lack PODs, and thus resemble brown-rot fungi, but possess the cellulose-degrading apparatus typical of white-rot fungi. “

Food and other consumables microbiology

Screen Shot 2014-06-23 at 11.33.28 PMIf the pot doesn’t worry you, the bacteria might: Food safety a new frontier for legal pot – Kristen Wyatt – The Republic

“In Washington state, where retail sales are expected to begin the week of July 7, regulations call for samples of all marijuana sold for consumption to clear a “microbiological screening,” whether it’s in edible, smokeable or concentrate form.”

Screen Shot 2014-06-23 at 11.34.50 PMStarter Culture Selection for Making Chinese Sesame-Flavored Liquor Based on Microbial Metabolic Activity in Mixed-Culture Fermentation – Qun Wu – Applied and Environmental Microbiology

“To obtain a suitable starter culture for making Chinese sesame-flavored liquor, the yeast and bacterium community structures were investigated during spontaneous and solid-state fermentations of this type of liquor.”

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