@article{beasley_monsur_hu_dunn_madden_2022, title={The bacterial community of childcare centers: potential implications for microbial dispersal and child exposure}, volume={17}, ISSN={["2524-6372"]}, DOI={10.1186/s40793-022-00404-6}, abstractNote={Bacterial communities within built environments reflect differences in sources of bacteria, building design, and environmental contexts. These communities impact the health of their occupants in many ways. Children interact with the built environment differently than do adults as a result of their unique behaviors, size, and developmental status. Consequently, understanding the broader bacterial community to which children are exposed will help inform public health efforts and contribute to our growing understanding of the bacterial community associated with childcare centers.We sampled childcare centers to survey the variation in bacterial community composition across five surfaces found inside and outside twelve classrooms and six centers using 16S rRNA marker gene amplicon sequencing. We then correlated these bacterial community analyses of surfaces with environmental and demographic measures of illumination and classroom occupant density.The childcare environment was dominated by human-associated bacteria with modest input from outdoor sources. Though the bacterial communities of individual childcare centers differed, there was a greater difference in the bacterial community within a classroom than among centers. Surface habitats-fomites-within the classroom, did not differ in community composition despite differing proximity to likely sources of bacteria, and possible environmental filters, such as light. Bacterial communities did correlate with occupant density and differed significantly between high and low usage surfaces.Our results suggest built environments inhabited by young children are similar to functionally equivalent built environments inhabited by adults, despite the different way young children engage with their environment. Ultimately, these results will be useful when further interrogating microbial dispersal and human exposure to microorganisms in built environments that specifically cater to young children.}, number={1}, journal={ENVIRONMENTAL MICROBIOME}, author={Beasley, D. E. and Monsur, M. and Hu, J. and Dunn, R. R. and Madden, A. A.}, year={2022}, month={Mar} }
 @article{calvert_madden_nichols_haddad_lahne_dunn_mckenney_2021, title={A review of sourdough starters: ecology, practices, and sensory quality with applications for baking and recommendations for future research}, volume={5}, url={https://doi.org/10.7717/peerj.11389}, DOI={10.7717/peerj.11389}, abstractNote={The practice of sourdough bread-making is an ancient science that involves the development, maintenance, and use of a diverse and complex starter culture. The sourdough starter culture comes in many different forms and is used in bread-making at both artisanal and commercial scales, in countries all over the world. While there is ample scientific research related to sourdough, there is no standardized approach to using sourdough starters in science or the bread industry; and there are few recommendations on future directions for sourdough research. Our review highlights what is currently known about the microbial ecosystem of sourdough (including microbial succession within the starter culture), methods of maintaining sourdough (analogous to land management) on the path to bread production, and factors that influence the sensory qualities of the final baked product. We present new hypotheses for the successful management of sourdough starters and propose future directions for sourdough research and application to better support and engage the sourdough baking community.}, journal={PEERJ}, author={Calvert, Martha D. and Madden, Anne A. and Nichols, Lauren M. and Haddad, Nick M. and Lahne, Jacob and Dunn, Robert R. and McKenney, Erin A.}, year={2021}, month={May} }
 @article{madden_lahue_gordy_little_nichols_calvert_dunn_smukowski heil_2021, title={Sugar‐seeking insects as a source of diverse bread‐making yeasts with enhanced attributes}, volume={39}, ISSN={0749-503X 1097-0061}, url={http://dx.doi.org/10.1002/yea.3676}, DOI={10.1002/yea.3676}, abstractNote={Insects represent a particularly interesting habitat in which to search for novel yeasts of value to industry. Insect-associated yeasts have the potential to have traits relevant to modern food and beverage production due to insect-yeast interactions, with such traits including diverse carbohydrate metabolisms, high sugar tolerance, and general stress tolerance. Here, we consider the potential value of insect-associated yeasts in the specific context of baking. We isolated 63 yeast strains from 13 species of hymenoptera from the United States, representing 37 yeast species from 14 genera. Screening for the ability to ferment maltose, a sugar important for bread production, resulted in the identification of 13 strains of Candida, Lachancea, and Pichia species. We assessed their ability to leaven dough. All strains produced baked loaves comparable to a commercial baking strain of Saccharomyces cerevisiae. The same 13 strains were also grown under various sugar and salt conditions relevant to osmotic challenges experienced in the manufacturing processes and the production of sweet dough. We show that many of these yeast strains, most notably strains of Lachancea species, grow at a similar or higher rate and population size as commercial baker's yeast. We additionally assessed the comparative phenotypes and genetics of insect-associated S. cerevisiae strains unable to ferment maltose and identified baking-relevant traits, including variations in the HOG1 signaling pathway and diverse carbohydrate metabolisms. Our results suggest that non-conventional yeasts have high potential for baking and, more generally, showcase the success of bioprospecting in insects for identifying yeasts relevant for industrial uses.}, number={1-2}, journal={Yeast}, publisher={Wiley}, author={Madden, Anne A. and Lahue, Caitlin and Gordy, Claire L. and Little, Joy L. and Nichols, Lauren M. and Calvert, Martha D. and Dunn, Robert R. and Smukowski Heil, Caiti}, year={2021}, month={Nov}, pages={108–127} }
 @article{landis_oliverio_mckenney_nichols_kfoury_biango-daniels_shell_madden_shapiro_sakunala_et al._2021, title={The diversity and function of sourdough starter microbiomes}, volume={10}, ISSN={["2050-084X"]}, url={https://doi.org/10.7554/eLife.61644}, DOI={10.7554/eLife.61644}, abstractNote={Humans have relied on sourdough starter microbial communities to make leavened bread for thousands of years, but only a small fraction of global sourdough biodiversity has been characterized. Working with a community-scientist network of bread bakers, we determined the microbial diversity of 500 sourdough starters from four continents. In sharp contrast with widespread assumptions, we found little evidence for biogeographic patterns in starter communities. Strong co-occurrence patterns observed in situ and recreated in vitro demonstrate that microbial interactions shape sourdough community structure. Variation in dough rise rates and aromas were largely explained by acetic acid bacteria, a mostly overlooked group of sourdough microbes. Our study reveals the extent of microbial diversity in an ancient fermented food across diverse cultural and geographic backgrounds.Sourdough bread is an ancient fermented food that has sustained humans around the world for thousands of years. It is made from a sourdough ‘starter culture’ which is maintained, portioned, and shared among bread bakers around the world. The starter culture contains a community of microbes made up of yeasts and bacteria, which ferment the carbohydrates in flour and produce the carbon dioxide gas that makes the bread dough rise before baking. The different acids and enzymes produced by the microbial culture affect the bread’s flavor, texture and shelf life. However, for such a dependable staple, sourdough bread cultures and the mixture of microbes they contain have scarcely been characterized. Previous studies have looked at the composition of starter cultures from regions within Europe. But there has never been a comprehensive study of how the microbial diversity of sourdough starters varies across and between continents. To investigate this, Landis, Oliverio et al. used genetic sequencing to characterize the microbial communities of sourdough starters from the homes of 500 bread bakers in North America, Europe and Australasia. Bread makers often think their bread’s unique qualities are due to the local environment of where the sourdough starter was made. However, Landis, Oliverio et al. found that geographical location did not correlate with the diversity of the starter cultures studied. The data revealed that a group of microbes called acetic acid bacteria, which had been overlooked in past research, were relatively common in starter cultures. Moreover, starters with a greater abundance of this group of bacteria produced bread with a strong vinegar aroma and caused dough to rise at a slower rate. This research demonstrates which species of bacteria and yeast are most commonly found in sourdough starters, and suggests geographical location has little influence on the microbial diversity of these cultures. Instead, the diversity of microbes likely depends more on how the starter culture was made and how it is maintained over time.}, journal={ELIFE}, author={Landis, Elizabeth A. and Oliverio, Angela M. and McKenney, Erin A. and Nichols, Lauren M. and Kfoury, Nicole and Biango-Daniels, Megan and Shell, Leonora K. and Madden, Anne A. and Shapiro, Lori and Sakunala, Shravya and et al.}, year={2021}, month={Jan} }
 @misc{lahue_madden_dunn_smukowski heil_2020, title={History and Domestication of Saccharomyces cerevisiae in Bread Baking}, volume={11}, ISSN={["1664-8021"]}, DOI={10.3389/fgene.2020.584718}, abstractNote={The yeast Saccharomyces cerevisiae has been instrumental in the fermentation of foods and beverages for millennia. In addition to fermentations like wine, beer, cider, sake, and bread, S. cerevisiae has been isolated from environments ranging from soil and trees, to human clinical isolates. Each of these environments has unique selection pressures that S. cerevisiae must adapt to. Bread dough, for example, requires S. cerevisiae to efficiently utilize the complex sugar maltose; tolerate osmotic stress due to the semi-solid state of dough, high salt, and high sugar content of some doughs; withstand various processing conditions, including freezing and drying; and produce desirable aromas and flavors. In this review, we explore the history of bread that gave rise to modern commercial baking yeast, and the genetic and genomic changes that accompanied this. We illustrate the genetic and phenotypic variation that has been documented in baking strains and wild strains, and how this variation might be used for baking strain improvement. While we continue to improve our understanding of how baking strains have adapted to bread dough, we conclude by highlighting some of the remaining open questions in the field.}, journal={FRONTIERS IN GENETICS}, author={Lahue, Caitlin and Madden, Anne A. and Dunn, Robert R. and Smukowski Heil, Caiti}, year={2020}, month={Nov} }
 @article{reese_madden_joossens_lacaze_dunn_2020, title={Influences of Ingredients and Bakers on the Bacteria and Fungi in Sourdough Starters and Bread}, volume={5}, ISSN={["2379-5042"]}, DOI={10.1128/mSphere.00950-19}, abstractNote={Sourdough starters are complex communities of yeast and bacteria which confer characteristic flavor and texture to sourdough bread. The microbes present in starters can be sourced from ingredients or the baking environment and are typically consistent over time. Herein, we show that even when the recipe and ingredients for starter and bread are identical, different bakers around the globe produce highly diverse starters which then alter bread acidity and flavor. Much of the starter microbial community comes from bread flour, but the diversity is also associated with differences in the microbial community on the hands of bakers. These results indicate that bakers may be a source for yeast and bacteria in their breads and/or that bakers’ jobs are reflected in their skin microbiome.}, number={1}, journal={MSPHERE}, author={Reese, Aspen T. and Madden, Anne A. and Joossens, Marie and Lacaze, Guylaine and Dunn, Robert R.}, year={2020} }
 @article{lucas_madden_penick_epps_marting_stevens_fergus_dunn_meineke_2019, title={Azteca ants maintain unique microbiomes across functionally distinct nest chambers}, volume={286}, ISSN={["1471-2954"]}, DOI={10.1098/rspb.2019.1026}, abstractNote={The microbiome of built structures has considerable influence over an inhabitant's well-being, yet the vast majority of research has focused on human-built structures. Ants are well-known architects, capable of constructing elaborate dwellings, the microbiome of which is underexplored. Here, we explore the bacterial and fungal microbiomes in functionally distinct chambers within and outside the nests of Azteca alfari ants in Cecropia peltata trees. We predicted that A. alfari colonies (1) maintain distinct microbiomes within their nests compared to the surrounding environment, (2) maintain distinct microbiomes among nest chambers used for different functions, and (3) limit both ant and plant pathogens inside their nests. In support of these predictions, we found that internal and external nest sampling locations had distinct microbial communities, and A. alfari maintained lower bacterial richness in their ‘nurseries’. While putative animal pathogens were suppressed in chambers that ants actively inhabited, putative plant pathogens were not, which does not support our hypothesis that A. alfari defends its host trees against microbial antagonists. Our results show that ants influence microbial communities inside their nests similar to studies of human homes. Unlike humans, ants limit the bacteria in their nurseries and potentially prevent the build-up of insect-infecting pathogens. These results highlight the importance of documenting how indoor microbiomes differ among species, which might improve our understanding of how to promote indoor health in human dwellings.}, number={1908}, journal={PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES}, author={Lucas, Jane M. and Madden, Anne A. and Penick, Clint A. and Epps, Mary Jane and Marting, Peter R. and Stevens, Julia L. and Fergus, Daniel J. and Dunn, Robert R. and Meineke, Emily K.}, year={2019}, month={Jul} }
 @article{lyke_di fiore_fierer_madden_lambert_2019, title={Metagenomic analyses reveal previously unrecognized variation in the diets of sympatric Old World monkey species}, volume={14}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0218245}, abstractNote={Insectivory, or the consumption of insects and other arthropods, is a significant yet cryptic component of omnivorous primate diets. Here, we used high-throughput DNA sequencing to identify arthropods from fecal DNA and assess variation in insectivory by closely-related sympatric primates. We identified arthropod prey taxa and tested the hypothesis that variation in insectivory facilitates niche differentiation and coexistence among closely-related species with high dietary overlap. We collected 233 fecal samples from redtail (Cercopithecus ascanius; n = 118) and blue monkeys (C. mitis; n = 115) and used a CO1 metabarcoding approach to identify arthropod DNA in each fecal sample. Arthropod DNA was detected in 99% of samples (N = 223 samples), and a total of 68 families (15 orders) were identified. Redtails consumed arthropods from 54 families, of which 12 (21.8%) were absent from blue monkey samples. Blue monkeys consumed arthropods from 56 families, of which 14 (24.6%) were absent from redtail samples. For both species, >97% of taxa present belonged to four orders (Araneae, Diptera, Hymenoptera, Lepidoptera). Redtail samples contained more Lepidoptera taxa (p<0.05), while blue monkey samples contained more Araneae (p<0.05). Blue monkeys consumed a greater diversity of arthropod taxa than redtail monkeys (p<0.05); however, the average number of arthropod families present per fecal sample was greater in the redtail monkey samples (p<0.05). These results indicate that while overlap exists in the arthropod portion of their diets, 20-25% of taxa consumed are unique to each group. Our findings suggest that variation in arthropod intake may help decrease dietary niche overlap and hence facilitate coexistence of closely-related primate species.}, number={6}, journal={PLOS ONE}, author={Lyke, Martha M. and Di Fiore, Anthony and Fierer, Noah and Madden, Anne A. and Lambert, Joanna E.}, year={2019}, month={Jun} }
 @article{madden_epps_fukami_irwin_sheppard_sorger_dunn_2018, title={The ecology of insect–yeast relationships and its relevance to human industry}, volume={285}, ISSN={0962-8452 1471-2954}, url={http://dx.doi.org/10.1098/rspb.2017.2733}, DOI={10.1098/rspb.2017.2733}, abstractNote={Many species of yeast are integral to human society. They produce many of our foods, beverages and industrial chemicals, challenge us as pathogens, and provide models for the study of our own biology. However, few species are regularly studied and much of their ecology remains unclear, hindering the development of knowledge that is needed to improve the relationships between humans and yeasts. There is increasing evidence that insects are an essential component of ascomycetous yeast ecology. We propose a ‘dispersal–encounter hypothesis' whereby yeasts are dispersed by insects between ephemeral, spatially disparate sugar resources, and insects, in turn, obtain the benefits of an honest signal from yeasts for the sugar resources. We review the relationship between yeasts and insects through three main examples: social wasps, social bees and beetles, with some additional examples from fruit flies. Ultimately, we suggest that over the next decades, consideration of these ecological and evolutionary relationships between insects and yeasts will allow prediction of where new yeast diversity is most likely to be discovered, particularly yeasts with traits of interest to human industry.}, number={1875}, journal={Proceedings of the Royal Society B: Biological Sciences}, publisher={The Royal Society}, author={Madden, Anne A. and Epps, Mary Jane and Fukami, Tadashi and Irwin, Rebecca E. and Sheppard, John and Sorger, D. Magdalena and Dunn, Robert R.}, year={2018}, month={Mar}, pages={20172733} }
 @article{madden_boyden_soriano_corey_leff'_fierer_starks_2017, title={The emerging contribution of social wasps to grape rot disease ecology}, volume={5}, ISSN={["2167-8359"]}, DOI={10.7717/peerj.3223}, abstractNote={Grape sour (bunch) rot is a polymicrobial disease of vineyards that causes millions of dollars in lost revenue per year due to decreased quality of grapes and resultant wine. The disease is associated with damaged berries infected with a community of acetic acid bacteria, yeasts, and filamentous fungi that results in rotting berries with high amounts of undesirable volatile acidity. Many insect species cause the initial grape berry damage that can lead to this disease, but most studies have focused on the role of fruit flies in facilitating symptoms and vectoring the microorganisms of this disease complex. Like fruit flies, social wasps are abundant in vineyards where they feed on ripe berries and cause significant damage, while also dispersing yeasts involved in wine fermentation. Despite this, their possible role in disease facilitation and dispersal of grape rots has not been explored. We tested the hypothesis that the paper wasp Polistes dominulus could facilitate grape sour rot in the absence of other insect vectors. Using marker gene sequencing we characterized the bacterial and fungal community of wild-caught adults. We used a sterilized foraging arena to determine if these wasps transfer viable microorganisms when foraging. We then tested if wasps harboring their native microbial community, or those inoculated with sour rot, had an effect on grape sour rot incidence and severity using a laboratory foraging arena. We found that all wasps harbor some portion of the sour rot microbial community and that they have the ability to transfer viable microorganisms when foraging. Foraging by inoculated and uninoculated wasps led to an increase in berry rot disease symptom severity and incidence. Our results indicate that paper wasps can facilitate sour rot diseases in the absence of other vectors and that the mechanism of this facilitation may include both increasing host susceptibility and transmitting these microbial communities to the grapes. Social wasps are understudied but relevant players in the sour rot ecology of vineyards.}, journal={PEERJ}, author={Madden, Anne A. and Boyden, Sean D. and Soriano, Jonathan-Andrew N. and Corey, Tyler B. and Leff', Jonathan W. and Fierer, Noah and Starks, Philip T.}, year={2017}, month={Apr} }
 @article{madden_barberán_bertone_menninger_dunn_fierer_2016, title={The diversity of arthropods in homes across the United States as determined by environmental DNA analyses}, volume={25}, ISSN={0962-1083 1365-294X}, url={http://dx.doi.org/10.1111/mec.13900}, DOI={10.1111/mec.13900}, abstractNote={We spend most of our lives inside homes, surrounded by arthropods that impact our property as pests and our health as disease vectors and producers of sensitizing allergens. Despite their relevance to human health and well-being, we know relatively little about the arthropods that exist in our homes and the factors structuring their diversity. As previous work has been limited in scale by the costs and time associated with collecting arthropods and the subsequent morphological identification, we used a DNA-based method for investigating the arthropod diversity in homes via high-throughput marker gene sequencing of home dust. Settled dust samples were collected by citizen scientists from both inside and outside more than 700 homes across the United States, yielding the first continental-scale estimates of arthropod diversity associated with our residences. We were able to document food webs and previously unknown geographic distributions of diverse arthropods - from allergen producers to invasive species and nuisance pests. Home characteristics, including the presence of basements, home occupants and surrounding land use, were more useful than climate parameters in predicting arthropod diversity in homes. These noninvasive, scalable tools and resultant findings not only provide the first continental-scale maps of household arthropod diversity, but our analyses also provide valuable baseline information on arthropod allergen exposures and the distributions of invasive pests inside homes.}, number={24}, journal={Molecular Ecology}, publisher={Wiley}, author={Madden, Anne A. and Barberán, Albert and Bertone, Matthew A. and Menninger, Holly L. and Dunn, Robert R. and Fierer, Noah}, year={2016}, month={Nov}, pages={6214–6224} }