This grant supports a team led Noah Fierer, associate professor at the University of Colorado; Rob Dunn, associate professor at North Carolina State; and Shelly Miller, an environmental engineer and associate professor at the University of Colorado to characterize the diversity of microbial communities in homes throughout the United States. Tapping a network of more than 6,500 volunteers across the U.S., Fierer and his team will collect information on volunteer homes and distribute "home sampling kits" which direct volunteers to collect swabs of the microbial populations living in four locations in the home: the outer door frame above the entrance to the residence, a door frame above an interior door, a kitchen countertop where food is prepared, and a pillowcase on a bed. As a complement to the larger study, the team will conduct a detailed study of the microbial populations in 50 homes in the Boulder, Colorado region, collecting microbial samples on multiple occasions and making a variety of building measurement, including humidity, temperature, and levels of carbon monoxide and carbon dioxide. Taken together, the two studies will permit the construction of what promises to be the most complete picture of how residential microbial communities differ across the United States and will provide a huge dataset that can be used to generate and test hypotheses on what factors drive the compositional diversity of microbial communities in the built environment.

To date over 750,000 homes have been weatherized in the U.S. Department of Energy's Weatherization Assistance program to help homeowners make their homes more energy efficient. Some of the energy efficient upgrades-such as sealing ducts and installing more efficient windows-reduce the levels of ventilation in homes, resulting in changes that could influence the size, composition, location, or diversity of microbial communities inside the home. Funds from this grant support a two-year pilot study by Largus Angenent, associate professor in of biological and environmental engineering at Cornell University to investigate and characterize how weatherization changes in indoor airborne microbiota of homes. Angenent will study fifteen homes in the Finger Lakes region of New York State, sampling the air both inside and outside a home immediately before it is weatherized, directly after weatherization is completed, and again six months later. Analysis of the collected samples will provide preliminary data that suggest how weatherization changes microbial communities and, depending on results, could form the basis for further data collection and research by the U.S. Department of Energy or some other federal agency.

This grant to architect Rob Van Pelt and biologist Rob Knight will support a one-year project to create a "proof of concept" detailed 3D map of the "Microbially Visible Home." This map will include both the architectural components and microbial data of a single house and will bring together building scientists, software developers, and microbiologists to create an easily interpretable and visual 3D model. Partnering with Autodesk, a world leader in 3D design software for manufacturing, buildings, construction, engineering, and entertainment, Van Pelt, Knight and their team will conduct dense sampling of homes near Toronto, collecting and analyzing nearly 1,000 samples for bacteria and fungi and using this data to build a biological data layer on top of Autodesk's Building Information Model, a computable representation of a facility that integrates a wide range of building features and functions, including architectural characteristics, materials, relationships, sensor data, and performance metrics. The result will be the creation of a detailed 3D building map with both the architectural components and the microbial data. It will make the invisible microbial world of one home visible. This new tool will help scientists develop exploratory hypotheses about why microbes live in the locations that they do.

We know there are microbes in homes. We know there are microbes in and on people. Are the microbes of homes and their inhabitants the same? Funds from this grant support a two-year project by microbiologist Maria Gloria Domнnguez-Bello, architect Humberto Cavallin, and colleagues at the University of Puerto Rico to collect and analyze microbial samples from homes and their inhabitants in a variety of cultural settings. The team plans to collect samples from traditional dwellings in remote villages in the Amazon as well as more modern rural and urban homes in New York City and South America. The homes in the Amazon villages are round huts constructed of natural materials without windows, closets, or furniture. The inhabitants of these homes have had very little exposure to modern life. The rural homes are far more advanced. They have two or three bedrooms and electricity, but do not necessarily have running water. Each room has a door and window with modest furniture and natural or forced ventilation using fans but no air conditioning. The urban homes are the most advanced and generally have air conditioning. In each home, the team will collect and analyze samples from the home as well as from the human and animal inhabitants. This project promises to generate important new knowledge about the microbiology of homes across cultures as well as shed some light on the relationship between the microbiomes of the home and its inhabitants.

Little is known about the biology of microbial populations living in our drinking water. Current systems monitor drinking water for the absence of fecal bacteria using coliform counts, a very old method, and for total bacterial load, which is determined by growing cultures of bacteria found in water samples. Yet 99.99% of bacteria cannot be successfully grown in culture, and thus are missed by using such methods. Our drinking water, in other words, is monitored using very old and inaccurate techniques. This three year grant will fund a project led by Professor Norman Pace at the University of Colorado, Boulder, to use state-of-the art gene sequencing techniques to begin to characterize the microbial populations in municipal water delivery systems. Preliminary work by Pace and his research team on the municipal water supply in Boulder, Colorado has revealed a diverse and (perhaps) stable microbial profile in the Boulder municipal water system, one that differs significantly from the microbial populations in water supplies in New York, New Orleans, and Austin. Funds from this grant will allow Pace to continue and expand this work, as well as provide support for a smaller project to measure how concrete degradation, a common problem in aging municipal water deliver infrastructure, affects microbial populations in the water supply, and funds to complete Pace's ongoing work examining how the flooding of an engineering building on the University of Colorado, Boulder campus changed the characteristics of microbial communities inside the building.

The goal of the Foundation's Indoor Environment program is to grow a new field of scientific inquiry that eventually will be funded by traditional U.S. government funding agencies. This grant to Mark Hernandez of the University of California, Boulder will fund three annual conferences to bring together the large, diverse, multidisciplinary community of biologists, engineers, architects, and others studying the microbiology of built environments. At the conferences, scientists will share research results, develop and advance a coordinated research agenda for studying indoor microbial populations, and educate NGOs and key federal agencies about the importance of directing research and regulatory to this new field of inquiry.

Babies are born sterile. The microbial ecosystem that thrives on and inside each of us-stomach bacteria that help us digest food, for instance-are acquired post-birth, presumably through contact with our mothers. But what of babies born prematurely, separated from their mothers, and treated in sterile neonatal intensive care units? How do these infants acquire the microbes needed to survive outside the womb? This grant supports the research of UC, Berkeley professor Jill Banfield, who is investigating this very question. In a one-year pilot study with collaborator Dr. Michael Morowitz of the University of Pittsburgh Medical Center, Banfield will examine the microbial profiles of the air, water, and surfaces of a neonatal intensive care unit and compare the profiles to those found in the gut of three premature infants staying in the ICU. Using modern molecular tools, the research team will analyze the microbial profiles of the neonatal intensive care unit environments over time and space to potentially identify the sources of microbes involved in infant gut colonization.

This two-year grant to Yale University provides support to Professors Bill Nazaroff and Jordan Peccia to continue their ongoing work characterizing airborne microbial populations of indoor environments. The team will study the size distributions of bioaerosols from the indoor environment under occupied and unoccupied conditions. They will examine the sources, origins, and population characteristics of airborne bacteria and fungi in indoor settings that are attributable to human occupancy and collect and analyze air and dust samples from 10 different indoor environments-all elementary schools in the U.S., Germany, and China. Collected samples will help shed light on how airborne bacteria and fungi differ from other airborne particulate matter, how internal physical processes in indoor environments shape bacterial and fungal size distributions, and the role human occupants play in shaping microbial populations in indoor air.