Emerging sampling and analytical methods based on high-throughput DNA sequencing, among others, are enabling microbial ecologists and microbiologists to rapidly and economically identify and characterize micro-organisms in the indoor environment. A project to bring microbiologists, bioinformaticians, microbial ecologists, and indoor and building scientists together to advance our understanding of the microbial ecology of the indoor environment is now under way. An opportunity exists to characterize simultaneously the microbial ecology and the indoor environmental factors associated with the presence and evolution of the species in any indoor environment. It is challenging to identify all of the relevant factors in advance of more extensive, collaborative research. This presentation presents what has been gleaned from the published literature, interviews with experts and a small, non-representative sample of scientists working in the relevant fields. The purpose of this review is to inform and stimulate discussions and collaboration among scientists working in the relevant fields.
Levin building ecology at Sloan Symposium, 2011
EHEC serotype O104 E. coli -- 93 percent sequence similarity with the EAEC 55989 E. coli strainBuilding Ecology: Linking Microbial Ecology with Indoor Environment and Building Science Hal Levin Building Ecology Research Group Santa Cruz, California email@example.com
Purpose of Presentation• Summarize preliminary findings and questions re: IE factors relevant to microbial ecology of the indoor environment• Stimulate discussion: what matters and why?• Ask better questions for future research• Stimulate potential collaboration between IE scientists and microbial ecologists• Identify subjects for microBEnet workshops, valuable pilot studies This is Bacillus subtilis, a ubiquitous bacterium whose spores are commonly found in house dust! On the left, the image of a colony grown on semi solid (agar) medium. On the right, a floating biofilm we call pellicle. Notice the complex architecture, wrinkles, ridges, aerial projections, etc.
Implications• A preliminary review of the scientific literature related to environmental factors that affect the indoor microbial ecology suggests the existence of an extremely complex system.• Future research will more comprehensively address indoor environmental microbial ecology with advanced gene- based tools.• This review identifies important factors determining the The pellicles are remarkably microbial species present in the robust… a penny thrown in does indoor environment. not break them…..
What is Building Ecology?• Buildings = more than inanimate physical entities, masses of inert material that remain relatively stable over time.• The building, what’s in it (occupants and contents), and what’s around it (the larger environment) – a interactive triad , all elements affect each other.• Buildings = dynamic combination of physical, chemical, and biological dimensions.• Buildings can (must?) be described and understood as complex systems.• Microbial ecology of the indoor environment illustrates the complexity.• Models, methods, and tools similar to those used by ecologists to understand ecosystems can help us understand the processes occurring out of sight, within the walls, and how those processes affect the durability and function of the building
The field of “microbial ecology” …• Seeks to understand how microbes interact with other organisms (including both macroorganisms and other microbes) and with the environment.• Like any other environment, buildings and other man-made objects provide rich habitats for microbes.• Buildings provide space and nutrients for microbes, and the people (and various animals and plants) passing through continually carry new species to the community.
What is Microbial Ecology?• Highly diverse activities from genetics to evolution to ecology• Ecologists looking at microbial communities in a wide range of locations, from deep ocean to tropical forests to• Microbiologists using new genomic methods• Metagenomics: (who’s there and what are they doing?) – Built environment: • Buildings houses (Moschandreas et al) • Urban environment – Diverse “natural” locations • Tropical forests • Oceans: surface, deep vents, etc.
What can microbial ecologists do in the indoor environment?• Identify the organisms or groups from which the organisms come• Identify the conditions that give rise to the organisms found• Identify the relationships or connections among the organisms or between organisms and environmental factors• Help us predict what microbes will be found based on IEQ factors
What can building scientists do to help the microbial ecologists?Carefully and thoroughly characterize the indoor environmental factors thought to be relevant to the microbes that are present.Identify mechanisms of interactions between environmental factors and microbial ecology
Purpose and Summary• Microbial ecologists characterizing indoor microbial ecology.• Sloan Foundation funding microbiologists, bioinformaticians, microbial ecologists, and indoor and building scientists to advance understanding of the indoor microbial ecology.• Simultaneous characterization of microbial ecology and associated indoor environmental factors will enable advances in both fields.• Challenging to identify all relevant factors before more extensive, collaborative research.• This presentation reviews preliminary efforts to identify the significant IE factors.• Purpose: inform and stimulate discussions and collaboration among scientists working in the relevant fields.
Microbial ecology is diverse• Genomes to human systems to ecosystems• Human microbiomes to global environmental systems• Characterizing abundance, diversity, evolution• Potential for prediction from indoor environmental characteristics• Is reverse prediction possible?: microbes to indoor environmental conditions
Focus of work to date• Attempt to find literature connecting environmental conditions, especially indoors, and the microbes found there• Sort through the diverse and abundant literature to identify prominent environmental factors as determinants of the microbial ecology of the indoor environment Biofilm of a fluorecently tagged Bacillus subtilis on the root of a tomato plant, keeping it growing well and keeping pathogens at bay.
Level 1 – strong connection hypothesized based on abundant evidence in the scientific literature:• Humidity: – Air: relative and absolute: for viruses, possibly as it contributes to vapor pressure – Surfaces: water activity as a function of air and material moisture content and temperatures.• Temperature: surface and air• Ventilation (outdoor air change rate and room air distribution or air flow patterns)• Surfaces of building materials (and furnishings) facing the enclosed space and in the structure• Chemicals and materials found primarily on surfaces but also in air (dust, organic matter, nutrients, biocides, others)• pH of moisture on surfaces: contribution of airborne chemicals (including CO2) to surface moisture Ph• People (age, size/activity/metabolic rate, culture)
Level 2–Important building components or processes w/ plausible connections, but either not strong or not well-established• Filtration• Cleaning practices• HVAC system – System type – Humidity in HVAC systems (Water blowing off coils, accumulated in drip pans, etc.) – Air conditioning (yes or no) – Humidifiers – UVc on wetted surfaces – Extent of drainage of water from HVAC surfaces• Envelope design and construction quality• Maintenance (building and HVAC) including frequency, materials and processes used• Type of materials used (e.g., plaster, vs. gypsum board, vs. the new mold- resistant gypsum board)• Flat vs pitched roofs – important as a function of prevalence of precipitation• Roof overhangs versus none• Operable windows vs. sealed and occupant window- opening behaviors.• Toilets as a source of microbial agents• Organic compounds comprising the dust in duct work (or on building surfaces)
Level 3 – Additional factors that may affect the microbial ecology of the indoor environment• Building location: – Biogeographical, e.g., latitudes, climates, historical factors (changes over time, past microbial populations and their evolution) – Climate factors: latitude: some fungi only appear to occur at certain latitudes, effects of severe storms, floods, weather cycles – Locality (as in adjacency to parks/natural areas/water bodies affecting what gets brought into a building - indoor/outdoor transport factors)• Building type (e.g. hospitals different from residences - this relates to human activities/building program)• Building design (overhangs, roofs, windows, etc. - and what about insulation? made a big difference in the condensation in my apartment!)• Building materials/furnishings: I came across the terms substrates and nutrients• Room types/activities (kitchens, bathrooms different from office, bedroom) - the word eco-niche was in one of the articles relating to bathrooms, I think• Light / darkness, Ultraviolet light• Potential effects of interactions of other air pollutants• Pets, house plants• Smoking behavior
Examples of dynamic, interactive and independent processes• Symbiosis between humans and gut flora• Temperature and humidity and emissions of chemicals from building materials, furnishings, and consumer productsI give you this as a reminder of the fact that in a very healthy pastoral state, afoundational aspect (keystone) is the colonization of all surfaces by microbes: the rootof the grass, the grass leaves, the fur on the sheep, their teeth, tongues and of course,the entrie surface of the intestinal tract. Same with us….
Endosymbiotic origin of eukaryotes Creg Darby: Micro 202, June 4, 2007
All microbes are not bad!Animal- microbe mutualisms Source: Creg Darby: Micro 202, June 4, 2007
Identify the “Patterns that Connect” Bateson, Mind and Nature: A Necessary Unity ENVIRONMENT MICROBES PEOPLE BUILDINGS
Think you very much!www.microBE.net SLOAN SYMPOSIUM – THURSDAY: 9:55 – 12:00, 1:00 – 3:00