January 30, 2014
Architectural Design Dictates How Bacteria Thrive In Our Ecosystem
Brett Smith for redOrbit.com - Your Universe Online
If you're indoors right now – look around you. Everything you see has bacteria crawling all over it.Now that your germophobic senses have been stirred – you might be glad to learn that researchers from University of Oregon have conducted an analysis that could lead to healthier building designs that foster a favorable indoor bacterial community.
Published in the open access journal PLOS ONE, the study is based on the analysis of DNA from over 30,000 different types of bacteria throughout the Lillis Business Complex at UO. The researchers found that location, connectedness, and human use patterns in a building may affect the types of bacteria that it hosts.
"We found that what you do in a room, how many people there are in a room and how many different people are in a room all make a big difference," said James Meadow, a postdoctoral researcher in UO’s Biology and the Built Environment (BiBE) Center. "Even an office with one person year round versus a classroom with hundreds of people throughout the year will have different kinds of bacteria."
Individual buildings have their very own ecosystems of microorganisms. These microbes can play an integral role in human well-being and health.
To determine how design choices and human use have an impact on the bacteria in the building, scientists amassed microbiological, architectural, and environmental data from the complex's Lillis Hall – a massive 136,000-square-foot facility, which has air ventilation throughout most of the building, aside from a wing of offices where occupants chose window ventilation. The building was picked for the study because of its range of different uses and its flexible operation. For instance, Lillis Hall was intended to support both mechanical and passive air ventilation, allowing scientists to observe whether ventilation affects indoor bacterial communities.
The research team said they were not surprised by the types of bacteria they found, with proteobacteria, fermicutes and deinococci dominating the building.
"These are found about everywhere we look, inside or outside, and we found some of the same types of bacteria that you would expect to find living in soil and on plants,” Meadow said. “That tells us that some of the bacteria in buildings are likely being brought in with occupants and with outdoor air -- but not equally in all rooms."
Human gut bacteria, including lactobacillus, staphylococcus and clostridium, were most common in bathroom dust. The researchers found that bathrooms built up the most distinguishing bacterial communities, probably because of their unique function. The researchers said they did not screen for disease-causing pathogens.
Meadow called deinococcus the "oddballs" in the mix.
"They are super tough and can hang out in harsh conditions, and buildings present some harsh conditions. But they were some of the most common bacteria in the building,” he said. “They were found in all rooms, but more abundant in mechanically ventilated -- versus naturally ventilated -- rooms. That might suggest that they are accumulating over time while other bacteria dry out and die in buildings."
"This is a relatively new research area," he added. "We don't really have a list of bacteria that we know that we should come into contact with -- such as the Top 20 good bugs or the Top 20 bad bugs, except for maybe a few pathogens. At some point, we will, and this research helps us understand how architecture and occupant behavior can contribute to a healthier indoor microbiome."
Image Below: Video capture of an office worker and office covered in bacteria. Credit: TED/Jessica Green