Changes in Microbes of the Built Environment in Early Stages of Urbanization


In our previous 2012 Sloan project “Microbes of the built environment spanning human urbanization” we studied environmental microbes in gradients of transculturation and of urban social stratification at the basin of the Amazon River, from hunter-gatherer villages in Peru, to the modern city of Manaus. The results showed an association between changes in home designs (based on urbanization, i.e. enclosing the houses) and increased presence of human microbes, at the expense of environmental microbes. Also, we found that bacterial profiles of walls, reflect use of space. These results are currently in revision for publication. This study spanned urbanization extremes, with many factors associated to transculturation changing concomitantly.

Since the changes in home microbes were so remarkable in such a broad urbanization scope, our new study focuses on a narrower urbanization gradient, with fewer confounding transculturation factors. The study will add knowledge to results from the Sloan project “Microbes across cultures”.



Fig 1. A Yekwana community, with architectural creole influence


Thus, we are comparing environmental parameters and home microbes in isolated traditional Amerindian villages which are inaccessible by land, with architectural/urban features with (Fig 1) or without (Fig 2) mestizo influence. Using the protocols of the previous Sloan project in Peru and Brazil, we are sampling home walls and floors, drawing urban plans of communities and architectural plans of houses, and measuring environmental parameters in the homes, in collaboration with Architects Edwin de la Cruz and Humberto Cavallin from University of Puerto Rico, MD Oscar Noya from Universidad Central de Venezuela, Microbiologist Monica Contreras from IVIC in Venezuela, and Environmental Engineer Atila Novoselak from University of Texas.



Fig 2. A Sanema (left) and Yekwana (right) communities, without architectural mestizo influence


We plan to study the structure of bacterial (16S) and fungal (ITS) profiles and perform metabolite analyses on selected samples, in collaboration with Rob Knight, and Peter Dorrestein, from University of California San Diego. The present study will add information on the impact of urban and architectural changes in traditional villages, and will allow comparison with home samples already available from hunter gatherer settings in Peru and Tanzania, constituting a unique effort to understand the built environment at very early stages of transculturation.



Fig 3. Architect Edwin de la Cruz, drawing architectural and urban plans in first field trip

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