EAGER: Rapid isolation of live microbial species from environmental communities

Arizona State University, Scottsdale AZ

Investigators

Abstract

Microbes are everywhere, and they play major roles in ecosystem function and human health. However, studying microbes is challenging because they are so small and because they live in complex communities. Most microbial species cannot be cultivated in the lab. Therefore, to understand the diversity, evolution, and ecology of microbes, scientists typically extract bulk DNA from the environment. This can reveal which types of microbes are present, but it does not provide information about what each species looks like and which species are carrying out which processes. In this project, researchers will develop a device to separate complex microbial communities into their individual species. The researchers will share this separation technology broadly with other scientists in the microbial systematics, diversity, and ecology communities to help accelerate research in these areas. An interactive outreach module will be developed and brought to K-12 students to help spark appreciation for science, technology, and engineering research. This project will develop a method using dielectrophoresis to separate microbial communities based on morphotypes. Dielectrophoresis is the movement of uncharged particles in an electric field. Particles of similar size, shape, and surface characteristics move in similar ways and are expected to accumulate in the same compartment of a gated microscopic channel once an electrical field is applied. This approach will advance the fields of microbial systematics and biodiversity science by enabling scientists to link morphological and molecular biodiversity in understudied microbial communities. The separation device will be used to answer two main questions about the evolution of symbiotic, wood-digesting protozoa that live in termite hindguts. First, how did the ancestor of termite hindgut protozoa acquire the ability to digest wood? For this project, tens of thousands of cells from key protozoan species will be separated from the rest of their communities for transcriptome sequencing. Genes for wood digesting enzymes will be identified and phylogenetically analyzed along with related genes from other organisms. Second, have protozoan symbionts transferred from one termite species to another in the genus Zootermopsis? And if so, can this explain the greater diversity of protozoa relative to their hosts? For this project, the hindgut communities of four Zootermopsis species will be separated into their constituent species in order to determine how many protozoan species are present and how closely they are related to one another. This information will be compared to the phylogeny and biogeography of Zootermopsis termites to determine whether and when such transfers may have occurred.