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UID:UW-Physics-Event-2121
DTSTART:20110214T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260307T052115Z
LAST-MODIFIED:20110210T195916Z
LOCATION:Forum room\, Wisconsin Institutes of Discovery
SUMMARY:Microbial Interaction Networks in Soil and in Silico\, Special
  Seminar\, Kalin H. Vetsigian\, Harvard University
DESCRIPTION:Soil harbors a huge number of microbial species interactin
 g through secretion of antibiotics and other chemicals. What patterns 
 of species interactions allow for this astonishing biodiversity to be 
 sustained\, and how do these interactions evolve? I used a combined ex
 perimental-theoretical approach to tackle these questions. Focusing on
  bacteria from the genus Streptomyces\, known for their diverse second
 ary metabolism and production of antibiotics\, I isolated 64 natural s
 trains from several individual grains of soil and systematically measu
 red all pairwise interactions among them. Quantitative measurements on
  such scale were never possible before. They were enabled by a novel e
 xperimental platform based on robotic handling\, a unique self-built s
 canner array and automatic image analysis. This unique platform allowe
 d the simultaneous capturing of ~15\,000 time-lapse movies of growing 
 colonies of each isolate on media conditioned by each of the other iso
 lates. The data revealed a rich network of strong negative (inhibitory
 ) and positive (stimulating) interactions. Analysis of this network an
 d the phylogeny of the isolates\, together with mathematical modeling 
 of microbial communities\, revealed that: 1) The network of interactio
 ns has three special properties: "balance"\, "bi-modality"\, and "reci
 procity"\; 2) The interaction network is fast evolving\; 3) Mathematic
 al modeling explains how rapid evolution gives rise to the three speci
 al properties through an interplay between ecology and evolution. Thes
 e properties are not a result of stable co-existence\, but rather of c
 ontinuous evolutionary turnover of strains with different production a
 nd resistance capabilities.
URL:https://www.physics.wisc.edu/events/?id=2121
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