title: Distributed classifier based on genetically engineered bacterial cell cultures.
abstract: We describe a conceptual design of a distributed classifier formed by a population of genetically engineered microbial cells. The central idea is to create a complex classifier from a population of weak or simple classifiers. We create a master population of cells with randomized synthetic biosensor circuits that have a broad range of sensitivities toward chemical signals of interest that form the input vectors subject to classification. The randomized sensitivities are achieved by constructing a library of synthetic gene circuits with randomized control sequences (e.g., ribosome-binding sites) in the front element. The training procedure consists in reshaping of the master population in such a way that it collectively responds to the "positive" patterns of input signals by producing above-threshold output (e.g., fluorescent signal), and below-threshold output in case of the "negative" patterns. The population reshaping is achieved by presenting sequential examples and pruning the population using either graded selection/counterselection or by fluorescence-activated cell sorting (FACS). We demonstrate the feasibility of experimental implementation of such system computationally using a realistic model of the synthetic sensing gene circuits.
authors.affiliation: BioCircuits Institute, ‡Department of Bioengineering, §Molecular Biology Section, Division of Biological Science, University of California San Diego , La Jolla, California 92093, United States.
authors.forename: Andriy
authors.initials: A
authors.lastname: Didovyk
authors.forename: Oleg I
authors.initials: OI
authors.lastname: Kanakov
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Ivanchenko
authors.forename: Jeff
authors.initials: J
authors.lastname: Hasty
authors.forename: Ramón
authors.initials: R
authors.lastname: Huerta
authors.forename: Lev
authors.initials: L
authors.lastname: Tsimring
mesh_terms: D000465:Algorithms; D058045:Artificial Cells; D001185:Artificial Intelligence; D001419:Bacteria / Q000235:genetics*; D015723:Gene Library; D053263:Gene Regulatory Networks; D005813:Genes, Synthetic; D005818:Genetic Engineering; D008957:Models, Genetic; D010363:Pattern Recognition, Automated; D058615:Synthetic Biology
keywords: chemical pattern recognition; consensus classification; distributed sensing; machine learning; microbial population engineering; synthetic circuits