Controlled communication between physically separated bacterial populations in a microfluidic device

Ekaterina Osmekhina,Christopher Jonkergouw,Georg Schmidt,Sami Franssila,Markus B Linder,Farzin Jahangiri,Ville Jokinen

doi:10.1038/s42003-018-0102-y

Ekaterina Osmekhina, Christopher Jonkergouw + Show 5 more

Open Access

https://doi.org/10.1038/s42003-018-0102-y

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Journal: Communications Biology	Publication Date: Jul 20, 2018
Citations: 23	License type: open-access

Affiliation: Aalto University, Espoo Music Institute

Abstract

The engineering of microbial systems increasingly strives to achieve a co-existence and co-functioning of different populations. By creating interactions, one can utilize combinations of cells where each population has a specialized function, such as regulation or sharing of metabolic burden. Here we describe a microfluidic system that enables long-term and independent growth of fixed and distinctly separate microbial populations, while allowing communication through a thin nano-cellulose filter. Using quorum-sensing signaling, we can couple the populations and show that this leads to a rapid and stable connection over long periods of time. We continue to show that this control over communication can be utilized to drive nonlinear responses. The coupling of separate populations, standardized interaction, and context-independent function lay the foundation for the construction of increasingly complex community-wide dynamic genetic regulatory mechanisms.

Highlights

The engineering of microbial systems increasingly strives to achieve a co-existence and cofunctioning of different populations
We demonstrate how cellular communication leads to synchronized community-wide functions, both through external induction and by dynamic feedback loops
We constructed a polydimethylsiloxane (PDMS)-based microfluidic device, in which the growth of cells takes place in, and is confined to, a trapping chamber. This trapping chamber is divided into two parts by a filter made of rows of PDMS pillars and cellulose nanofibrils (CNFs)[22] entangled between them (Fig. 1a–d, Supplementary Fig. 1 and 2)

Summary

Introduction

The engineering of microbial systems increasingly strives to achieve a co-existence and cofunctioning of different populations. Attempts to prevent overgrowth have led to the design of cellular interdependencies, in which individuals produce essential metabolites necessary for the survival or growth of the other[5,17,18,19] These interdependencies are complicated to construct, can lead to a high metabolic burden, may interfere with other pathways, and show fluctuations of relative population sizes in the community. Setups used so far drastically reduce the efficiency of communication, delaying the responses of populations and cause a break in synchrony These methods face uneven growth and variations in expression rates, making the communication highly variable and time-dependent, as they have been difficult to implement as continuous systems[18,20,21]. A much needed tool in developing cellular communication within communities is a system in which the stable and independent function of each population can be studied and controlled over long periods of time, similar to the function of individual processors on a circuit board[21]

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