Real-time image processing for label-free enrichment of Actinobacteria cultivated in picolitre droplets.

Zang E*, Brandes S*, Tovar M, Martin K, Mech F, Horbert P, Henkel T, Figge MT, Roth M (2013) Real-time image processing for label-free enrichment of Actinobacteria cultivated in picolitre droplets. Lab Chip 13(18), 3707-3713, *authors contributed equally.

*equal contribution

Abstract

The majority of today's antimicrobial therapeutics is derived from secondary metabolites produced by Actinobacteria. While it is generally assumed that less than 1% of Actinobacteria species from soil habitats have been cultivated so far, classic screening approaches fail to supply new substances, often due to limited throughput and frequent rediscovery of already known strains. To overcome these restrictions, we implement high-throughput cultivation of soil-derived Actinobacteria in microfluidic pL-droplets by generating more than 600,000 pure cultures per hour from a spore suspension that can subsequently be incubated for days to weeks. Moreover, we introduce triggered imaging with real-time image-based droplet classification as a novel universal method for pL-droplet sorting. Growth-dependent droplet sorting at frequencies above 100 Hz is performed for label-free enrichment and extraction of microcultures. The combination of both cultivation of Actinobacteria in pL-droplets and real-time detection of growing Actinobacteria has great potential in screening for yet unknown species as well as their undiscovered natural products.

Leibniz-HKI-Authors

Susanne Brandes
Marc Thilo Figge
Karin Martin
Franziska Mech
Martin Roth
Miguel Angel Tovar Ballen
Emerson Zang

Identifier

doi: 10.1039/c3lc50572c

PMID: 23881253