Microsegmented flow-assisted miniaturized culturing for isolation and characterization of heavy metal-tolerant bacteria
Soils are complex ecosystem, and their function in the environment is mainly determined by the microbial communities. Metal-tolerant micro-organisms have an important function in the formation of soil and the development of microbial communities in all areas where heavy metals are released by natural erosion processes or by human activities. The investigation of dose-dependent growth and behaviour is an essential part of the search for heavy metal-tolerant microorganism communities and their characterization. In this study, next-generation sequencing was used for the analysis of soil sample and reduced communities and droplet-based microfluidics was used to assess the growth behaviour of unknown bacterial communities and single strains in response to different heavy metal ions. Highly resolved dose–response functions of the bacterial communities reflect the specific character in their concentration-dependent response to different culture media and heavy metals of copper, nickel and cobalt. Besides the characterization of community responses, they allowed to characterize newly isolated strains. Concentration-dependent growth patterns of the micro-organisms in the droplets could be observed. The investigation demonstrates the potential of droplet-based microfluidics for miniaturized eco-toxicological studies and their suitability for the discovery of novel strains with special tolerance features.
KeywordsDroplet-based microfluidics Soil microbial communities Segmented flow Heavy metal tolerance Next-generation sequencing Dose–response
The authors acknowledge the financial support by the German Federal Ministry of Education and Research within the framework of Bactocat (Project Number 031A161A). We thank Karin Martin, Martin Roth (HKI Jena) and Erika Kothe (FSU Jena) for stimulating discussions on miniaturized screenings for soil bacteria.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interests.
- Cao JL, Kursten D, Krause K, Kothe E, Martin K, Roth M, Kohler JM (2013) Application of micro-segmented flow for two-dimensional characterization of the combinatorial effect of zinc and copper ions on metal-tolerant Streptomyces strains. Appl Microbiol Biot 97:8923–8930. https://doi.org/10.1007/s00253-013-5147-8 CrossRefGoogle Scholar
- Gupta K, Chatterjee C, Gupta B (2012) Isolation and characterization of heavy metal tolerant Gram-positive bacteria with bioremedial properties from municipal waste rich soil of Kestopur canal (Kolkata), West Bengal, India. Biologia 67:827–836. https://doi.org/10.2478/s11756-012-0099-5 CrossRefGoogle Scholar
- Kursten D, Moller F, Gross GA, Lenk C, Visaveliya N, Schuler T, Kohler JM (2015) Identification of response classes from heavy metal-tolerant soil microbial communities by highly resolved concentration-dependent screenings in a microfluidic system. Methods Ecol Evol 6:600–609. https://doi.org/10.1111/2041-210x.12344 CrossRefGoogle Scholar
- Langelüttich H-J, Mirsch R, Knitzschke G, Roloff P, Spilker M, Wordelmann H (1999) Bergbau auf Kupferschiefer. In: Roloff P (ed) Die Geschichte des Berg- und Hüttenwesens. Verein Mansfelder Berg- und Hüttenleute, Mansfeld, pp 41–204Google Scholar