Industrial biotechnology is concerned with the sustainable production of, forexample, fine and bulk chemicals, pharmaceuticals and proteins by utilizingmicroorganisms for the conversion of renewable carbon sources. Well known examplesinclude the production of amino acids by Corynebacterium glutamicum at a million tonscale per year worldwide, or the recombinant production of insulin by Escherichia coli.Growth and productivity of the underlying host microorganisms are two keyperformance indicators in biotechnological production processes. Assuming isogenicstarting populations, optimal reactor control and mixing, a uniform cell behavior duringgrowth might be expected. However, as confirmed in recent years, isogenic bacterialpopulations can be physiologically heterogeneous. Obviously, there is a strong demandto unravel microbial population heterogeneity, understand its origin and gain knowledgeon its impact on large scale biotechnological production. Therefore, new analyticaltechniques addressing single-cell behavior are the key for further optimization.In particular, state-of-the-art microfluidic cultivation systems facilitating single-cellresolution and accurate environmental control over long time periods at the same time,offer completely new experimental assays on microbial populations. In contrast toconventional systems, for example, fluorescence activated cell sorting, microfluidiccultivations enable the analysis of cell dynamics by automated time-lapse microscopywith full spatio-temporal resolution.The aim of the present thesis was to develop and establish a new microfluidicplatform technology for microbial single-cell analysis in order to address key concernson population heterogeneity and reactor inhomogeneity in industrial biotechnology.Several unique single-cell cultivation chips were successfully fabricated and validatedwith a variety of industrially applied microorganisms. Each device contained up to severalthousand micrometer sized cultivation structures in parallel intended for high-throughputanalysis of single cells and isogenic microcolonies
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