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%0 Thesis
%A Hoffmann, Kyra
%T Online analysis of microbial γ-polyglutamic acid production and plant defense priming in small-scale cell culture
%I Rheinisch-Westfälische Technische Hochschule Aachen
%V Dissertation
%C Aachen
%M RWTH-2024-09757
%P 1 Online-Ressource : Illustrationen
%D 2024
%Z Veröffentlicht auf dem Publikationsserver der RWTH Aachen University
%Z Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2024
%X The development of online analytical tools significantly accelerates research of bioprocesses in small shaken cultures. This thesis demonstrates the application of online analytics for two processes. Firstly for the production of poly--glutamic acid (γ-PGA) in shake flasks and secondly for the detection of priming-active compounds with parsley cell cultures in microtiter plates. These two diverse research topics demonstrate the power of online analytic tools in small culture scale. The first chapter of this thesis is about the online screening of γ-PGA, a biopolymer with a wide range of applications. The γ-PGA was produced with genetically modified Bacillus subtilis 168 strains. The formation and concomitant secretion of γ-PGA increase the culture broth viscosity, while enzymatic depolymerization and degradation of γ-PGA by native depolymerases decrease the viscosity. The viscosity monitoring online system (ViMOS) was applied for optical online measurements of broth viscosity in shake flasks. This online monitoring enabled the analysis of the promoter Ppst in combination with different γ PGA depolymerase and by-product knockout mutants in genetically modified B. subtilis 168 strains. The different single depolymerase knockout mutants were ∆ggt, ∆pgdS, ∆cwlO, and a triple knockout mutant. Additionally, to the Ppst promoter, the γ-PGA production under the control of the Pxyl promoter was analyzed. An increase in γ-PGA yield in gγ PGA/gglucose of 190
%F PUB:(DE-HGF)11
%9 Dissertation / PhD Thesis
%R 10.18154/RWTH-2024-09757
%U https://publications.rwth-aachen.de/record/995158