ISBN 9783843944083

978-3-8439-4408-3, Reihe Biochemie

Johannes Christoph Nolte
Screening and characterization of biocatalysts for the glycosylation of natural products

207 Seiten, Dissertation Universität Köln (2020), Softcover, A4

Zusammenfassung / Abstract

Glycosylation can significantly increase the stability and water solubility of natural products and their derivatives. The overall aim of this thesis was to establish the enzymatic glycosylation of biologically active natural products. The application of glucansucrases, which are members of the GH70 enzyme family, is particularly interesting since these enzymes utilize low-priced sucrose as the glycosyl-donor and are principally able to perform natural product glycosylation. The lactic acid bacteria genera Leuconostoc and Weissella are known to comprise several glucansucrase-producing strains and are hence promising resources for the identification of novel and so far uncharacterized enzymes. From a set of 41 different bacterial strains, nineteen strains possessing active glucansucrases were identified. Beside glucansucrase activity in soluble secreted form, most strains also exhibited cell-associated enzyme activity. Studies with the catecholic model acceptor compounds caffeic acid, (+)-catechin and nordihydroguaiaretic acid (NDGA) revealed that natural product glycosylation is not only limited to a few enzymes but a widespread characteristic of Leuconostoc and Weissella glucansucrases in general.