Dutschei, Theresa
[Verfasser:in]
;
Bornscheuer, Uwe Theo
[Akademische:r Betreuer:in];
Streit, Wolfgang R.
[Akademische:r Betreuer:in]Universität Greifswald
Enzymatic elucidation of carbohydrate utilization in marine Bacteroidetes
Marine algae are essential for fixation of carbon dioxide, which they transform into complex polysaccharides. These carbohydrates are degraded e.g., by marine Bacteroidetes and the understanding of their decomposition mechanism can expand our knowledge how marine biomasses can be accessed. This understanding then gains insights into the marine carbon cycle. This thesis summarizes the current knowledge of marine enzymatic polysaccharide degradation in review Article I and extents a previously discovered ulvan degradation pathway in Article II with the description of a novel dehydratase involved in the ulvan degradation pathway. This enlarged ulvan-degradation pathway can be used to generate fermentable sugars from the algal derived polysaccharide ulvan. A potential biorefinery process is proposed in Article III, where B. licheniformis was engineered to degrade ulvan, thus establishing the initial steps for a microbial cell factory development. In addition to ulvan, also plenty of other complex carbohydrate sources are present in the ocean. The enzymatic elucidation principles previously developed were thus adapted towards a new marine carbohydrate. In Article IV a xylan utilization pathway was elucidated, using enzymes present in Flavimarina Hel_I_48 as model bacterium. The Flavimarina genome contains two separated genome clusters which potentially targets xylose containing polymers reflecting the diversity and adaptions towards different marine xylan-like substrates. Besides, ...