Carbon Sequestration and Glycobiochemistry

Con­gra­tu­la­ti­on to Nadine Gerlach, who suc­cess­ful­ly de­fen­ded her doc­to­ral the­sis with the tit­le "Macroalgae polysaccharides- a bittersweet feast for ma­ri­ne bac­te­ria"

We wish our two succesful PhDs students Agata Mystkowska and Stefan Becker all the best in their new jobs as Science and Innovation Manager at mk2 Biotechnologies in Munich (Germany) and Scientist Bioconjugates at Lonza in Visp (Switzerland).

Plant species‐specific recognition of long and short β‐1,3‐linked glucans is mediated by different receptor systems (Link).

A marine bacterial enzymatic cascade degrades the algal polysaccharide ulvan (Link).

Congratulation to Agata Mystkowska, who successfully defended her doctoral thesis with the title "Carbohydrate-binding proteins from marine bacteria".

Jan-Hendrik Hehemann is going to give a talk at the 8th Congress of European Microbiologists (FEMS2019), which will take place from July 7-11 in Glasgow, Scotland. He will also talk at the Gordon Research Conference on Carbohydrate-Active Enzymes for Glycan Conversions, which will take place from July 21-26 at the Proctor Academy in Andover, New Hampshire, United States.

For three days our group retreated to the island of Spiekeroog, in the western part of the German Bight, one of our main research areas. We discussed the future directions of our scientific work and the local ecosystem was explained to us in detail by the educators at the Nationalpark-Haus Wittbülten.

Single cell fluorescence imaging of glycan uptake by intestinal bacteria (Link).

FGB1 and WSC3 are in planta‐induced β‐glucan‐binding fungal lectins with different functions (Link)

Specificity and mechanism of carbohydrate demethylation by cytochrome P450 monooxygenases (Link)

In this study, we characterized a surface protein, GMSusD from the planktonic Bacteroidetes‐Gramella sp. MAR_2010_102 that thrives during algal blooms. Our biochemical and structural analyses show that GMSusD binds glucose polysaccharides such as branched laminarin and linear pustulan. We queried metagenomes of global surface water datasets for the occurrence of SusD‐like proteins and found sequences with the three structurally conserved residues in different locations in the ocean. Our findings provide insight into the molecular details of β‐glucan binding by GMSusD and our bioinformatic analysis reveals that this molecular interaction may contribute to glucan cycling in the surface ocean (Link).

Nicole Koropatkin (UMich) and Jan-Hendrik Hehemann chaired the first session on the 'Importance of glycobiology in microbial interactions' at the 17th conference of the International Society for Microbial Ecology in Leipzig, Germany. Invited speakers were Otto X. Cordero (MIT) and Mario Murakami (CNPEM).

• Biphasic cellular adaptations and ecological implications of Alteromonas macleodii degrading a mixture of algal polysaccharides (Link)

• Polysaccharide utilization loci of North Sea Flavobacteriia as basis for using SusC/D-protein expression for predicting major phytoplankton glycans (Link)

For three days our group retreated to the island of Norderney, in the western part of the German Bight, one of our main research areas. We discussed the future directions of our scientific work. Besides, we took windsurfing lessions and explored the island by bike.

In this study, we use environmental proteomics and metagenomics in combination with cultivation experiments and biochemical characterizations to investigate the molecular details of in situ polysaccharide degradation mechanisms during microalgal blooms. We show that highly specialized bacterial strains of the Bacteroidetes phylum repeatedly reached high abundances during North Sea algal blooms and dominated laminarin turnover. It was revealed that genome reduction, enzyme fusions, transporters and enzyme expansion, as well as a tight coupling of carbon- and nitrogen metabolism provide the tools, which make Formosa spp. so competitive during microalgal blooms (Link).

Congratulation to Stefan Becker, who successfully defended his doctoral thesis with the title "Biocatalytic quantification of laminarin - a major carbohydrate polymer in the ocean".

Congratulation to Nadine Gerlach, who won the third poster prize during the 15th edition of the Summer Course Glycosciences in Wageningen (Netherlands) for her poster on the "Molecular enzymatic recycling of sulfated algal polysaccharides by marine microbes"

Biochemical characterization of an ulvan lyase from the marine flavobacterium Formosa agariphila KMM 3901 (Link)

In the spirit of the open science movement and in order to further promote its application, we published an easy-to-use protocol of our method paper from 2017 (Link) on the open-access platform Bio-Protocol (Link).

New publication in the Journal of Bacteriology (Link).

Jan-Hendrik Hehemann is going to give a talk at the Gordon Research Conference on Organic Geochemistry, which will take place from July 29 to August 3 at the Holderness School in Holderness, New Hampshire, United States

The discovery of a new class of sugar demethylating enzymes from the P450 cytochrome monooxygenase family defines a mechanism to enhance bacterial agar degradation (Link).

At 5th January 2018, Jan-Hendrik Hehemann is going to give a talk at the University of Victoria, British Columbia, Canada

Crystal structure of a marine glycoside hydrolase family 99‐related protein lacking catalytic machinery (Link)

For three days our group retreated to the island of Neuwerk, in the middle of the Wadden Sea National Park in the German Bight, one of our main research areas. We had fruitful discussions and were able to explore the Wadden Sea on foot.

The Hehemann Lab is taking part in the POMPU research project together with our partners at the Ernst-Moritz-Arndt-Universität in Greifswald, the Max Planck Institute for Marine Microbiology in Bremen and the Alfred-Wegener-Institute for Polar and Marine Research in Helgoland. The DFG research unit FOR 2406 (Proteogenomics Of Marine Polysaccharide Utilization (POMPU)) is working on mechanisms of bacterial polysaccharide utilization during marine phytoplankton blooms. Our task is the functional analysis of glycan-binding proteins and glycan transporters (Subproject A3). Link

Aquatic adaptation of a laterally acquired pectin degradation pathway in marine gammaproteobacteria (Link)

In our recent study (Link) we described two enzymes that are used for the fast, stereo and sequence specific analysis of laminarin in marine organic matter. The respective plasmid are now available at the Addgene plasmid repository. FaGH17A is a highly specific endo-β-1,3-glucanase hydrolyzing the β-1,3 glucose backbone of laminarin (Link), whereas FbGH30 is an exo-β-1,6-glucanase that removes the β-1,6-glucose side chains (Link).

February 2017: Marine algae produce varieties of glycans, which fulfill diverse biological functions and fuel the carbon and energy demand of heterotrophic microbes. However, the common approach to analyze marine organic matter using acid to hydrolyze its glycans into measurable monosaccharides does not distinguish between glycans in natural samples. Stefan Becker and colleagues developed a method to selectively digest and thereby quantify laminarin in particulate organic matter by using carbohydrate active enzymes from marine Flavobacteria. The results demonstrate the potential of enzymes as toolkits for faster, stereo and sequence specific analysis of select glycans in marine organic matter. (https://doi.org/10.1128/AEM.03389-16)