Methods

Every bac­terium, every mi­croor­gan­ism has its very own en­zymes – its own tools – in or­der to cut poly­sac­char­ides. We can use such en­zymes to meas­ure sugar mo­lecules in the sea. The bac­terial en­zymes are re­spons­ible for the break­ing down of sugar com­pounds. They break the large, com­plex poly­sac­char­ides into small, simple mono­sac­char­ide units. These simple sug­ars are easier to meas­ure than poly­sac­char­ides. More...

In focus are the en­zymes in­volved in the con­ver­sion of min­er­als and gases. They are pro­teins that or­ches­trate strange re­ac­tions highly chal­len­ging for chem­ists. We have to ex­tract these en­zymes, and sort them out from other pro­teins by us­ing the nat­ive puri­fic­a­tion. We then pierce the mo­lecu­lar secret of their re­ac­tion by look­ing at them with X-ray crys­tal­lo­graphy, which means that we have to crys­tal­lize the en­zymes, and use X-ray to get their pic­tures. More...

With the help of meta-genomics, it is possible to analyse an environmental sample (i.e. a mixture of the most diverse organisms as they live together in the environment) and find out which organisms live in this environment as well as which genes – and thus metabolic pathways, interactions, and defence strategies – predominate. More...

Mi­croor­gan­isms can barely be dis­tin­guished from each other based on their ap­pear­ance. Nev­er­the­less, every cell has its own fin­ger­print that is typ­ical for the spe­cies – its ge­netic ma­ter­ial. A case for FISH, Fluor­es­cence In Situ Hy­brid­isa­tion. It se­lect­ively visu­al­izes cer­tain sec­tions of the ge­netic ma­ter­ial of in­di­vidual cells. Un­der the mi­cro­scope, these cells are then made to glow. FISH im­ages of mi­croor­gan­isms look like a starry sky, but one with many dif­fer­ent col­ours. Our ques­tion is: What is shin­ing where? With FISH, we can pre­cisely identify the or­gan­isms in our samples. More...

We di­lute the cells with sterile sea­wa­ter dir­ectly after sampling to isol­ate in­di­vidual cells and in­cub­ate for long times to get slowly grow­ing bac­teria. The com­bin­a­tion of phys­ical isol­a­tion into hun­dreds of cul­tures, suf­fi­cient time to grow and mo­lecu­lar tools to ana­lyze en­rich­ment cul­tures still needs the per­fect me­dium for the mi­croor­gan­ism of in­terest. A per­fect me­dium provides all nu­tri­ents at non-toxic con­cen­tra­tions, ideally in a per­man­ent con­tinu­ous-fed mode at mi­cro­molar con­cen­tra­tion, like in nature. More...