Induction of an axenic filamentous-like callus growth from the brown algae Fucus vesiculosus is described. Preliminary identification of surface symbionts depending on 18S ribosomal RNA revealed the presence of a tremendous number of microorganisms (e.g., Aplanochytrium sp., other uncultured stramenopile). Therefore, different chemical, physical and mechanical treatments were investigated in different combinations to develop axenic unialgal cultures. Moreover, viability was confirmed by the enzymatic reduction of 2,3,5-triphenyl tetrazolium chloride which demonstrated an average vitality of 29%, relative to non-sterilized explants. After six weeks of a phototrophic cultivation on ASP-12-NTA supplemented with 0.5% w/v agar, a filamentous callus-like growth was observed, which was identified genetically through its mitochondrial DNA. Achievement of such marine callus cultures could open new chances in blue biotechnology for axenic cultivation of macroalgae and the production GMP-compliant marine bioactive compounds like fucoidan.

A. Zayed, M. Kovacheva, K. Muffler, H.-W. Breiner, T. Stoeck, R. Ulber; Induction and Genetic Identification of a Callus-Like Growth Developed in The Brown Alga Fucus vesiculosus; Engineering in Life Sciences, doi.org/10.1002/elsc.201800211