Effect of brown algae metabolites on the synthesis of O-glycosyl hydrolases by bacteria degrading the thallus of Fucus evanescens

The effect of fucoidan, extractive substances from Fucus evanescens and the Laminaria cichorioides protein (an inhibitor of endo-1 -> 3-beta-D-glucanase) on the degradation of F. evanescens thallus and on the growth of bacteria involved in this process was studied. The complex of O-glycosyl hydrolases and the level of their enzymatic activity in bacteria cultivated under various conditions depended significantly on the composition of the growth medium. The highest taxonomic diversity was observed for bacteria isolated from the thallus degraded in the control medium (sea water). These bacteria were characterized by very low levels of activity of the enzymes degrading polysaccharides (fucoidan, laminaran, and pustulan). In the presence of 1 -> 3-beta-D-glucanase inhibitors, the taxonomic diversity of the microorganisms degrading F. evanescens thallus was decreased, and the activity of O-glycosyl hydrolases (particularly, of fucoidan hydrolases) was increased.