This work at hand deals with two monosaccharides, beta-D-mannuronic acid (M) and alpha-L-guluronic acid (G), units of bacterial and algal alginates. Bacterial alginates are metabolic products of particular species of bacteria. They are thought to be the main structural components of biofilms, and play an important role in water technology. Water-soluble alginates chains build a 3-dimensional network with calcium ions. The goal of this work was to understand how the monomers of bacterial alginate interact with calcium ions to build this network. This was examined with theoretical models, i. e. forcefield calculations with molecular dynamics simulations