Model of interaction between lipase A and alginate from P . aeruginosa . Left: Lipase protein in presence of an inhibitor molecule in the active centre of the enzyme . Furthermore, the co-factor molecule Ca2+ is indicated in green. Site chains of positively charged amino acids are shown in blue. Right: Section of an alginate molecule composed of negatively charged uronic acids in ball and stick representation. For better visibility the water in the reaction room is not shown (Redrawn from ).