The structure of the capsular polysaccharide produced from the type strain of Agrobacterium rubi DSM 6772 is demonstrated by means of chemical and spectroscopical methodologies. It is constituted from the quite rare monosaccharide 6-deoxy-L-talose, involved in alternating alpha-(1 -> 2) and alpha-(1 -> 3) linkages. This simple backbone is further complicated from the occurrence of O-acetyl substituents located always at O-2 of the O-3 substituted 6-deoxy-talose. This decoration is not stoichiometric and it depends on the growth stadium of the bacterium, leading to an almost regular acetylation pattern only at the stationary phase, where all the potential positions are substituted.