(→3)-β-D-Glcp(1→4)-β-D-GlcpA(1→4)-β-D-Glcp(1→4)-α-L-Rhap(1→). 0.5 O-acetyl group per repeating unit on the first glucose unit at C(6) . O-L-glycerate on the first glucose unit at C(2) . Gellan also has poly(β-hydroxybutyrate) subunits . Exists in solution as a left-handed threefold parallel double helix [3,5]. At high temperatures gellan molecules are disordered, while cooling the solution results in an ordered and elongated conformation which is thermally reversible .