Network structure and functional properties of transparent hydrogel sanxan produced by Sphingomonas sanxanigenens NX02

•The network structure of sanxan mainly contained side-by-side connection type.•The transparent sanxan exhibited a gelation character.•Gel strength of sanxan was enhanced in the presence of cations or gellan.•Sanxan formed stable emulsions with various oils and hydrocarbons.•Possible application of sanxan in food and cosmetic industries. The micro-network structure and functional properties of sanxan, a novel polysaccharide produced by Sphingomonas sanxanigenens NX02, were investigated. Transparent hydrogel sanxan was a high acyl polymer containing 8.96% acetyl and 4.75% glyceroyl. The micro-network structure of sanxan was mainly cyclic configurations composed of side-by-side intermolecular associations, with many rounded nodes found. Sanxan exhibited predominant gelation behavior at concentrations above 0.1%, which was enhanced by adding cations, especially Ca2+. The gel strength of sanxan was much higher than that of low acyl gellan, but slightly lower than that of high acyl gellan. Furthermore, the conformation transition temperature was increased in the presence of added cations. Moreover, sanxan showed excellent emulsifying and emulsion stabilizing properties. Consequently, such excellent functional properties make sanxan a good candidate as a gelling, stabilizing, emulsifying, or suspending agent in food and cosmetics industries, and in medical and pharmaceutical usage.