Sphingans and poly(R-3-hydroxybutyrate) (PHB) are both widely used biopolymers produced by bacteria. In the batch fermentation of Sphingomonas sanxanigenens NX02 in a 5L fermenter using glucose as carbon source, ivory colored sphingan Ss production was a growth-associated process with a maximum purified production of 14.88 ± 0.83 g/L, while 6.08 ± 0.23 g/L PHB was simultaneously produced. Sphingan Ss and PHB were separated by a simple dilution, heating and centrifugation or filtration process, and sphingan Ss can be cost-effectively extracted using a small amount of acid rather than multi-fold volumes of alcohols. From ultrathin sections of S. sanxanigenens NX02, we found that the interior space of the cells was filled with PHB granules, and the outside was surrounded by abundant Ss. The purified sphingan Ss can be used as an excellent gelling and emulsifying agent in biotechnology applications such as food, personal care and production processes. Proposed pathways of Ss and PHB biosynthesis from glucose are also presented.
Keywords: Poly(R-3-hydroxybutyrate); Simultaneous production; Sphingan Ss.
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