Statistical experimental design optimization of rhamsan gum production by Sphingomonas sp. CGMCC 6833

Abstract

Rhamsan gum is a type of water-soluble exopolysaccharide produced by species of Sphingomonas bacteria. The optimal fermentation medium for rhamsan gum production by Sphingomonas sp. CGMCC 6833 was explored definition. Single-factor experiments indicate that glucose, soybean meal, K(2)HPO(4) and MnSO(4) compose the optimal medium along with and initial pH 7.5. To discover ideal cultural conditions for rhamsan gum production in a shake flask culture, response surface methodology was employed, from which the following optimal ratio was derived: 5.38 g/L soybean meal, 5.71 g/L K(2)HPO(4) and 0.32 g/L MnSO(4). Under ideal fermentation rhamsan gum yield reached 19.58 g/L ± 1.23 g/L, 42.09% higher than that of the initial medium (13.78 g/L ± 1.38 g/L). Optimizing the fermentation medium results in enhanced rhamsan gum production.

Rheological studies of the fucose-rich exopolysaccharide FucoPol

“…Examples of commercial bacterial polysaccharides include xanthan gum, gellan gum, fucogel, hyaluronic acid and welan gum. Others, with either none or low commercial expression have been reported, for example colanic acid [8], clavan [9] and rhamsan [10]. Beyond the solution properties, they may also present interesting biological activities, namely those composed of l-fucose, l-rhamnose or uronic acids residues.…”

An efficient production of a novel carbohydrate polymer Sphingan WL

“…Carbon source is both one major constituent for the building of cellular materials and an energy source for polysaccharide synthesis; therefore, it has a significant influence on the synthesis of EPSs . In this study, the effects of 14 different carbon sources including monosaccharides and sugar alcohols (fructose, mannitol, sorbitol, xylose, arabinose, glucose, and galactose), disaccharides (maltose, lactose, and cellobiose), trisaccharide (raffinose) and polysaccharides (glucan T5, starch, and cellulose) at a concentration of 40 g L −1 were investigated (Fig.…”

“…It has been reported that Sphingomonas sp. CGMCC 6833 and Sphingomonas sanxanigenes strain NX02 optimally metabolize glucose as their carbon source to produce rhamsan gum and the sphingan Ss . Different from the Sphingomonas sp.…”

“…To date, RSM has been proved to be very useful for the optimization of the production of some sphingans, such as welan and rhamsan gum; however, the reason underlying the observed enhancement in production has rarely been investigated due to the complicated nature of the related biosynthetic pathways. Metabolic flux analysis (MFA) has been used to predict changes in the fluxes of metabolic pathways and was thus utilized to elucidate the possible reason(s) for the observed increase in welan gum production; however, this method does not provide direct evidence for the synthesis process.…”

Influence of the Homogenization Pressure on the Rheology of Biopolymer-Stabilized Emulsions Formulated with Thyme Oil

“…The most-used polysaccharides are xanthan and guar gum. However, there are some new ones that have recently attracted much attention, such as welan and rhamsan gums [5][6][7].…”