Production and molecular characteristics of four groups of exopolysaccharides from submerged culture of Phellinus gilvus

Abstract

Aims:The objective of the present study was to determine the optimal culture conditions for the production of four groups of exopolysaccharides (EPSs) in Phellinus gilvus by submerged culture and to investigate their molecular properties by multi-angle laser-light scattering (MALLS) analysis. Methods and Results: The optimal temperature and initial pH for the production of both mycelial biomass and EPSs in P. gilvus by submerged flask cultures were found to be 30°C and pH 9AE0, respectively. Glucose and corn steep powder were the most suitable carbon and nitrogen source for both mycelial biomass and EPS production. Optimal medium composition was determined to be glucose 30 g l )1 , corn steep powder 5 g l )1 , MgSO 4 1AE23 g l )1 , KH 2 PO 4 0AE68 g l )1 , and K 2 HPO 4 0AE87 g l )1 . Four groups of EPSs (Fr-I, II, III, and IV) were obtained from the culture filtrates by gel filtration chromatography on Sepharose CL-4B and characterized by size exclusion chromatography (SEC) coupled with MALLS. The weight average molar mass (M w ) of Fr-I, Fr-II, Fr-III and Fr-IV were determined to be 8AE628 · 10 6 (±129 420), 1AE045 · 10 6 (±19 855), 61AE09 · 10 4 (±1244), and 33AE55 · 10 4 (±134) g mol )1 , respectively. Conclusions: Under optimal culture conditions, the maximum EPS production in a 5-l stirred fermenter indicated 5AE3 g l )1 after 11 days of fermentation. The SEC/MALLS analysis revealed that Fr-I, which has extremely high molecular weight, was presumably an aggregate of complex polysaccharides forming a compact globular shape; whereas Fr-II was nearly spherical, Fr-III and Fr-IV were rod-like chains in an aqueous solution. Significance and Impact of the Study: This is the first report on the production of high amounts of EPSs from liquid-culture of the basidiomycete, P. gilvus. The SEC/MALLS approach used in this study could be useful in providing greater insight into the characterization of the mushroom polysaccharides without carrying out elaborate fractionation procedures prior to analysis.

Effects of cigarette smoke condensate on the production and characterization of exopolysaccharides by Bifidobacterium

“…Results for Fr-I indicated generally higher values of polydispersity ratio as compared to Fr-II, indicating that molecules of Fr-I are remarkably more dispersed in aqueous solutions when forming large aggregates with respect to Fr-II (Hwang et al 2003). The RMS radii for four peaks ranged from 14.1 to 30.8 nm with no clear trends.…”

“…The crude EPSs were collected by centrifugation at 8,000 g for 10 min discarding the supernatant. The precipitate of EPS was redissolved in distilled water and its concentration determined by the phenolsulfuric acid method (Hwang et al 2003). Acetic acid content was determined using a modified hydroxyl biphenyl assay according to the procedure of the Carbazole-sulfuric acid method (Vuyst et al 2001).…”

Effect of carbon source on production, characterization and bioactivity of exopolysaccharide produced by Phellinus vaninii Ljup

“…The total EPS in the culture medium was determined by the phenol-sulphuric acid method, using glucose as the standard (Dubois et al 1956). The dry weight of mycelium was measured after washing the mycelial pellet with distilled water three times and drying at 70 o C to a constant weight (Hwang et al 2003).…”

“…Fractions (5.0 ml/ tube) were collected by a fraction collector (Hwang et al 2003). The total carbohydrate content in the EPS was also determined by the phenol-sulfuric acid method (Hu et al 2014 HQ, JM Science Inc., Buffalo, NY) connected in series.…”

“…where r i is the RMS radius of an EPS molecule, M i is the molar mass of EPS, k is the intercept at the Y-axis (RMS radius), and 1/3, 1/2, and 1 are the critical slope values for determining the molecular conformation of each EPS (Hwang et al 2003, Lim et al 2005). …”