Yield and physicochemical properties of EPS from Halomonas sp. strain TG39 identifies a role for protein and anionic residues (sulfate and phosphate) in emulsification of n‐hexadecane

Abstract

In this study, we investigated the yield and physicochemical properties of the high molecular weight extracellular polymeric substance (HMW-EPS) produced by Halomonas sp. strain TG39 when grown on different types and ratios of substrates. Glucose (1% w/v) and a peptone/yeast extract ratio of 5.1 (0.6% w/v final concentration) yielded an EPS fraction (HMW-glucose) exhibiting the highest anionic activity (20.5) and specific emulsifying activity (EI24 = 100%) compared to EPS produced by cells grown on mannitol, sucrose, malt extract or no carbon source. The HMW-EPS fractions were capable of binding approximately 255-464 mg of methylene blue (MB) per gram of EPS, which represents the highest reported binding of MB by a bacterial EPS. A comparative evaluation of these properties to those of commercial hydrocolloids indicated that the combined effect of protein and anionic residues of the HMW-EPS contributed to its ability to emulsify n-hexadecane. Liquid chromatography revealed the HMW-glucose EPS to be a heterogeneous polymer with a polydispersity index of 1.8. This work presents evidence of a correlation between the anionic nature and protein content of bacterial EPS with its emulsifying qualities, and identifies EPS produced by strain TG39 as a high MB-binding bacterial sorbant with potential biotechnological application.

Effect of reactor surface on production of bacterial cellulose and water soluble oligosaccharides by Gluconacetobacter hansenii PJK

“…[7,8] besides its conventional use as a raw material in clothing, pulp, and the paper industry [9]. Similarly, microbial saccharides produced by many bacteria have potential applications in increasing the viscosity, and promoting adhesion and water retention properties [10].…”

Optimization of Cultural Conditions for Production of Exopolysaccaride by <i>Halomonas marina</i> HMA 103 under Batch-Culture

“…CRSS, acetate was the most efficient carbon source producing a fructoglucan polysaccharide (Poli et al, 2004), while Halomonas sp. TG39 yielded a high molecular weight extracellular polymeric substance (HMW-EPS) when grown on glucose (1% w/v) and a peptone : yeast extract ratio of 5:1 (Gutierrez et al, 2009).…”

Diversity and Production of Extracellular Polysaccharide by Halophilic Microorganisms

“…V3a' 59 was able to produce an EPS as potential biosurfactant, while Halomonas sp. strain TG39 60 produced an EPS with high uronic acid content and possessed specific binding capacity for Ca, Si, Fe, Mg, Mn and Al. EPS derived from members of the family Alteromonadaceae were low in viscosity and was capable of emulsifying hydrocarbons and binding of heavy metals.…”

“…TG39 was correlated with 100% emulsifying capacity of hexadecane. 60 Antioxidant activity of extracellular polysaccharides derived from halophilic strains is not common but recently, the extracellular polysaccharide of H. xianhensis SUR308 has been shown to exert 43 to 72% DPPH radical scavenging activity at concentrations ranging from 0.06 to 1 mg/mL. 63 The sulphated EPS from H. eurihalina H2-7 enhanced the unspecific proliferation of human lymphocytes in response to the presence of the anti-CD3 mononuclear antibody, 93 while that of H. stenophila (B100 and N12T) 74 blocked the growth of human T-lymphocyte tumours.…”

“…The, EPS from Halomonas sp. TG39 was capable of removing methylene blue at the rate of 464 mg/g of EPS 60 while removal of polycyclic aromatic hydrocarbons such as naphthalene, phenanthrene, fluoranthene, and pyrene was recorded by an EPS producing strain H. eurihalina H-28.…”