Characterization of extracellular polymeric substances produced by micro-algae Dunaliella salina

Discipline of Marine Biotechnology and Ecology, Central Salt and Marine Chemicals Research Institute (CSMCRI), Council of Scientific and Industrial Research (CSIR), G.B. Marg, Bhavnagar 364021, Gujarat, India
Carbohydrate Polymers (Impact Factor: 4.07). 01/2011; 83(2):852-857. DOI: 10.1016/j.carbpol.2010.08.067

ABSTRACT Extracellular polymeric substances comprised of average molecule size 1264.354 μm, exhibited characteristic diffraction peaks at 6.025°, 9.675°, 22.775° and 28.475° with d-spacing 14.74755, 9.36297, 3.88747 and 3.11512 Å, respectively. EDX confirms the presence of sulphate (2.7%) and 1H NMR reveals uronic acid, primary amine, aromatic-compounds, halides, aliphatic alkyl and sulfides. EPSs were thermostable upto 270 °C with CIxrd 0.12 and CIDSC 0.18. The dynamic viscosity is significantly high at pH 3.0 and decreases concomitantly with shear rate, confirming pseudoplastic rheological property. MALDI TOF–TOF represents a series of masses in linear mode corresponding to mass of pentose and hexose with ions. The positive ion reflector mode exhibited low mass peaks (m/z) corresponding to oligosaccharide and higher peaks for polysaccharide consist of different ratio of pentose and hexose associated with ions. EPSs allow further exploration of D. salina as potential EPSs producer and make it a promising candidate for biotechnological and industrial exploitation.

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Available from: Avinash Mishra, Mar 28, 2014
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    • "The occurrence of sulfated polysaccharides in sea salt could have origin in the marine organisms such as seaweeds and invertebrates (Mestechkina and Shcherbukhin, 2010). However, sulfated polysaccharides were also reported in microorganisms such as microalgae, namely Dunaliella salina (Mishra et al., 2011), and halophilic bacteria (Arias et al., 2003), known to colonise saline soils, thus representing other potential sources. "
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    ABSTRACT: The present work investigates, for the first time, the presence of triacylglycerides, polysaccharides, and protein of 16 food grade sea salts. Triacylglycerides, obtained by Soxhlet extraction with n-hexane, and representing a median content of 1.5 mg/kg of dry salt, were mainly composed by palmitic (42.8 mol%), stearic (13.3), linolenic (12.5), oleic (12.0), and linoleic acid (9.1) residues. Also, a dialysis-based methodology was developed to isolate the polymeric material from sea salt in amounts to allow its characterisation. The polymeric material accounted for 144 mg/kg of dry salt, mainly composed by sulfated polysaccharides and also containing protein. Polysaccharides were rich in uronic acid residues (21 mol%), glucose (18), galactose (15), and fucose (13), whereas the protein was composed by the hydrophobic amino acids alanine (25 mol%), leucine (14), and valine (14). These biomolecules arise from the surrounding environment of saltpans. Their characterisation contributes to the pursuit of parameters of origin.
    Journal of Food Composition and Analysis 08/2015; 41. DOI:10.1016/j.jfca.2014.12.023 · 1.99 Impact Factor
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    • "Functional groups of purified EPS were determined using Fourier transformed infrared (FTIR) spectroscopy analysis. The pellet was prepared by pressing the mixture of EPS and KBr (1:100) into a mould and the FTIR spectrum was acquired in the 4000–400 cm −1 region with a resolution of 4 cm −1 using a GX FTIR system (PerkinElmer, USA) (Kavita et al., 2013; Mishra, Kavita, & Jha, 2011). "
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    ABSTRACT: Oceanobacillus iheyensis BK6, isolated from a marine natural biofilm, produced approximately 400 mg L-1 extracellular polymeric substances (EPS). FTIR analysis of the EPS revealed different functional groups (halide groups, uronic acid and saccharides). The GCMS showed that the extracellular polysacchrides comprised of mannose (47.78%), glucose (29.71%) and arabinose (22.46%). The molecular mass of the EPS was about 2.14 × 106 Da. It was thermally stable and showed pseudoplastic rheology and emulsifying activity (66.47 %). The EPS exhibited antibiofilm activity against a pathogenic strain of Staphylococcus aureus. This is the first report on the characterisation of EPS from the genus Oceanobacillus. The high viscosity, emulsifying properties and antibiofilm activity of EPS make it suitable for potential pharmaceutical and industrial applications.
    Carbohydrate Polymers 01/2014; 101:39-35. DOI:10.1016/j.carbpol.2013.08.099 · 4.07 Impact Factor
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    • "In fact it was reported earlier that the algae Dunaliella sp. (Avinash et al., 2011) that exist in the natural salt pan ecosystem provides glycerol and galactose for the halobacteria and thus the strain recorded maximal halocin in response to supplementation of galactose under laboratory conditions. In a similar fashion maximal growth rate and halocin activity by haloarchaeon Sech7a was observed in media supplemented with glycerol and yeast extract (Pasˇi et al., 2008). "
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    ABSTRACT: Halobacteria, members of the domain Archaea that live under extremely halophilic conditions, are often considered as dependable source for deriving novel enzymes, novel genes, bioactive compounds and other industrially important molecules. Protein antibiotics have potential for application as preserving agents in food industry, leather industry and in control of infectious bacteria. Halocins are proteinaceous antibiotics synthesized and released into the environment by extreme halophiles, a universal characteristic of halophilic bacteria. Herein, we report the production of halocin (SH10) by an extremely halophilic archeon Natrinema sp. BTSH10 isolated from salt pan of Kanyakumari, Tamilnadu, India and optimization of medium for enhanced production of halocin. It was found that the optimal conditions for maximal halocin production were 42 °C, pH 8.0, and 104 h of incubation at 200 rpm with 2% (V/V) inoculum concentration in Zobell's medium containing 3 M NaCl, Galactose, beef extract, and calcium chloride as additional supplements. Results indicated scope for fermentation production of halocin for probable applications using halophilic archeon Natrinema sp. BTSH10.
    Saudi Journal of Biological Sciences 04/2013; 20(2):205-12. DOI:10.1016/j.sjbs.2013.02.002 · 1.26 Impact Factor
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