Effect of different media on exopolysaccharide and biomass production by the green microalga Botryococcus braunii

Absorption and scattering by fractal aggregates and by their equivalent coated spheres

“…(17). Moreover, the orientation-averaged absorption 〈C a abs;RDG 〉 and scattering 〈C a sca;RDG 〉 cross-sections and the scattering phase function F 11;RDG ðΘÞ of the aggregates were predicted by the RDG approximation using Eqs.…”

“…This species secretes exopolysaccharides (EPS), a viscous substance coating the cell surface and causing their aggregation into colonies. EPS production is part of a protection mechanism activated in response to environmental conditions such as limited Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jqsrt illumination [15], non-optimal temperature [16], high salinity [16], and limited nutrient availability [17]. In addition, a recent study demonstrated reversible cell aggregation in concentrated Chlorella vulgaris cultures used for protein, starch, and lipid production [18].…”

Botryococcus braunii for the production of hydrocarbons and exopolysaccharides and the role of associated bacteria

“…Other monomeric composition of the total carbohydrates shows galactose and glucose as the main monomers across all strains. For CCALA777 and CCALA778 galactose is by far the largest fraction of the carbohydrates moieties and is presumably the reason why viscosity increases (Fernandes et al 1989, Allard and Casadevall 1990, Díaz Bayona and Garcés 2014. Recent work shows that galactose can be used for the production of bioethanol via fermentation (Lee et al 2011, Park et al 2014, therefore with the high amounts of galactose produced by CCALA777 and CCALA778, these strains can be consider as potential candidates as raw material for the production of bioethanol.…”

“…EPS from B. braunii contains fucose and uronic acids, which have potential applications such as cancer treatment or reduction of metal-associated toxicity in wastewater, respectively (Wijesinghe andJeon 2012, Díaz Bayona andGarcés 2014). As many other B. braunii strains, CCALA778 shows the presence of a diverse range of bacteria cohabiting with the microalgae but their role or function are unknown (Fernandes et al 1989).…”

“…Some strains of B. braunii can produce up to 86 % hydrocarbons on biomass dry weight basis (Brown et al 1969), whereas the carbohydrate producing strains can produce to up to 4.5 g L -1 of EPS into the medium (Fernandes et al 1989, Lupi et al 1994, Dayananda et al 2007, Díaz Bayona and Garcés 2014. The EPS from B. braunii is mainly composed of galactose and minor quantities of other sugars as fucose, rhamnose, glucose and uronic acids residues (Fernandes et al 1989, Allard and Casadevall 1990, Díaz Bayona and Garcés 2014.…”