Microalgae as photosynthetic microorganisms are the source of valuable compounds such as proteins, carotenoids, lipids and carbohydrate polymers. Among the different phyla, Porphyridium as part of the red microalgae (Rhodophyta) are of high importance as producers of sulfated polysaccharides. As the name suggests these microalgae are typically red; however, Porphyridium sordidum has an olive-green color and was recently described as a putative exopolysaccharide producer. Exopolysaccharides (EPS) are sugars polymers excrete to the culture medium. In this study P. sordidum is evaluated for the first time in detail as newly described EPS producer in direct comparison to the already characterized EPS producer Porphyridium purpureum. The evaluation was performed on several aspects, such as morphological differences between the two strains followed by the comparison of the growth behavior, nit...

Porphyridium exopolysaccharides (EPSs), which contain sulfate and methyl groups, have a similar potential for use in multiple industrial applications as macroalgae counterparts but lack detailed characterization. For this reason, we produced 0.21 g L-1 of P. sordidum EPS and 0.17 g L-1 P. purpureum EPS, followed by a thorough rheological characterization in respect to their differences in monomer composition, sulfate concentrations and methyl patterns. Furthermore, the effect of NaCl and CaCl2 was evaluated, and the effect of high salinity media on the rheological properties of the biopolymers was analyzed. Both Porphyridium EPSs show a remarkable stability at high temperature and under the effect of monoand divalent cations, and high salinity cultivation medium, which was evidenced by the rheological properties of the EPS. This feature is not displayed by many carbohydrate polymers, mak...

BTEX aromatic hydrocarbons (benzene, toluene, ethylbenzene and xylene) are persistent and toxic pollutants from industrial activities and oil spills that significantly affect water and soil quality as well as human health. Given the limitations of physicochemical methods for the remediation of these contaminants, bioremediation, particularly through the use of microalgae such as Chlorella sp., emerges as an efficient and sustainable alternative due to its ability to biodegrade contaminating organic compounds and adapt to various environmental conditions. Hence, this study evaluated the efficiency of BTEX hydrocarbon biopurification using the microalgae Parachlorella kessleri, isolated and morphologically and molecularly characterized. Its growth kinetics were determined, obtaining an exponential phase of 120 hours, a specific growth rate μ=0.0230 h⁻¹ and a generation time G=30.15 h. ...