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Fomitiporia species have aroused the interest of numerous investigations that reveal their biological activity and medicinal potential. The present investigation shows the antioxidant, anticancer, and immunomodulatory activity of acidic polysaccharides obtained from the fungus Fomitiporia chilensis. The acidic polysaccharides were obtained for acidic precipitation with 2% O-N-cetylpyridinium bromide. Chemical analysis was performed using FT-IR and GC-MS methods. The antioxidant capacity of acidic polysaccharides from F. chilensis was evaluated by scavenging free radicals with an ABTS assay. Macrophage proliferation and cytokine production assays were used to determine the immunomodulatory capacity of the polysaccharides. Anti-tumor and cytotoxicity activity was evaluated with an MTT assay in the U-937, HTC-116, and HGF-1 cell lines. The effect of polysaccharides on the cell cycle of the HCT-116 cell line was determined for flow cytometry. Fourier Transform-infrared characterization revealed characteristic absorption peaks for polysaccharides, whereas the GC-MS analysis detected three peaks corresponding to D-galactose, galacturonic acid, and D-glucose. The secreted TNF-α concentration was increased when the cell was treated with 2 mg mL−1 polysaccharides, whereas the IL-6 concentration was increased with all of the evaluated polysaccharide concentrations. A cell cycle analysis of HTC-116 treated with polysaccharides evidenced that the acidic polysaccharides from F. chilensis induce an increase in the G0/G1 cell cycle phase, increasing the apoptotic cell percentage. Results from a proteomic analysis suggest that some of the molecular mechanisms involved in their antioxidant and cellular detoxifying effects and justify their traditional use in heart diseases. Proteomic data are available through ProteomeXchange under identifier PXD048361. The study on acidic polysaccharides from F. chilensis has unveiled their diverse biological activities, including antioxidant, anticancer, and immunomodulatory effects. These findings underscore the promising therapeutic applications of acidic polysaccharides from F. chilensis, warranting further pharmaceutical and medicinal research exploration.

Anthropogenic impacts on water resources, especially by ​​nutrient discharge, is a worldwide problem in marine coastal areas. In this context, seaweed cultivation in aquaculture wastewater can be considered as an alternative for effluent mitigation, where the biomass becomes a source of valuable compounds. The current study examined the potential use of the seaweeds Ulva pseudorotundata and Ulva rigida to remove nutrients to treat effluents from the culture of Chelon labrosus. Two experiments were conducted under pilot-scale conditions to evaluate the nutrient uptake, photosynthetic activity, and biomass production of the seaweed species cultivated under 50 and 100% effluent concentrations. Photosynthetic parameters were determined by in vivo chlorophyll a fluorescence associated to photosystem II 3 times a day to estimate photosynthetic performance and seaweed physiology throughout the experiment: optimal quantum yield (Fv/Fm), in situ and ex situ electron transport rate (ETR), photosynthetic efficiency (αETR), saturation irradiance (Ek), and the maximum non-photochemical quenching (NPQmax). To evaluate seaweed metabolism and biomass compounds, elemental and biochemical composition were analyzed in the beginning and end of each experiment. Results regarding the nutrient source showed that both species removed more than 65% of ammonium after 3 hours of experimentation. At the end of the experiments, up to 94.8% of the initial ammonium was sequestered from the effluent. Additionally, after 5 days of cultivation under 50% fish effluent both Ulva species were able to remove more than 85% of the nitrate. Although a decrease in uptake efficiency was observed in cultures with 100% fish effluent, at the end of the experiment more than 440 µmol L-1 of nitrate was removed, considering all treatment conditions. The biomass values showed that growth rates of seaweed cultivated in 100% effluent were higher than those obtained in 50% effluent. Moreover, when cultivated in the 100% effluent concentration, a significant increment in protein content was detected in both Ulva species. Our results contribute to the understanding of biofiltration and photosynthetic performance of two different Ulva species in order to improve growth optimization, enhancement of biofiltration capacity and also to boost management practices of seaweed cultivation in aquaculture effluent treatment systems.

Sarcopeltis skottsbergii is an endemic species of the southern region of South America, with R-phycoerythrin (R-PE) as an accessory photosynthetic pigment. The production of S. skottsbergii is around twenty thousand tons of dry alga per year. The evaluation of (R-PE) in a biorefinery model is still incipient in the algal biotechnology area and will be used in the food, pharmaceutical, cosmeceutical, and nutraceutical industries. This work evaluated the cell disruption and separation processes by using two green technologies, ultrasound-assisted extraction (UAE) and high-pressure homogenization (HPH), to obtain an R-phycoerythrin enriched extract from S. skottsbergii. Two-levels three-factor central composite design (CCD) and response surface methodology (RSM) were carried out to optimize the extraction conditions, including the factors for UAE (time, amplitude, and solvent) and HPH (Pressure, number of passes, and solvent). Additionally, a second-order polynomial fit was performed to fit the experimental data by the green method. HPH method was the most efficient extraction method under the conditions obtained of 100-400 MPa pressure power, 2-3 number of passes, and distilled water as solvent. Furthermore, the experimental extraction yields ranged from 4.4-5.7 mg of PE g-1 of dry biomass under the optimal extraction conditions (400 MPa; 2 passes), which agreed with the predictive yield of 4.6-5.5 mg g-1 DW. The ultrafiltration membrane used for the separation process for both methods exhibited a rejection of R-phycoerythrin concentrated at 30 KDa. Furthermore, R-phycoerythrin showed a positive correlation between the antioxidant capacity (ORAC) in the best-selected extractions. After the extraction, the same pattern was observed in Chlorophyll a and total carotenoids with DPPH. Thus, it was an attractive non-aggressive extraction alternative with biological activity of interest for formulating biotechnological products for the food industry is suggested.