Fucoxanthin is a carotenoid that exerts multiple beneficial effects on human health. However, reports comparing microalgae culture conditions and their effect on growth and fucoxanthin production are still limited. Isochrysis galbana and Phaeodactylum tricornutum cultures in different light (62.0, 25.9, 13.5, or 9.1 μmol photons m -2 s -1 ), mixing conditions (1 vvm aeration or 130 rpm agitation), and media compositions (F/2 and Conway medium) were studied for comparison of cellular growth and fucoxanthin production on F/2 medium. I. galbana showed a better adaptation to tested culture conditions in comparison with P. tricornutum, reaching 2.15 × 10 7 ±4.07×10 6 cells mL -1 and a specific growth rate (μ) of 1.12±0.05 day -1 under aerated conditions and 62.0 μmol photons m -2 s -1 light intensity. Fucoxanthin concentration was about 25 % higher in P. tricornutum cultures under 13.5 μmol photons m -2 s -1 light intensity and aerated conditions, but the highest fucoxanthin total production was higher in I. galbana, where 3.32 mg can be obtained from 1 L batch cultures at the 16th day under these conditions. Moreover, higher cell densities (~32.41 %), fucoxanthin concentration (~42.46 %), and total production (~50.68 %) were observed in I. galbana cultures grown in Conway medium, if compared with cultures grown in F/2 medium. The results show that the best growth conditions did not result in the best fucoxanthin production for either microalgae, implying that there is not a direct relationship between cellular growth and fucoxanthin production. Moreover, the results suggest that I. galbana cultures on Conway medium are strong candidates for fucoxanthin production, where 1.2 to 15 times higher fucoxanthin concentration are observed in comparison to macroalgal sources.

BACKGROUND: Fucoxanthin is a carotenoid that exerts multiple beneficial effects on human health, including antioxidant, anti-cancer, anti-diabetic and anti-obesity activity. In this study, the partition behavior of fucoxanthin in aqueous two-phase systems (ATPS) composed of ethanol and potassium phosphate was evaluated. This evaluation was performed 'en route' to establishing an ATPS extraction system for the recovery of fucoxanthin from microalgae cultures. System parameters including tie-line length (TLL), volume ratio (V R ) and product concentration were studied using model (purified fucoxanthin) and complex systems (microalgae extracts).

Bacterial species are able to colonize and establish communities in biotic and abiotic surfaces. Moreover, within the past five decades, incidence of bacterial strains resistant to currently used antibiotics has increased dramatically. This has led to diverse health issues and economical losses for different industries. Therefore, there is a latent need to develop new and more efficient antimicrobials. This work reports an increased production of an exopolysaccharide in a native yeast strain isolated from the Mexican Northeast, Rhodotorula mucilaginosa UANL-001L, when co-cultured with E. coli. The exopolysaccharide produced is chemically and physically characterized and its applications as an antimicrobial and antibiofilm are explored. The exopolysaccharide is capable of inhibiting planktonic growth and biofilm formation in Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Additionally, the exopolysaccharide studied here does not exhibit cytotoxic effects when assessed both, in vitro against an H9c2 mammalian cell line, and in vivo in a murine toxicity model. Taken together, the properties of this exopolysaccharide indicate that it has potential applications to inhibit bacterial colonization in medical and industrial settlings.Within the last five decades there has been an increased frequency in the emergence of bacterial strains resistant to commercially available antibiotics [1][2][3][4] . Therefore, there is an urgent need to seek, develop and design new antimicrobials to treat infections and to combat bacterial strains in industrial settings 5 . Bacteria have the ability to colonize biotic and abiotic environments through the formation of biofilms 6 . It has been estimated that 80% of bacterial infections in humans are caused by bacterial biofilms, and 50% of the nosocomial infections are

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BACKGROUND: A laboratory-scale protocol for the production, primary recovery and partial purification of fucoxanthin via biomass production at low light intensities was previously reported. This proposed approach exploited the use of ethanol salt aqueous two-phase systems (ATPS) and ultrafiltration (UF) to deliver a 45% total recovery yield if all steps were implemented in a bioprocess. In this study, practical experiences derived from the bench-scale implementation of the previously characterized lab protocol are presented. RESULTS:After implementation of the process, a 47.5% fucoxanthin recovery was obtained, while 87.2% of the contaminant proteins were removed. CONCLUSION: The findings reported here provide the required guidelines to facilitate process scale-up for the potential commercial production and recovery of fucoxanthin.