A peep into the transcriptome studies of the industrially important brown algae with special focus on Macrocystis genus

Brown algae are a commercial source of different polysaccharides/hydrocolloids that has been used to produce food, pharmaceutical, and several other useful biotechnological stuff. Nevertheless, transcriptomics has become a tool that not only provides valuable information for the understanding of the physiological processes of a species but also allows the identification of industrially important candidate genes. This study describes the transcriptome of brown algae and their industrial application with a special focus on Macrocystis integrifolia.

Effect of Seaweed Aqueous Extracts and Compost on Vegetative Growth, Yield, and Nutraceutical Quality of Cucumber (Cucumis sativus L.) Fruit

The objective of this research was to evaluate the production and phytochemical quality of cucumber (Cucumis sativus) fruits, in response to the foliar application of different seaweed extracts. This study was carried out under shadow mesh conditions in the autumn–winter agricultural cycle at the Instituto Tecnológico de Torreón, Torreón, Coahuila, Mexico. The experimental design was completely random, using six treatments with six repetitions each. The treatments evaluated were: Macrocystis pyrifera, Bryothamnion triquetrum, Ascophyllum nodosum, Grammatophora spp., Macrocystis integrifolia, and a control treatment with inorganic fertilization. The substrate used was a mixture of sand and vermicompost. The yield, commercial size, and phytochemical compounds of the fruit were evaluated. Results showed that the yield using Steiner solution (6.75 kg m−2) was higher than that obtained with Bryothamnion triquetrum algae (6.07 kg m−2). Regarding the phenolic content, the extracts surpassed the control treatment, with Macrocystis pyrifera and Macrocystis integrifolia being statistically equal, with values of 47.37 and 43.73 mg equiv. of Ac. Gallic 100 g fresh weight, respectively. The antioxidant capacity by ABTS+ and DPPH+ methods was higher using the treatment with Macrocystis pyrifera algae with 149.4 and 454.1 μM equiv Trolox/100 g fresh base, respectively. This treatment also presented the highest value of vitamin C with 5.07 mg/100 g fresh base, being 27% greater than the control treatment. Algae extracts increased the quality of the fruits by obtaining the highest antioxidant capacity, making their use a viable option to minimize the application of conventional fertilizers, thereby attenuating the effects on the environment and improving the health of the population.

EFECTO ANTIOXIDANTE Y ANTIFOTOENVEJECIMIENTO DE EXTRACTOS DE LA MACROALGA DEL LITORAL PERUANO DE Macrocystis integrifolia BORY Y ELABORACIÓN DE UNA FORMA DERMOCOSMÉTICA

El objetivo del estudio fue evaluar el efecto antioxidante y antifotoenvejecimiento de extractos de la alga parda Macrocystis integrifolia Bory y elaborar una forma dermocosmética. Obtenidos los extractos, se diseñó una forma dermocosmética en concentraciones de 1, 3 y 5%, elaboradas sobre una base de manteca de cerdo con incorporación de cera de abejas y aceite de sésamo a un pH de 6,5. La actividad antioxidante in vitro se determinó por lo métodos CDP y ABTS. La evaluación del efecto antifotoenvejecimiento in vivo se realizó empleando 25 ratones albinos hembra de la especie Mus musculus, cepa Bald/C53, que fueron distribuidos en cinco grupos de cinco ratones cada uno; a excepción del grupo que sirvió de blanco, el grupo control y los grupos de intervención fueron depilados en el lomo y se sometieron a la irradiación UVB durante 7 días, mañana y noche. El ensayo in vitro de la actividad antioxidante mostró que entre los extractos de estípite, fronda y bulbo de esta alga, existen diferencias en la capacidad antioxidante frente al radical libre ABTS, evidenciándose que el menor valor de IC50 (173,21 µg/mL) del extracto de fronda presenta mayor capacidad antioxidante total que el valor IC50 (3,23 µg/mL) de Trólox, sustancia de referencia. En el ensayo CDP se tuvo un valor de IC50 (669,7 µg/mL) por encima del estándar del ácido ascórbico IC50 (33 µg/mL). En el análisis antifotoenvejecimiento se observó, a niveles macro y microscópicos, notables diferencias favorables en los grupos de intervención. Se concluye que los extractos del alga parda estudiada tienen efecto antioxidante in vitro y antifotoenvejecimiento in vivo.

Biosorption of Mercury(II) with Different Marine Algae

Five species of algae (Lessonia nigrescens Bory, Prionitis decipiens, Grateloupia doryphora, Lessonia trabeculata and Macrocystis integrifolia) collected from Peruvian coast have been tested for mercury recovery from synthetic solutions. Preliminary experiments showed that optimum sorption occurred at pH 6-7 and that Lessonia algae were the most efficient sorbents for Hg(II). The biomass was cross-linked with calcium chloride. Stabilized biosorbent showed sorption capacity as high as 267 mg g-1 at pH 6. The sorption isotherm was described by the Langmuir equation, while the pseudo-second order equation was used for modeling uptake kinetics. Salt addition strongly affected mercury sorption following the sequence: NaNO3 << Na2SO4 <<< NaCl.