A peep into the transcriptome studies of the industrially important brown algae with special focus on Macrocystis genus / Una mirada a los estudios de transcriptoma en algas pardas de importancia industrial, en especial del género Macrocystis

Abstract 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.

Resumen Las algas pardas son una fuente comercial de diferentes polisacáridos / hidrocoloides utilizados para producir alimentos, productos farmacéuticos y otros productos biotecnológicos útiles. Por otra parte, la transcriptómica se ha convertido en una herramienta que no solo proporciona información valiosa para la comprensión de los procesos fisiológicos de una especie, sino que también permite la identificación de genes candidatos industrialmente importantes. Este estudio describe el transcriptoma de algas pardas y su aplicación industrial con un enfoque especial en Macrocystis integrifolia.

Using Macrocystis pyrifera (L.) C. Agardh from southern Chile as a source of applied biological compounds

The exploitation of seaweeds in Chile has been carried out for more than 60 years. More recently, seaweeds have been used for the production of alginate, agar and carrageenan, agricultural fertilizers and industrial aquaculture (feed for abalone and sea urchins), increasing the added value of this natural resource. In the Magellan Region (56ºS), the giant kelp Macrocystis pyrifera (L.) C. Agardh presents the most extensive kelp forest, reaching a biomass of approximately 12 kg.m-2. Recent studies have shown potential benefits from adding M. pyrifera- derived flour to salmonid feed. Research is currently underway to evaluate the useof brown algae-derived products for marine aquaculture feed of Oncorhynchus mykiss in tanks. There was no apparent adverse effect on the evaluated parameters that can be attributed to the incorporation of M. pyrifera meal in the diets fed to salmonids. Even when the control diet had numerically the best performance in zootechnical terms, the analysis of variance of all parameters evaluated showed no significant differences with regard to diets containing M. pyrifera meal. These results demonstrated that seaweed meal has important benefits for animal health and nutrition that could be applied or tested in other marine organisms of commercial importance.

The kelp macrocystis pyrifera as nutritional supplement for goats

The present study was aimed to evaluate Macrocystis pyrifera (MP) meal as a nutritional supplement for goats. There is an increasing interest to look at nutritional alternatives to guarantee a continuous supply of good quality forage for goats, in many communities around the world. Given its abundance and chemical composition, the algae M. pyrifera is an important potential resource as animal feed. Three diets with 10, 20, and 30% of MP meal concentrations and a control diet, with no algae, were evaluated. Four rumen cannulated goats, housed individually in metabolism cages, were used. The experimental design was a 4 x 4 Latin-Square. Feed and water intake, excreted urine and faeces, were measured. Digestibility in vivo, dry matter (DM) disappearance, and the metabolic variables of pH and ammoniacal nitrogen in the rumen, were determined. There was no significant difference in the feed intake but there was in water intake and urine excreted. No significant difference in digestibility in vivo among diets (P>0.05) was found. A significant difference (P<0.05) for degradability in situ was found for the algae diets containing 10 and 30 percent MP concentrations at 96 hours of sampling (78.3 and 82.2 percent). The raw algae in situ digestibility was 77 percent. A potential degradability of 87.3 percent was obtained with 30 percent MP diet. The highest effective degradation was obtained at an estimated rate of 0.02 h-1. Ruminal pH was higher (P<0.05) in all MP treatments (10 percent MP: 6.83, 20 percent MP: 6.85, 30 percent MP: 6.91). As suggested by the results, M. pyrifera represents a good unconventional feeding as a nutritional supplement for goats.

El objetivo de este trabajo fue evaluar Macrocystis pyrifera (MP) como suplemento alimenticio para cabras. Hay un interés creciente en buscar alternativas alimenticias para garantizar el suministro continuo de forraje de buena calidad para cabras en muchas comunidades del mundo. Dada su abundancia y composición química, el alga M. pyrifera es un recurso potencial importante como pienso para ganado. Se evaluaron tres dietas con concentraciones de 10, 20, y 30 por ciento de harina de MP, y una dieta control, sin las algas. Se utilizaron cuatro cabras canuladas dispuestas individualmente en jaulas metabólicas. El diseño experimental fue un Cuadrado Latino 4 x 4. El alimento y agua consumidos, la orina y las heces excretadas fueron medidas. Se determinaron la digestibilidad in vivo, la desaparición in situ de la materia seca y las variables metabólicas pH y nitrógeno amoniacal en rumen. No se encontró diferencia significativa en el alimento consumido, ni en la digestibilidad in vivo entre las dietas (P>0,05), pero si hubo diferencia significativa en el consumo de agua y la orina excretada (P<0,05). Se encontró diferencia significativa (P<0,05) para la digestibilidad in situ en las dietas que contenían el 10 y 30% del alga a la hora 96 del muestreo (78,3 y el 82,2 por ciento). La digestibilidad in situ del alga fue de 77 por ciento. Se obtuvo una degradabilidad potencial de 87,3 por ciento con la dieta que contiene 30 por ciento de MP. La mayor degradación efectiva se obtuvo a una tasa estimada de 0,02 h-1. El pH ruminal fue más alto (P<0,05) en todos los tratamientos con MP (10 por ciento de MP: 6,83, 20 por ciento de MP: 6,85, 30 por ciento de MP: 6,91). Los resultados obtenidos sugieren que M. pyrifera representa un buen suplemento nutricional no convencional para cabras.