Lessonia berteroana en Perú: Comprobación de la identidad de la especie y diversidad genética en el borde norte de distribución

Harvest pressure on brown macroalgae of the Lessonia genus has increased in recent years in Peru and Chile, due to the high demand from the global hydrocolloid industry. After a taxonomic review, in 2012, the intertidal species Lessonia nigrescens was segregated into two species, being L. berteroana distributed in southern Peru and northern Chile (17-30°S). Based on genetic tools we confirm the identification as L. berteroana and report its presence up to 15°23’S. It is recommended to update the status of the species into Peruvian regulations and scientific publications.

The seaweed resources of Peru

The coast of Peru (3.5–18°S) is one of the most productive marine areas in the world. The updated seaweed checklist reports a total of 260 specific/intraspecific taxa, of which the Rhodophyta show the highest number (185 species), followed by Chlorophyta (41 species) and Phaeophyceae (34 species). Since 2012, an increase in molecular studies has been reported mostly in Rhodophyta, while Chlorophyta and Phaeophyceae have lagged far behind. Utilization of seaweed resources has been based on artisanal collection from natural beds. These are mainly consumed fresh or salt-dried (Chondracanthus chamissoi and Porphyra/Pyropia species), or exported for polysaccharide extraction (Lessonia nigrescens, Lessonia trabeculata, Macrocystis pyrifera). Although some regulations for brown seaweed extraction exist, overexploitation is a constant threat that must be addressed. Biomass from seaweed farms accounts, at most, for only 4% of the total annual landings, and there is a decreasing trend on seaweed aquaculture production since 2012. However, some cultivation projects for C. chamissoi and Porphyra/Pyropia species are currently being undertaken. In addition, recent studies have started to explore new uses of commercial and non-commercial seaweeds. Uncovering the Peruvian seaweed diversity and establishing well sustained culture and management projects are essential for utilizing and preserving the seaweed resources of Peru.

Actividad antibacteriana del extracto etanólico de Lessonia nigrescens Bory (Aracanto) frente a Staphylococcus aureus 6538 y Escherichia coli ATCC 8739

Se evaluó la actividad antibacteriana del extracto etanólico de la macroalga marina Lessonia nigrescens frente a cepas bacterianas tipificadas. La obtención del extracto se realizó a través de la técnica de maceración, para determinar la presencia de metabolitos se efectuó tamizaje fitoquímico, y la actividad antimicrobiana se evaluó por medio de técnica de difusión en agar Kirby Bauer. Los resultados evidenciaron que L. nigrescens frente a Staphylococcus aureus ATCC 6538 muestra un halo de inhibición promedio de 8.52mm y a Escherichia coli ATCC 8739 no muestra actividad; el tamizaje fitoquímico detectó la presencia de diversos compuestos, entre ellos fenólicos, esteroles, taninos y alcaloides. Concluyendo que el extracto etanólico de L. nigrescens Bory presentó actividad antimicrobiana únicamente frente a Staphylococcus aureusATCC 6538, atribuyendo dicha propiedad a los metabolitos encontrados.

Actividad antibacteriana del extracto etanólico de Lessonia nigrescens Bory (Aracanto) frente a Staphylococcus aureus 6538 y Escherichia coli ATCC 8739

Se evaluó la actividad antibacteriana del extracto etanólico de la macroalga marina Lessonia nigrescens frente a cepas bacterianas tipificadas. La obtención del extracto se realizó a través de la técnica de maceración, para determinar la presencia de metabolitos se efectuó tamizaje fitoquímico, y la actividad antimicrobiana se evaluó por medio de técnica de difusión en agar Kirby Bauer. Los resultados evidenciaron que L. nigrescens frente a Staphylococcus aureus ATCC 6538 muestra un halo de inhibición promedio de 8.52mm y a Escherichia coli ATCC 8739 no muestra actividad; el tamizaje fitoquímico detectó la presencia de diversos compuestos, entre ellos fenólicos, esteroles, taninos y alcaloides. Concluyendo que el extracto etanólico de L. nigrescens Bory presentó actividad antimicrobiana únicamente frente a Staphylococcus aureus ATCC 6538, atribuyendo dicha propiedad a los metabolitos encontrados.

Inhabiting fauna in holdfasts of Lessonia nigrescens complex. Is it an indicator of ecological integrity in exploited kelp beds in northern Chile?

Lessonia nigrescens complex holdfasts habitats are home to a wide diversity of invertebrates. The holdfasts associated fauna is sensitive to the kelp fishery in northern Chile because one of the management recommendation is to harvest the whole plant. Considering the above, and the ecological role play by brown algae as foundation species, this study proposes the use of fauna inhabiting the holdfasts as an ecological indicator to monitor the integrity of exploited kelp beds. To accomplish this objective, the morphology of plants and holdfasts was evaluated together with the composition, abundance and community structure associated in three types of resource conservation strategies based on fishery management spatially explicit: open access areas and management areas (to harvest), and marine protected areas (with no harvest), in Atacama and Coquimbo (26-32°S). The results show that high harvest pressure on exploited kelp beds transforms the plant morphology and holdfast, altering the colonization process and species aggregation predicted for these biogenic habitats modifying the expected biodiversity. Thus, associated fauna in open access areas has lower species richness, abundance and biodiversity of organisms than their counterparts in management areas or marine protected areas. Moreover, the structure of the holdfast associated communities, are more variables in open access areas. The results suggest that holdfasts are representative micro-ecosystems of the intertidal environment, and can be used as sampling replicable and comparable units to monitor exploited kelp beds integrity in fisheries open access areas. This ecological indicator is easy to evaluate and disseminate among users of the kelp productive chain.