Kappaphycus alvarezii (Rhodophyta, Areschougiaceae) cultivated in subtropical waters in Southern Brazil

Abstract

Four strains of Kappaphycus alvarezii were cultivated in the subtropical waters of Florianópolis, Santa Catarina State, Brazil (27°29′19′′ S/48°32′28′′ W), from February 2009 to February 2010. Seaweeds were cultivatedon floating raft near of mussel farms. Salinity ranged from 29 to 36 psu and temperature from 17.1 to 28.5°C. Higher growth rates (5.12-4.29% day −1 ) were measured in summer and autumn, showing a positive correlation between growth rate and water temperature. Lower growth rates (0.54-0.32% day −1 ) occurred in winter, resulted mainly by biomass loss. Significant differences were observed among the strains in spring and the brown tetrasporophytic strain was the only one which failed to recover, being excluded of the experiments. The effect of cultivation periods (36, 42, and 97 days) on carrageenan yield, gel strength, and viscosity were analyzed. Carrageenan yields were higher for plants kept 42 days in the sea (28%), against 25% for 36 and 97 days. There were no significant differences in carrageenan yield among the strains analyzed. Viscosity increased with the increase of cultivation period, while gel strength seemed to vary at random. Tetrasporangia and cystocarps were not observed, and lost fragments did not attach outside the raft. In general, dissolved inorganic nitrogen concentration decreased around the cultivation area as compared to the mussel farm. Results show that cultivation of K. alvarezii is technically feasible in subtropical waters and can be associated with local mussel farms, mitigating the eutrophication and, eventually, increasing the economic return of the farmers.

Algal polysaccharides as source of plant resistance inducers

“…Carrageenans are extracted from red algae (Rodophyta), mainly from Kappaphycus alvarezii (Doty) Doty ex Silva, grown in Philippines. The K. alvarezii was recently introduced in Brazil for rational cultivation (Hayashi et al, 2011). Before its introduction, there were attempts to Hypnea musciformis (Wulfen) Lamouroux cultivation, a naturally found species in the Brazilian coast, with little success (Hayashi et al, 2007).…”

Optimization of the extraction of carrageenan from Kappaphycus alvarezii using response surface methodology

“…Viscosity of carrageenan crude extract solutions (1.5% w/w) was measured using a Brookfield RVDV-III rheometer (Brookfield Engineering Laboratories, model DVIII Ultra, (HAYASHI et al, 2011). Hayashi et al (2011) showed that the cultivation of K. alvarezii can be technically feasible in subtropical water and can be associated with local mussel farms, mitigating eutrophication and, eventually, increasing the profitability of farmers.…”

“…Hayashi et al (2011) showed that the cultivation of K. alvarezii can be technically feasible in subtropical water and can be associated with local mussel farms, mitigating eutrophication and, eventually, increasing the profitability of farmers.…”

Cultivation of the red algae Kappaphycus alvarezii in Brazil and its pharmacological potential

“…In 2008, Hayashi et al (2011) analyzed the feasibility and the environmental risk of cultivating K. alvarezii in Santa Catarina state on the southern Brazilian coast. They concluded that the invasive risk is low and that, in the winter, the low water temperature is lethal to the species.…”