Effects of nitrate and phosphate availabilities on growth, photosynthesis and pigment and protein contents in colour strains of Hypnea musciformis (Wulfen in Jacqu.) J.V. Lamour. (Gigartinales, Rhodophyta)

Abstract

Abstract:In Brazil, Hypnea musciformis is the main raw material for carrageenan production and the knowledge of nitrogen and phosphorus metabolism in algae is critical for the success of cultivation because these elements can limit seaweed productivity. Thus, the objective of this study was to evaluate the effects of nitrate (zero to 100 µM) and nitrate plus phosphate (zero to 25 µM) availabilities on the growth, the contents of photosynthetic pigments (phycobiliproteins and chlorophyll a) and proteins, and the photosynthesis and respiration of the brown (BR) and light green (LG) strains of H. musciformis. The results revealed metabolic differences between the colour strains of H. musciformis for nitrogen metabolism: upon nitrate addition, the LG strain stored nitrogen mainly as proteins, while the BR strain stored it as proteins and pigments. Moreover, the respiration of the LG strain and the photosynthesis of the BR strain increased with nitrate concentrations, indicating that the BR strain fixed more photosynthetic carbon than the LG strain. Keywords:colour strain Hypnea nitrate phosphate photosynthesis IntroductionThe genus Hypnea (Gigartinales, Rhodophyta) includes about fi fty species that are distributed in warm water areas (Masuda et al., 1997), of which six species are known in Brazil (Schenkman, 1986;Nunes, 2005). Hypnea musciformis (Wulfen in Jacqu.) J. V. Lamour. is a species with wide geographical distribution along the Brazilian coast and is the main raw material for carrageenan production (Oliveira, 1998). Carrageenan is a sulfated polysaccharide widely used in the food and pharmaceutical industries; it also has antiviral activity, inhibiting, for example, HSV and HIV (Neushul, 1990).The concern with the impoverishment of natural beds of H. musciformis led to several investigations, which found that there are large variations in biomass and carrageenan yields during the year related to seasonality (Schenkman, 1989;Faccini & Berchez, 2000;Ramos et al., 2006). Since the carrageenan production from natural populations is very variable, studies were undertaken to determine the best conditions for H. musciformis cultivation in the laboratory, and in the ocean (Faccini & Berchez, 2000; Reis et al., 2003; Schenkman, 1989). However, few studies evaluated the nutrient requirements of this species.Nitrogen is considered to be the primary limiting nutrient for algal growth in marine ecosystems. Thus, the success of seaweed cultivation requires a knowledge of the nitrogen requirements of the algae (Hanisak, 1990). In the absence of this nutrient, many algae present the following changes: hair formation (DeBoer & Whoriskey, 1983;O'Connor & West, 1991); a decrease in growth (Hwang et al., 1987;Collén et al., 2004); a decrease in the contents of soluble proteins and phycobiliproteins (Collén et al., 2004); a decrease in the nitrate, nitrite and aminoacid contents of the thallus (Hwang et al., 1987); a decrease in photosynthesis and in the activities of enzymes involved in carbon metabolism (Collén et al., 2004) ...

Seasonal fluctuation of photosynthetic pigments of most common red seaweeds species collected from Abu Qir, Alexandria, Egypt

“…Chlorophyll a of Hypnea cervicornis (red algae) was stimulated by high phosphate (Bird et al 1982). Lapointe (1986) detected that phosphorus enrichment can stimulate the growth and the photosynthetic rates of some algae, and Martins et al (2011) found that there is a positive correlation between the increase of phosphate in the medium and the content of Hypnea musciformis photosynthetic pigments.…”

Growth and biochemical characterization of green and red strains of the tropical agarophytes Gracilaria debilis and Gracilaria edulis (Gracilariaceae, Rhodophyta)

“…The reason may be intra-species and inter-species variation in the response to physicochemical parameters of the seawater. Martins et al (2011) stated that metabolic differences found between the color strains of Hypnea musciformis when cultures with nitrate addition. The light green strain of H. musciformis stored nitrogen mainly as proteins, while the brown strain stored it as proteins and pigments and it fixed more photosynthetic carbon than the light green strain.…”

Potential Area Mapping for Seaweed Aquaculture Based on Interval Type-2 Fuzzy Sets and Multi-Layer Perceptron Algorithm.

“…The speed of seawater that is good for the growth of seaweed is in the range of 20-40 cm / s Nursidi et al (2017) stated that, an increase in nitrate would increase the growth of seaweed. An increase in the availability of nitrate sources is a sign that there is an increase in the amount of protein contained (Martins et al 2011). Nitrogen is considered as the main nutrient for the growth of seaweed in the ecosystem maritime (Hanisak 1990).…”