Effects of Ultraviolet Radiation (UV‐A+UV‐B) on the Antioxidant Metabolism of the Red Macroalga Species Acanthophora spicifera (Rhodophyta, Ceramiales) From Different Salinity and Nutrient Conditions

Abstract

Acanthophora spicifera (M.Vahl) Børgesen is a macroalga of great economic importance. This study evaluated the antioxidant responses of two algal populations of A. spicifera adapted to different abiotic conditions when exposed to ultraviolet-A+ultraviolet-B radiation (UV-A+UV-B). Experiments were performed using the water at two collection points for 7 days of acclimatization and 7 days of exposure to UVR (3 h per day), followed by metabolic analyses. At point 1, water of 30 AE 1 practical salinity unit (psu) had concentrations of 1.06 AE 0.27 mM NH þ 4 , 8.47 AE 0.01 mM NO À 3 , 0.17 AE 0.01 mM PO À3 4 and pH 7.88. At point 2, water of 35 AE 1 psu had concentrations of 1.13 AE 0.05 mM NH þ 4 , 3.73 AE 0.01 mM NO À 3 , 0.52 AE 0.01 mM PO À3 4and pH 8.55. Chlorophyll a, phycobiliproteins, carotenoids, mycosporins, polyphenolics and antioxidant enzymes (catalase, superoxide dismutase and guaiacol peroxidase) were evaluated. The present study demonstrates that ultraviolet radiation triggers antioxidant activity in the A. spicifera. However, such activation resulted in greater responses in samples of the point 1, with lower salinity and highest concentration of nutrients.

Effects of seawater acidification and solar ultraviolet radiation on photosynthetic performances and biochemical compositions of Rhodosorus sp. SCSIO-45730

“…Additionally, UVR increased the activities of SOD and CAT, thereby regulating homeostatic balance in algal cells against UVinduced oxidative damage. UVR also induced the production of antioxidants, such as phenolic compounds, which helped to counteract the detrimental effects of UVR, and such phenomena were also observed in Ulva rigida (Cabello-Pasini et al, 2011) and Acanthophora spicifera (Pereira et al, 2019).…”

Valorization of the chemical diversity of the tropical red seaweeds Acanthophora and Kappaphycus and their applications in aquaculture: A review

“…Concentrations of 0.79-2.39 mg/g dry weight of lutein, 5.79-11.28 mg/g dry weight of zeaxanthin, 1.59-16.16 mg/g dry weight of a-carotene were reported (Pereira et al, 2019), while antheraxanthin, b-cryptoxanthin and b-carotene were identified in A. spicifera based on their retention time and comparison with standards (Aihara and Yamamoto, 1968). Also, the concentration of 0.02 mg/g dry weight of b-carotene, 0.02 mg/ g dry weight of zeaxanthin, and 0.02 mg/g dry weight of lutein were reported for A. nayadiformis (Petrocelli and Felicini, 1995).…”

“…is rather limited. A. spicifera contained 0.34 mg of R-PC, 0.121 mg of R-APC and 1.061 mg of R-PE per gram fresh weight (Senthilkumar et al, 2013;Pereira et al, 2019) while A. nayadiformis contained 0.20-0.28 mg/g dry weight of Chl a, 2.20-5.54 mg/g dry weight of R-PE and 1.68-3.91 mg/g dry weight of R-PC (Petrocelli and Felicini, 1995) (Table 5).…”