Growth Characteristics, Bio-chemical Composition and Antioxidant Activities of Benthic Diatom Grammatophora marina from Jeju Coast, Korea

Abstract

Benthic diatoms are known as a good food for shellfish in nature and in commercial hatchery of Jeju Island, Korea. Grammatophora marina is commonly found as dominant benthic micro-algae in Jeju coastal waters throughout the year. To know the best growth conditions of this species, culture was done in terms of three parameters; water temperature, salinity and nutrients. Each parameter was controlled by temperature of 15, 20 and 25°C; salinity of 25, 30 and 35 psu; and nutrient concentrations of 50, 100 and 200%. F/2 media was used with artificial seawater for the culture, which was continued for two weeks with L:D cycle 12:12 by using fluorescent light. Maximum specific growth rate was recorded 1.68 d-1 at temperature of 25°C with salinity of 35 psu and nutrient concentration of 200% on 6 th day during the culture period. Maximum biomass was also observed 4.9 × 10 5 cells mL-1 in the same condition. This species may belong to the euryhaline and eutrophic habitat with warm condition. For nutritional aspects of this species, protein, lipid and carbohydrate were measured. The value of protein, lipid and carbohydrate was 4.96%, 15.82% and 5.65%, respectively. The antioxidant activities of 80% methanolic extract were 46.7%, 23.7% and 23.8% on DPPH (1,1-Diphenyl-2-picrylydrazy) radical, superoxide anion radical and hydrogen peroxide scavenging, respectively. Percentage metal chelating activity was 81.2%. Enzymatic extracts of Alcalase and Ultraflow showed remarkable scavenging activities on DPPH radical (86.5% and 57.2%, respectively), and superoxide anion scavenging activities were 45.3% and 41.4% from Kojizyme and Viscozyme extracts, respectively. Extract of Protomex revealed 24.8% activity on hydrogen peroxide and Neutase showed 30.8% on hydroxyl radical scavenging effects. Celluclast and Viscozyme extracts showed 33.2% and 32.1% activities on nitric oxide scavenging, respectively, while Alcalase showed 61.5% on metal chelating. This species contains higher lipids among the biochemical compounds and higher metal chelating activities from both 80% methanolic and enzymatic extracts.

Effects of UV radiation on five marine microphytobenthic Wadden sea diatoms isolated from the Solthörn tidal flat (Lower Saxony, southern North Sea) – Part I: growth and antioxidative defence strategies

“…Similar observations have been reported by different authors (e.g. Nagayama et al, 2003;Affan et al, 2006;Goh et al, 2010) and are consistent with the fact that microalgae, and in particular diatoms, bear a number of antioxidant compounds, including carotenoids, polyunsaturated fatty acids and polysaccharides (Mohamed, 2008;Holtin et al, 2009;Scholz et al, 2014). In contrast, both the long-term UV-B-and combined UV-treatments of the five diatom taxa showed significant correlations between the DPPH and FRAP assays and the total phenolic contents (P < 0.05), suggesting that phenolic compounds could be involved in acclimatization to at least UV-B long-term exposure.…”

“…(e.g. Affan et al, 2006;Goh et al, 2010). According to Hanaa et al (2008) these compounds are extracted by dichloromethane and might contribute to the high scavenging activities found in the present study.…”

“…For example, using the commercial antioxidant α-tocopherol as equivalent in the present study for the long-term UV-B exposure, the antioxidant activities of the pooled extract of Achnanthes exigua would be 83.5%, 36.4%, 41.5% and 67.1% on DPPH radical, superoxide anion scavenging, hydrogen peroxide scavenging and hydroxyl radical, respectively. In contrast, Affan et al (2006) found up to 36.8% lower values in the scavenging activities for 80% methanolic extracts of the benthic diatom Grammatophora marina. Such differences might have arisen from using only one solvent extract but can also be species specific.…”

Factors governing phytoplankton biomass and production in tropical estuaries of western Taiwan

“…The saturation irradiance for benthic microalgae was low, ranging from 66 to 185 μmol photons m À 1 s À 1 (Guarini et al, 2002;Serôdio et al, 2012). The growth condition was still good for Grammatophora marina when cultured under 180 μmol photons m À 1 s À 1 (Affan et al, 2006). In this study, the P-E curves showed that the E k for phytoplankton at Dm in fall 2013 was 157 μmol photons m À 1 s À 1 .…”

GROWTH CHARACTERISTICS AND ANTIOXIDANT PROPERTIES OF THE BENTHIC DIATOM NAVICULA INCERTA (BACILLARIOPHYCEAE) FROM JEJU ISLAND, KOREA1

“…Isolation of Navicula incerta. The isolation procedure was performed as described in Affan et al. (2006).…”