Lee, J; Affan, A; Kim, B; Jeon, Y; Karawita, R
American Geophysical Union, 2000 Florida Ave., N.W. Washington DC 20009 USA, [URL:http://www.agu.org/pubs/agu_joureos.html]
Benthic diatoms are known as a good food for shellfish aquaculture. Navicula genus is one of abundant benthic diatoms found in Jeju coast throughout the year. We isolated Navicula mono-strain by axenic culture in order to survey growth characteristics, biochemical compositions and some activity tests. To know the best growth conditions, culture was done in terms of three parameters such as water temperature, salinity and nutrients. Each parameter was controlled by 15 degree C, 20 degree C and 25 degree C of temperature, 25 psu, 30 psu and 35 psu of salinity, and 50%, 100% and 200% of nutrient concentration. For nutrient source, F/2 media was used with artificial seawater. A growth experiment was continued for two weeks with LD cycle 12:12 using fluorescent light. A maximum growth rate was recorded 1.68 day super(-1) at 20 degree C, 30 psu and 100% nutrients on 12th day during culture period. A maximum biomass was also observed 7.99 x 10 super(5) cells ml super(-1) on the same condition. For nutritional aspects of this species, protein, lipid and carbohydrate were measured. The composition percentage of protein, lipid and carbohydrate was 4.16%, 14.12% and 4.85% per one-gram dry weight, respectively. Antioxidant activities of 80% methanol extract on DPPH (1,1-Diphenyl-2-picrylydrazy) radical, super-oxide anion radical, hydrogen peroxide scavenging and nitric oxide scavenging were 62.8%, 27.6%, 16.8% and 9.2%, respectively. Metal chelating activity was 68.5%. This species represents high values in lipid composition and chelating activity.
Diatoms; Nutrient concentrations; Lipid composition; Phytoplankton; Biomass; Metals; Marine environment; Growth; Hydrogen peroxide; Anions; Salinity; Nutritional requirements; Temperature; Nutrient sources; Salinity effects; Carbohydrates; Coasts; Methanol; Lipids; Shellfish culture; Antioxidants; Growth rate; Axenic culture; Growth conditions; Food; Oceans; Navicula; Radicals; Pure culture; Bacillariophyceae; Nitric oxide; Marine; Water temperature; Protein composition; Marine aquaculture; Temperature effects; Nutrients; Proteins; Cell culture; Biochemical composition; Aquaculture; Media (culture); Light effects