ABSTRACT
Marine biofouling occurs when microorganisms, plants, algae, or animals gather on any surface of a man-made object or natural structure. Biofouling organisms are important components of marine ecosystems and vary seasonally and regionally, with environmental factors such as temperature, amount of light, and nutrient availability. Since marine organisms have unique growth patterns, they can be used in marine forensic investigations to estimate time and environment. As few such studies have been done, this study analyzed the growth rates of Balanus on 100 × 100 mm panels of PVC, stainless steel, wood, and cloth and compared these with environmental factors such as temperature. Sets of panels were immersed in Sokcho Harbor, South Korea, each month, and observed monthly after immersion using American Society for Testing and Materials methods. The Balanus on the test panels grew to 1-20 mm and showed different growth patterns depending on when the panels were first immersed.
Subject(s)
Biofouling , Thoracica , Animals , Ecosystem , Republic of KoreaABSTRACT
The microalga Haematococcus lacustris has a complex life cycle and a slow growth rate, hampering its mass cultivation. Culture of microalgae with organic carbon sources can increase the growth rate. Few studies have evaluated the effects of organic carbon sources on H. lacustris. We compared the vegetative and inductive stages of H. lacustris under autotrophic and mixotrophic conditions using four organic carbon sources: sodium acetate, glycerol, sodium gluconate, and ribose, each at various concentrations (0.325, 0.65, 1.3, and 2.6 g/L). The cell density was increased by 1.3 g/L of glycerol in the vegetative stage. The rapid transition to the inductive stage under nitrogen-depletion conditions caused by 1.3 or 2.6 g/L sodium acetate promoted the accumulation of astaxanthin. The production of astaxanthin by H. lacustris in mass culture using organic carbon sources could increase profitability.
