THE EFFECT OF N/P RATIO OF UREA AND TSP FERTILIZERS IN WALNE MEDIA ON THE GROWTH PATTERN OF AND PROTEIN CONTENT OF Thalassiosira Sp. DIATOM CELLS

The availability of natural feed needed in hatchery business is very significant due to the fact that natural feed will help the hatchery process to produce good and hi-quality seeds. Thalassiosira sp. is a type of diatom phytoplankton widely used to feed shrimp larvae. Walne media is a medium commonly used in the process of phytoplankton culture. Nutrient has considerable effect on the biochemical composition of phytoplankton, such as the content of protein, amino acids, carbohydrates, fats, and fatty acids. Nitrates and phosphorus contained in water are the main nutrients for phytoplankton to produce chlorophyll. One of the fertilizers which can be used for phytoplankton culture is agricultural fertilizers such as urea and TSP. The aims of this study were (1) to examine the effect of the application of the N/P ratio of urea and TSP in Walne media on the growth pattern and protein content of Thalassiosira sp. diatom cells; and (2) to determine the best value of the N/P ratio of urea and TSP fertilizers in Walne media which provides growth patterns and protein content of diatom cells of Thalassiosira sp. The method used in this research was an experimental method. The experimental method used was a completely randomized design (CRD) with 5 treatments and 4 designs, each treatment was as follows: applying different N/P ratios of urea and TSP fertilizers in Walne media, i.e. (A) 1:1; (B) 4:1; (C) 8:1; (D) 12:1; and (E) 16:1. The results of this study showed that algae growth increased from 0:0 to 16:0 N:P ratio. The growth of diatoms with the highest density occurred in treatments A and B with cell densities of 2.255×106 to 2.256×106 cells/ml compared to the other N:P ratios. It can be concluded the 1:1 N/P ratio of urea and TSP fertilizers in Walne media had a significant effect on growth patterns and protein content of diatom cells of Thalassiosira sp.