Evaluation of NPK, Nitrogen (N)-Phosphorus (P)-Potassium (K), fertilizer to escalate Tetraselmis sp. production

Abstract Culture of Tetraselmis sp. requires Conway medium fertilizer with a complete and appropriate composition to support its growth. However, Conway fertilizer is quite expensive to be afford by farmer. One alternative fertilizer that can be used is commercial NPK fertilizer which is relatively cheap and easy to be obtained. NPK fertilizer contains nitrogen, phosphate, and potassium which are useful for the growth of plankton, including Tetraselmis sp. This research aimed to evaluate the production performance of Tetraselmis sp. using NPK fertilizer at semi-scale mass level. This study used a completely randomized design with three replications and three experiments (A = Conway as control, B = commercial NPK fertilizer with a ratio of N 16%, P 16%, K 16%, and C = commercial NPK fertilizer with an N content ratio of 6 %, P 20%, K 30%). The parameters of this study were population density, cell size, and nutritional content of Tetraselmis sp. The results showed that the peak population density and cell diameter did not differ in each treatment, although treatment C had the highest density (3.63±1.22 × 10 6 cells/ml). Protein content had values that were not significantly different (21.93–23.16%). The highest fat value was owned by treatment (6.8%). The research results showed that the use of NPK fertilizer in semi-scale mass cultures of Tetraselmis sp produced density, cell size and nutritional protein content that were not significantly different from Conway fertilizer. It is indicated that NPK fertilizer could be used as media of Tetraselmis sp. due to its cheap price and same performance.