Kinerja Pertumbuhan dan Kualitas Mikroalga Thalassiosira sp. yang dipelihara dengan Rasio Nitrogen:Silikon yang Berbeda

Abstract

The growth of Thalassiosira sp. is influenced by the availability of nitrogen (N) and silicon (Si), which play a role in the formation of cell components and frustule structure. A balanced N:Si ratio supports the growth and quality of microalgal cells. This study aimed to evaluate the effectiveness of different N:Si ratio formulations on the growth performance and quality of Thalassiosira sp. microalgae on a laboratory scale. The study used a completely randomized design (CRD) consisting of five treatments with four replicates, namely a ratio of N = 3.93 : Si = 3.93 (NSi1), a ratio of N = 3.93 : Si = 1.98 (NSi2), a ratio of N = 3.93 : Si = 1.31 (NSi3), and a ratio of N = 3.93 : Si = 0.92 (NSi4), as well as the standard hatchery formulation as a control (K), which has a ratio of N = 13.56 : Si = 2.53. The parameters observed were cell density, specific growth rate (SGR), cell quality, cell size, and culture water quality. The highest cell density and SGR of Thalassiosira sp. were obtained in the NSi1 and NSi2 treatments. A balanced N:Si ratio was able to increase cell density, specific growth rate, and cell quality.

Pertumbuhan Thalassiosira sp. dipengaruhi oleh ketersediaan nitrogen (N) dan silikon (Si) yang berperan dalam pembentukan komponen sel dan struktur frustul. Keseimbangan rasio N:Si mendukung pertumbuhan dan kualitas sel mikroalga. Penelitian ini bertujuan mengevaluasi efektivitas formulasi rasio N:Si terhadap kinerja pertumbuhan dan kualitas mikroalga Thalassiosira sp. pada skala laboratorium. Penelitian menggunakan Rancangan Acak Lengkap (RAL) yang terdiri atas lima perlakuan dengan empat ulangan, yaitu rasio N = 3,93 : Si = 3,93 (NSi1), rasio N = 3,93 : Si = 1,98 (NSi2), rasio N = 3,93 : Si = 1,31 (NSi3) dan rasio N = 3,93 : Si = 0,92 (NSi4) serta formula standar hatchery sebagai kontrol (K) yang memiliki rasio N = 13,56 : Si = 2,53. Parameter yang diamati yaitu kepadatan sel, laju pertumbuhan spesifik (LPS), kualitas sel, ukuran sel, dan kualitas air pemeliharaan. Kepadatan sel dan LPS Thalassiosira sp. tertinggi diperoleh pada perlakuan NSi1 dan NSi2. Rasio N:Si yang seimbang mampu meningkatkan kepadatan sel, laju pertumbuhan spesifik, dan kualitas sel.