Peran Bakteri Pelarut Fosfat dan Actinomycetes terhadap Kualitas Air dan Dinamika Fitoplankton pada Budidaya Udang Vaname Litopenaeus vannamei

Abstract

DIAZ DAFARA PUTRA. Peran Bakteri Pelarut Fosfat dan Actinomycetes terhadap Kualitas Air dan Dinamika Fitoplankton pada Budidaya Udang Vaname Litopenaeus vannamei. Dibimbing oleh YUNI PUJI HASTUTI dan KUKUH NIRMALA. Budidaya udang vaname secara intensif menghasilkan akumulasi bahan organik dan nutrien yang dapat menurunkan kualitas air media pemeliharaan. Penelitian ini bertujuan mengevaluasi pengaruh penambahan bakteri pelarut fosfat (BPF) dengan kepadatan berbeda dan Actinomycetes terhadap kualitas air, dinamika fitoplankton, pertumbuhan, dan kelangsungan hidup udang vaname. Penelitian menggunakan rancangan acak lengkap (RAL) dengan empat perlakuan, yaitu kontrol tanpa penambahan bakteri (K), penambahan BPF 10², 104, dan 106 CFU mL?¹ yang dikombinasikan dengan Actinomycetes 10² CFU mL?¹, masing-masing dengan tiga ulangan selama 28 hari pemeliharaan. Parameter yang diamati meliputi kualitas air, kelimpahan dan indeks fitoplankton, rasio konversi pakan (RKP), laju pertumbuhan spesifik (LPS), serta tingkat kelangsungan hidup (TKH). Hasil penelitian menunjukkan bahwa penambahan BPF dan Actinomycetes mampu memperbaiki kondisi media budidaya melalui penurunan bahan organik serta memengaruhi dinamika senyawa fosfor dan kelimpahan fitoplankton. Penambahan kedua bakteri tidak memberikan pengaruh nyata terhadap RKP dan LPS, tetapi memberikan pengaruh nyata terhadap TKH. Perlakuan BPF 102 + Actinomycetes 102 menghasilkan kelimpahan fitoplankton dan tingkat kelangsungan hidup tertinggi sehingga menjadi perlakuan terbaik pada penelitian ini.

Kata kunci: actinomycetes, bakteri pelarut fosfat, fitoplankton, kualitas air, Litopenaeus vannamei.

DIAZ DAFARA PUTRA. The Role of Phosphate-Solubilizing Bacteria and Actinomycetes on Water Quality and Phytoplankton Dynamics in Pacific White Shrimp Litopenaeus vannamei Culture. Supervised by YUNI PUJI HASTUTI dan KUKUH NIRMALA Intensive culture of Pacific white shrimp (Litopenaeus vannamei) is often associated with the accumulation of organic matter and nutrients, leading to the deterioration of water quality. This study aimed to evaluate the effects of phosphate-solubilizing bacteria (PSB) combined with Actinomycetes on water quality, phytoplankton dynamics, growth performance, and survival of Pacific white shrimp. A completely randomized design consisting of four treatments with three replicates was conducted over a 28-day culture period. The treatments consisted of a control without bacterial supplementation and three combinations of PSB at densities of 10², 104, and 106 CFU mL?¹ with Actinomycetes at 10² CFU mL?¹. The observed parameters included water quality, phytoplankton abundance and community indices, feed conversion ratio (FCR), specific growth rate (SGR), and survival rate (SR). The results demonstrated that the combined application of PSB and Actinomycetes improved the culture water quality by reducing organic matter accumulation, influencing phosphorus dynamics, and increasing phytoplankton abundance. However, bacterial supplementation had no significant effect on FCR and SGR but significantly improved shrimp survival. Among all treatments, PSB 102 + Actinomycetes 102 produced the highest phytoplankton abundance and survival rate, indicating that it was the most effective treatment under the culture conditions of this study.

Keywords: actinomycetes, phosphate-solubilizing bacteria, phytoplankton, water quality, pacific white shrimp.