Seto Windarto, Diana Rachmawati, Rosa Amalia, Diwyacitta Antya Putri
Organic fertilizers such as vermicompost represent sustainable biofertilizers that can enhance biomass yield, biochemical quality, and bioactivity of high-value crops, including seaweeds. This study assessed the effects of vermicompost supplementation on the edible seaweed Caulerpa racemosa during 45 days of cultivation using five treatments: V0 (control, no vermicompost), V1 (125 g/m3), V2 (250 g/m3), V3 (375 g/m3), and V4 (500 g/m3). Parameters evaluated included growth performance, proximate composition, photosynthetic pigments, total phenolic content (TPC), antioxidant activity (DPPH and ABTS assays with IC50 determination), nutrient use efficiency (NUE), sensory quality, and water quality. Moderate vermicompost application (V3) produced the highest biomass (147.67 ± 15.91 g) and specific growth rate (2.97 ± 0.21 %/day), while excessive supplementation (V4) limited growth. Fertilized treatments improved nutritional quality, with increases in protein (13.55 ± 0.45%), ash (47.41 ± 0.18%), and lipid content (1.22 ± 0.11%), alongside elevated chlorophyll (1547.97 ± 0.89 μg/g), carotenoid (308.81 ± 0.65 μg/g), and TPC (12.50 ± 0.04 mg GAE/g) levels. Antioxidant activity was significantly enhanced, with the lowest IC50 values of 272.80 ± 1.17 ppm (DPPH) and 190.76 ± 3.47 ppm (ABTS). Sensory evaluation showed superior taste, color, crispiness, and overall acceptance in V4, while NUE was highest in V3 (92.2%). Water quality parameters remained within optimal ranges for seaweed cultivation. The improvement of growth, nutrient composition, and antioxidant activity in C. racemosa through vermicompost supplementation highlights its promise as a bio-based input for advancing seaweed biotechnology and eco-friendly agricultural practices. © 2026 Elsevier Ltd
Department of Aquaculture, Faculty of Fisheries and Marine Science, Universitas Diponegoro, Semarang, 50275, Indonesia; Department of Food Technology and Agricultural Product, Faculty of Food Security, Universitas Negeri Surabaya, Surabaya, 60231, Indonesia
