%A NIM.: 21106030058 Nabila Novi Aryenny Putri %O Dr. rer. medic. Esti Wahyu Widowati, M. Si., M. Biotech. %T PENGARUH WAKTU FERMENTASI TERHADAP PRODUKSI PROTEIN SEL TUNGGAL DENGAN MEDIA LIMBAH CAIR TAHU %X Tofu liquid waste has high carbohydrate and protein content, so it can be used as a growth substrate for microorganisms to produce single cell protein (PST). The aim of this research was to determine the differences in PST production with varying fermentation times of 24, 48 and 72 hours from S. cerevisiae FNCC 3049 culture and P22a bacterial isolate and its application as additional protein in tilapia (Oreochromis niloticus) feed. The research results showed that the optimum growth time for S. cerevisiae FNCC 3049 in liquid tofu waste substrate was 48 hours with cell numbers and biomass of 1.93×109 CFU/ml and 0.02902 g/ml. Meanwhile, the optimum growth time for the Bacillus sp.P22a was 24 hours with a cell number and biomass of 4.78 × 1010 CFU/ml and 0.03129 g/ml. PST can be used as a nutritional supplement in fish feed. Pellets in this study resulted in an increase in absolute weight in tilapia with the addition of PST of F1 (1.2390 g), F2 (1.2501 g), F3 (1.3096 g), and F4 (1.4623 g) as well as feed conversion ratios (FCR) F1 (26.5114), F2 (26.4594), F3 (27.1019), and F4 (27.5249). These results meet the requirements according to SNI as fish feed because the protein content contained in the pellets exceeds 30%. Keywords: tofu wastewater, Saccharomyces cerevisiae, Bacillus sp.P22a, fermentation time, PST pellets %K tofu wastewater, Saccharomyces cerevisiae, Bacillus sp.P22a, fermentation time, PST pellets %D 2025 %I UIN SUNAN KALIJAGAYOGYAKARTA %L digilib70990