#TITLE_ALTERNATIVE#

• Main Author: (NIM : 10414031), IRWAN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28144
• Institution: Institut Teknologi Bandung

<p align="justify"> <br /> <br /> White shrimp (Litopenaeus vannamei) is an aquaculture commodity of Indonesia with 410.000 tons production in 2015. However, there were still a common problem in the cultivation of white shrimp, which is vulnerability to infection of pathogenic Vibrio sp., lead to mass death. One potential strategy for handling the problem is biofloc technology. Biofloc is a collection of microorganisms, that live in aggregate. Biofloc can be formed internally in ponds, but the production is difficult to control. Therefore, this research studied external biofloc production using microbial cultures: (1) Bacillus cereus, (2) B. megaterium, (3) Chaetoceros calcitrans microalgae, and (4) nitrifying bacteria consortium Nitrosomonas sp. and Nitrobacter sp., on the three variations in inoculum percentage ratio 1: 1: 6: 6, 1: 1: 5: 7 and 1: 1: 7: 5 (% v/v). 0.5% molasses substrate (v/v) as carbon source and ZA fertilizer as a nitrogen source with a C: N = 15: 1 ratio in 5 ppt salinity seawater. Physical and chemical conditions, dry weight, and size of biofloc particles were observed at the 2nd, 4th, 6th and 8th day of production. The optimum yield was achieved with a culture ratio of 1: 1: 6: 6 within 6 days period, with an average floc size of 109.3±3 &#956;m and volume index of 76.67±5.77 mL/L. Optimal biofloc achieved is then applied to the challenge test for 3 days. There were six treatments of abstinence test: (NET) neutral control, without addition of biofloc or Vibrio sp., (P) positive control, with the addition of biofloc only, (N) negative control, with addition of Vibrio sp. (1) the addition of biofloc 24 hours before, (2) simultaneously with, and (3) 24 hours after the addition of Vibrio sp. During the challenge test, it was observed the shrimp survivals, water condition, and the dynamics of microbial populations on water and shrimp. The results of the shrimp life of each treatment reached (NET) 68.6±2.31%, (P) 71.2±0.92% (N) .67±2.53%, (1)58.67±2.66%, (2) 59.6±3%, dan (3) 55.33±2.21% after three days of treatment. There were 11 dominant bacteria isolates during the challenge test process from water insulation and culture shrimp. In general, it can be concluded that the administration of biofloc can increase the life of the white shrimp post-larvae culture to the exposure of Vibrio sp. <p align="justify"> <br />