Abstract:
The experiment was conducted to determine the effect of the supplement of probiotics (Bacillus sp., photosynthetic bacteria, and Bacillus sp.+photosynthetic bacteria) on pH, H2S, chemical oxygen demand, ammonia-N, nitrate-N and survival rate in breeding of Litopenaeus vannamei. The results showed that photosynthetic bacteria had some effect on preventing low pH occur but Bacillus sp. did not show similar function; the concentration of H2S, ammonia-N, or nitrate-N was significantly decreased by the supplement of probiotics. Photosynthetic bacteria eliminated H2S and nitrate more strongly while Bacillus sp. eliminated ammonia-N more effectively. However, the use of probiotics had no obvious effect on COD, which concentrations were harmless to larvae in this experiment. The survival rate of larvae was significantly increased by the supplement of 5 mgL-1 of Bacillus sp. and 1 mgL-1 of Bacillus sp. together with 10 mgL-1 of photosynthetic bacteria. Considering the integrated effect on water quality and survival rate, we conclude that the optimum treatment was 1 mgL-1 of Bacillus sp. together with 10 mgL-1 of photosynthetic bacteria in this experiment. It seems that the effect can be enhanced by using Bacillus sp. and photosynthetic bacteria together.