Application of three microbiological preparations to control of water quality in industrialized shrimp culture

The experiment was conducted to determine the supplement of microbiological preparations Bacillus licheniformis (BL), Rhodopseudomonas capsulate (RC), Lactobacillus spp. (LB) on ammonia-N, nitrite-N, nitrate-N, chemical oxygen demand and active phosphate in industrialized shrimp culture. The experiments was composed of two teams and every team had two frequencies: control group, BL+RC added once per 7 days (G1), BL+RC added once per 3 days (G2), LB+BL added once per 7 days (G3) and LB+BL added once per 3 days (G4). The results showed that different microbiological preparations had different preponderance. At the aspect of reducing NH₄⁺, compared with control group, G1, G2 and G3 reduced 62%, 63% and 65%, respectively.In the first 21 days, G2 reduced 79% compared with control group. As for NO₂^-, compared with comparison, G1 reduced 46%. The best effect for controlling water quality was group G1. In addition, no groups resulted in significantly reduced PO₄^3-and COD. There is no striking difference between two frequencies in controlling the water quality. With the culture time increasing each index trended to increase.