On the basis of purifying effect of single-strain probiotic bacteria on water of intensive turbot breeding,the purifying effect of multi-strain bacteria product was studied.The results of experiments showed that the free multi-strain mixed bacteria had better purifying effect on turbot breeding water than that of any single-strain bacteria.this phenomenon can be explained with the principle of " bio-pump".The immobilized multi-strain probiotics product,bio-film,also showed excellent purifying effect on water of turbot breeding.The removal rates of COD and ammonia in 5 days were up to 73.1% and 80.0%,respectively.The concentration of nitrite kept low,which indicated most ammonia had been transformed into nitrate and accumulation of harmful intermediate product-nitrite was decreased.This paper supplied theoretical and technical foundation for saving sea water through bio-purification of wastewater from marine fish culture.
