In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in degrading organic pollutants at the bottom of shrimp ponds, were studied. The results showed that the favorable fermentation medium （per L） was 25 g of peptone, 5 g of yeast extract, and 0.2 g of ferric phosphate, and the initial pH value of the medium was 8.0. The optimum fermentation time was 20 h. The optimum stirring way was stirring one hour after one hour. Iso-electric point sedimentation collecting method was the most efficient and economic method to collect the bacteria cells after fermentation, with the optimum sediment pH of 3.67, 4.02, and 3.40 for the strains Lt7222, Gy7018 and Lt7511,respectively. It was also indicated that the survival and reproducing ability of the bacterial cells were not affected by the sedimentation process.
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.
