Purification Of Aquaculture Water With Rhodobacter Sphaeroides And Bacillus Subtilis

In recent years, as people’s living standards improve, aquaculture in China has rapiddevelopment, while the farming intensification improved constantly with the expansion of thefarming scale, and bait and excretion are accumulated continuously in the water ofaquaculture, causing increasingly serious pollution in aquaculture, which leadto the disease occurred frequently in aquaculture and endanger the culture organisms directly.Therefore, how to improve the aquaculture water quality become the key issues for thesuccess or failure of aquaculture, and the use of beneficial micro-organisms to improve themicro-ecological environment and water quality of the aquaculture water become a hottopic in current research. There are four aspects followed in the paper:1The identification of photosynthetic bacteria. In this paper, one photosynthetic bacteriaisolated from the sediment of Baiyangdian is identified as Rhodobacter sphaeroides, based onthe results of morphological, physiological and biochemical characteristics and thehomological analysis of16S rDNA sequence.2The purification of aquaculture water with photosynthetic bacteria and Bacillus subtilis.Photosynthetic bacteria, isolated before, and B.subtilis, stored in lab, are studied about theirpurification capacity to aquaculture water. The results showed that, the optimumconcentration of photosynthetic bacteria for purification is8×10~4cfu/ml, and the optimumconcentration of B.subtilis is18×10~4cfu/ml, according to the comprehensive analysis ofwater purification effect and the cost. To find the synergy ratio of R.sphaeroides and B.subtilis,experiments about water purification with five kinds of ratio combination of bacteria (3:1,2:1,1:1,1:2,1:3) were studied, which results showed that the best ratio of R.sphaeroides andB.subtilis is1:1that ammonia and nitrite reduced72%and82.5%respectively.3The purification of aquaculture water of Trionyx sinensis with R.sphaeroides andB.subtilis. The results of experiments showed that, the purification effect in the aquaculturewater in which there are mixed bacteria is better than that in the aquaculture water in whichthere is only one bacteria, and the ammonia,the nitrite and the COD are reduced42.9%,60.8%and31.1%after8days, respectively.4The purification of aquaculture water of Neocaridina denticulate sinensis withR.sphaeroides and B.subtilis. The purification study showed similar results that the ammonia,the nitrite and the COD in the aquaculture water in which there are mixed bacteria is lower obviously than that in the aquaculture water in which there is only one bacteria. After45days,the ammonia, the nitrite and the COD in the water in which there are mixed bacteria arereduced74.3%,70.6%, and56.9%, respectively.