The Study Of The Composition Of Culturable Bacteria And Phosphorus Removal Bacteria Screening And Performance In Circulating Water Aquaculture System

Study on construction of cultured bacteria and screen,nature of phosphorus-accumulating bacteria Unlike denitrification of nitrogen can get nitrogen,phosphorus can not be removed as simple substance.An excess of phosphorus lead to eutrophication,phytoplankton absorb inorganic phosphorus in water and proliferation,leading to water bloom or red tide,do harm to aquatic biological.The traditional method of inhibiting bacteria and blue-green algae is put antibiotics and heavy metal chelates,at the same time,it also do harm to aquatic food safety.At present,biological phosphorus removal is an effective and economical method of phosphorus removal.In order to explore composition of cultured bacteria and isolation a better phosphorus removal phosphorus-accumulating bacteria in intensive recirculating aquaculture systems.In this paper bacteria is from biological aerated filter of 4 different intensive recirculating aquaculture systems of Cynoglossus semilaevis and Epinephelus malabaricus,Takifugu rubripes and Scop Hthalmus maximus,used agar culture bacteria,isolated and purified bacteria by streak plate method.Isolated 4 groups of bacteria in Epinep Helus malabaricus intensive recirculating aquaculture system,2 groups of bacteria in Cynoglossus semilaevis intensive recirculating aquaculture system,5 groups of bacteria in Scop Hthalmus maximus intensive recirculating aquaculture system,5 groups of bacteria in Takifugu rubripes intensive recirculating aquaculture system,total 16 groups of cultured bacteria.Composition and concentration of bacteria varied in 4 different intensive recirculating aquaculture systems,it probably relate to hydration environment and intestinal flora.Determined phosphorus removal capacity of isolated cultured bacteria,all beceria have capacity of removal phosphorus(>13.4%),expect for WC in in Epinep Helus malabaricus intensive recirculating aquaculture system and DO in Scop Hthalmus maximus intensive recirculating aquaculture system(<4%).In each intensive recirculating aquaculture systems has strong phosphorus removal bacteria,it declares that recirculating aquaculture system provide phosphorus for phosphorus bacteria living.After observing structure of colony,Gram stain and 16 sr DNA,WB,DN,HS and BY is respectively similar to Acinetobacter pittii strain ATCC 19004 ? Shewanella hafniensis strain P010 ? Vibrio vulnificus strain NBRC 15645 ? and Vibrio parahaemolyticus RIMD 2210633 strain O3:K6 by 16 S r RNA,the similarity is 100%?99%?98% and 99%.Phosphorus removal capacity followed WB > HS > DN > BY,total nitrogen removal capacity followed WB > HS =DN > BY=0,Ammonia nitrogen removal capacity followed DN > BY > WB > HS.Phosphorus-accumulating bacteria WB had the best phosphorus removal capacity,rate of phosphorus removal is 44%.By testing the growth curve of WB,there is a stable p Hase in early days,even a little drop of bacterial concentration,after stable p Hase is exponential p Hase.After 20 h,came to stable p Hase,grew fast.Combine with soluble phosphorus content,it found that,rapid growth of bacteria is also the tapid drop of dissoluble phosphorus,it verified WB had a high phosphorus removal capability.WB grew well in p H 6.0-6.5,content of phosphorus 6.5-7.0.When p H >6.5,it grew with the growth of content of phosphorus.Sodium acetate was best for WB growth and removal phosphorus,among sodium citrate,glucose,sucrose malt sugar,and sodium acetate.The most suitable temperature of growth and removal phosphorus in 26?,revolving speed is 120 rpm,the slower revolving speed can inhibition of dissoluble phosphorus.WB can use different form of phosphorus,quickly use dissoluble phosphorus,transform dissoluble inphosphorus,decompose organophosphorus in medium.