Biofl oc technology(BFT)improves water quality,and productivity of the farmed species through converting ammonium nitrogen to microbial protein,stabilizing microbial community,and reducing the production cost.In this ...Biofl oc technology(BFT)improves water quality,and productivity of the farmed species through converting ammonium nitrogen to microbial protein,stabilizing microbial community,and reducing the production cost.In this study,a small-scale biofl oc development unit was designed in combination of recirculation system(RAS)for Artemia culture.Artemia growth,water quality,and microbial composition of biofl ocs in RAS were studied in comparison with in-situ batch culture(Glu).Glucose was added in RAS and Glu at C/N ratio of 10.The cultures without glucose addition,but with 50%daily water renewal(WRe)and without water renewal(NWRe)were considered as the controls.Arte mia were cultured at 25℃ and salinity 30 for 24 days and fed formulated feed.The results showed that compared to the controls,Glu signifi cantly improved the Artemia biomass,increased the biofl oc volume,and reduced the content of total ammonia nitrogen(TAN),nitrite nitrogen(NO_(2)-N)and nitrate nitrogen(NO_(3)-N)in water column(P<0.05).In addition,RAS had similar results with Glu.High throughput sequencing analysis on biofl oc microbial composition demonstrated that glucose supplement shaped the microbial community structure,and increased proportion of potential probiotic bacteria and suppressed pathogenic bacteria growth.Furthermore,we analyzed the relationship between the microbial composition of biofl oc and environmental factors.Canonical correspondence analysis(CCA)indicated that inorganic nitrogen in culture water had great impact on biofl oc microbial composition in NWRe and WRe,whilst the dissolved organic carbon(DOC)modifi ed the microbial community in Glu and RAS.This study shows the advantages of BFT in Artemia culture and provides practical information for applying BFT-RAS in indoor Artemia culture.展开更多
Controlling toxic nitrogenous substances in biofloc technology(BFT)systems is critical for the success of this novel technology.To effectively control nitrogen accumulation in BFT systems,it is important to first unde...Controlling toxic nitrogenous substances in biofloc technology(BFT)systems is critical for the success of this novel technology.To effectively control nitrogen accumulation in BFT systems,it is important to first understand the dynamics and the removal pathways of this element and its related compounds from aquaculture water.This review focuses on synthesizing the information of nitrogen dynamics in BFT systems to provide researchers and practitioners with a guide to the fate of nitrogen and its control methods.This paper discusses the different types of nitrogenous compounds in BFT water,the transformation processes of ammonia to nitrites and nitrates,the relationship between the two forms of ammonia(NH3 and NH4+)in water and the equilibrium between them.This paper also discusses nitrification as a major nitrogen removal pathway and the factors that influence the nitrification process.Notably,the control of nitrogen in BFT systems by manipulating the carbon to nitrogen ratio(C/N)using external carbohydrates is described in this paper.This paper suggests that further studies should focus on investigating the various factors that influence nitrogen dynamics in BFT systems and the means of controlling contaminants other than nitrogen.展开更多
基金Supported by the Yangtze Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT_17R81)the Project of Agricultural intelligence introduction of Tibet(No.2020WZ006)。
文摘Biofl oc technology(BFT)improves water quality,and productivity of the farmed species through converting ammonium nitrogen to microbial protein,stabilizing microbial community,and reducing the production cost.In this study,a small-scale biofl oc development unit was designed in combination of recirculation system(RAS)for Artemia culture.Artemia growth,water quality,and microbial composition of biofl ocs in RAS were studied in comparison with in-situ batch culture(Glu).Glucose was added in RAS and Glu at C/N ratio of 10.The cultures without glucose addition,but with 50%daily water renewal(WRe)and without water renewal(NWRe)were considered as the controls.Arte mia were cultured at 25℃ and salinity 30 for 24 days and fed formulated feed.The results showed that compared to the controls,Glu signifi cantly improved the Artemia biomass,increased the biofl oc volume,and reduced the content of total ammonia nitrogen(TAN),nitrite nitrogen(NO_(2)-N)and nitrate nitrogen(NO_(3)-N)in water column(P<0.05).In addition,RAS had similar results with Glu.High throughput sequencing analysis on biofl oc microbial composition demonstrated that glucose supplement shaped the microbial community structure,and increased proportion of potential probiotic bacteria and suppressed pathogenic bacteria growth.Furthermore,we analyzed the relationship between the microbial composition of biofl oc and environmental factors.Canonical correspondence analysis(CCA)indicated that inorganic nitrogen in culture water had great impact on biofl oc microbial composition in NWRe and WRe,whilst the dissolved organic carbon(DOC)modifi ed the microbial community in Glu and RAS.This study shows the advantages of BFT in Artemia culture and provides practical information for applying BFT-RAS in indoor Artemia culture.
基金This study was funded by the Shanghai Science and Technology Commission Project(19DZ2284300).
文摘Controlling toxic nitrogenous substances in biofloc technology(BFT)systems is critical for the success of this novel technology.To effectively control nitrogen accumulation in BFT systems,it is important to first understand the dynamics and the removal pathways of this element and its related compounds from aquaculture water.This review focuses on synthesizing the information of nitrogen dynamics in BFT systems to provide researchers and practitioners with a guide to the fate of nitrogen and its control methods.This paper discusses the different types of nitrogenous compounds in BFT water,the transformation processes of ammonia to nitrites and nitrates,the relationship between the two forms of ammonia(NH3 and NH4+)in water and the equilibrium between them.This paper also discusses nitrification as a major nitrogen removal pathway and the factors that influence the nitrification process.Notably,the control of nitrogen in BFT systems by manipulating the carbon to nitrogen ratio(C/N)using external carbohydrates is described in this paper.This paper suggests that further studies should focus on investigating the various factors that influence nitrogen dynamics in BFT systems and the means of controlling contaminants other than nitrogen.