In order to explore the effects of different carbon sources on the water of Aristichthys nobilis Richardson culture by biofloc as well as regular,glucose,sucrose,dextrin,brown sugar and molasses 5 soluble carbon sourc...In order to explore the effects of different carbon sources on the water of Aristichthys nobilis Richardson culture by biofloc as well as regular,glucose,sucrose,dextrin,brown sugar and molasses 5 soluble carbon source were added into the water of Aristichthys nobilis Richardson culture containing a certain amount of ammonia nitrogen,nitrite nitrogen to research their effects on pH value,dissolved oxygen,ammonia-nitrogen,nitrite nitrogen value.The results showed that sucrose had the best effect in converting ammonia nitrogen and nitrite nitrogen;glucose and dextrin had significant effect in converting ammonia nitrogen.However,compared with sucrose,glucose and dextrin had bad effect in converting nitrite nitrogen molasses had bad effect in converting ammonia nitrogen and nitrite nitrogen,and had little effect on pH value and dissolved oxygen;glucose,sucrose and dextrin had significant effect in decreasing pH value and dissolved oxygen;brown sugar had good effect in converting nitrite nitrogen,whereas it had little effect in converting ammonia nitrogen.Therefore,sucrose was the best carbon source,and if the cost factor was taken into account,glucose also had a high cost performance.展开更多
1 Introduction Bioflocs is a heterogeneous mixture of the microorganisms,particles,organic polymers and dead cells,etc.(Hargreaves,2006).Among which,heterotrophic bacteria convert efficiently the ammonia nitrogen into...1 Introduction Bioflocs is a heterogeneous mixture of the microorganisms,particles,organic polymers and dead cells,etc.(Hargreaves,2006).Among which,heterotrophic bacteria convert efficiently the ammonia nitrogen into the bacterial protein,which provides the supplementary feed for culture animals and reduces the nitrogen level in the culture system(De Schryver et al,2008).In the closed aquaculture system,the growth of展开更多
Implementation of biofloc technology(BFT)system in aquaculture industry shows high productivity,low feed conversion ratio,and an optimum culture environment.This study was divided into two phases.The first phase invol...Implementation of biofloc technology(BFT)system in aquaculture industry shows high productivity,low feed conversion ratio,and an optimum culture environment.This study was divided into two phases.The first phase involved maintaining the water quality using the optimum carbon-to-nitrogen ratio by manipulating pH in culture water.The second phase examined the performance of harvesting biofloc(remaining phytoplankton and suspended solids in the system)using chicken eggshell powder(CESP).This study showed that pH 7 to 8 were the best biofloc performance with high removal percentage of ammonia(>99%)with a remaining ammonia concentration of 0.016 mg L^(−1)and 0.018 mg L^(−1),respectively.The second phase of this study was performed to determine the optimal formulation and conditions of using CESP as a bio-flocculant in harvesting excess biofloc.The use of eggshell showed a higher harvesting efficiency of more than 80%under the following treatment conditions:0.25 g L^(−1)of eggshell dosage;with rapid and slow mixing rates of 150 and 30 rpm,respectively;30 min of settling time;settling velocity of 0.39 mm s^(−1)and pH of 6 to 7.Therefore,the results indicated that biofloc would be the best green technology approach for sustainable aquaculture wastewater and the CESP is an organic matrix that environmental-friendly bio-coagulant for biofloc harvesting.展开更多
Precocity in tilapia implies the use of several methods of obtaining monosex seed;the most common tends to use masculinizing hormone 17α-methyltestosterone(17αMT),with variable results.Thus the objective of this stu...Precocity in tilapia implies the use of several methods of obtaining monosex seed;the most common tends to use masculinizing hormone 17α-methyltestosterone(17αMT),with variable results.Thus the objective of this study was to compare the efficiency of the sexual reversion process using 17αMT,in a recirculation system and in biofloc.In a totally randomized design,three tanks for recirculation(T-RAS)and three tanks for biofloc(T-BIO)with a capacity of 200 L effective volume were taken and filled with 1,056 larvae of Oreochromis sp.,without reversing and with an initial weight of 0.02 g and an initial total length of 1.4 mm.The study was carried out during 65 d,the fish were fed(10%biomass,adjusted every 15 d)by a commercial diet at 45%of crude protein that included 17αMT(60 mg/kg).Water quality,microbiology,zootechnical and gonadal analysis were monitored.Consequently the water quality results showed that just dissolved oxygen(DO),temperature(T-°C)and alkalinity did not show significant differences.Additionally,in the productive parameters there were significant differences in the final length,the gain in length and in K which were better in T-BIO.The microbiological ones did not present significant differences between the treatments.Lastly,the percentage of reversion was significantly better in T-RAS.Then,this study suggests that settleable solids concentrations above 35 cm decrease the efficiency of the sexual reversion for this species.展开更多
BFT （Biofloc Technology） has been currently applied in Cantho University to a number of targeted species from fresh-to marine and saline water species in the Mekong Delta, e.g. striped catfish （Pangasianodon hypoph...BFT （Biofloc Technology） has been currently applied in Cantho University to a number of targeted species from fresh-to marine and saline water species in the Mekong Delta, e.g. striped catfish （Pangasianodon hypophthalmus）, white leg shrimp （Litopenaeus vannamei）, tiger shrimp （Penaeus monodon） and Artemia Vinhchau strain （Artemia franciscana） for both in the lab-scales or production scales. The best growth and survival rate of striped catfish was obtained in 6%o. For white leg shrimp, the results indicated： （1） C （Carbon） source e.g. rice-flour or molasses supplementary based on the feed provided to promote survival, growth and shrimp biomass harvested; （2） it was fed less than 20% as usual but showed similar to those in the control; （3） combination of rice-flour and molasses at a ratio of 70：30 by weight of C and N （Nitrogen） in a ration of 15：1 enhanced shrimp survival and growth; （4） in intensive culture, shrimp could be against the infection of disease and end up with higher survival, growth in earthen ponds. For tiger shrimp, a set up for larvae till post larvae at different ratios of C and N and C：N of 30 PLI5 displayed with better survival rate （49.73 ± 7.07%） and production （74,596 ± 10.608 PL/m3）. Artemiafranciscana was set up at C：N = 10：1 and salinities from 35, 60, 80 and 100 ppt. After two weeks, there were no significant difference among treatment and the control （without biofloc） in term of survival and growth. Moreover, total embryos per female was not significant different with the control and even the number of embryos as cysts tended to be higher. BFT displayed its advantages when applied on culture system of different targeted species and there is no doubt that it could help to sustain aquaculture and save environment in the Mekong Delta in near future.展开更多
Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces...Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces the nitrogen level in the water and provides microbial protein to the animals. However, most of the studies and practical applications have been conducted in freshwater and marine environment. This paper focused on brine shrimp Artemia that lives in high salinity environment together with other halophilic or halotolerant microorganisms. The effect of carbon supplementation on Artemia growth, water quality, and microbial diversity of biofl ocs was studied in the closed culture condition without any water exchange. The salinity of the culture medium was 100. A 24-d culture trial was conducted through supplementing sucrose at carbon/nitrogen (C/N) ratio of 5, 15, and 30 (Su5, Su15, and Su30), respectively. The culture without adding sucrose was used as a control. Artemia was fed formulated feed at a feeding ration of 60% recommended feeding level. The results showed that sucrose supplementation at higher C/N ratio (15 and 30) signifi cantly improved the Artemia survival, growth and water quality ( P <0.05). Addition of sucrose at C/N ratio of 15 and 30 significantly increased biofloc volume (BFV)( P <0.05). The Illumina MiSeq sequencing analysis showed that supplementing carbon at C/N ratio of 15 had a better total bacterial diversity and richness, and shaped the microbial composition at genera level. This study should provide information for studying the mechanism of biofloc technology and its application in high salinity culture conditions.展开更多
The objective of this study was to analyze the stomach composition of Penaeus vannamei shrimp in biofloc cultures with varying percentages of reused bioflocs to identify the optimal culture conditions based on microor...The objective of this study was to analyze the stomach composition of Penaeus vannamei shrimp in biofloc cultures with varying percentages of reused bioflocs to identify the optimal culture conditions based on microorganism content.Four treatments were employed:clear water(CW),25%biofloc inoculum(BF 25%),50%biofloc inoculum(BF 50%),and 100%biofloc inoculum(BF 100%).Bioflocs were reused from mature bioflocs of previous cultures in biofloc treatments.Shrimp performance was monitored weekly through biometrics,and stomach samples were collected at the experiment's onset and conclusion.The samples underwent fixation in 4%formaldehyde for subsequent counting and identification of predominant microorganism groups using an inverted microscope.Bacterial abundance was assessed by fixing,filtering,and staining samples with acridine orange,followed by quantification with an epifluorescence microscope.Water quality parameters remained satisfactory in all treatments.Shrimp stomachs in biofloc systems contained Oocystis sp.,ciliates,flagellates,diatoms,free coccoids,free and attached filamentous,Bacillus spp.,and Vibrio spp.CW treatment exhibited the highest Vibrio spp.concentration.Overall,reusing bioflocs in all volume percentages effectively maintained water quality and colonized the animal's microbiota,with a recommended minimum reuse percentage of 25%for satisfactory results.展开更多
This research embarked upon an in-depth exploration of the pioneering concept of biofloc biosecurity,assessing its instrumental role in amplifying fish growth dynamics,hematological indices,biochemical metrics,chemica...This research embarked upon an in-depth exploration of the pioneering concept of biofloc biosecurity,assessing its instrumental role in amplifying fish growth dynamics,hematological indices,biochemical metrics,chemical body composition,and immunological defenses,both pre-and post-infection by Aeromonas hydrophila.By juxtaposing biofloc-reared Oreochromis niloticus against traditionally reared fish,intricate observations of histopathological changes and clinical symptomatology were undertaken.Employing 16S RNA,the bacterial strain Aeromonas hydrophila(ATCC 7966)was precisely identified and banked It into gene bank and given accession number(OR452335).After a preparatory period of ten weeks in the Biofloc system,O.niloticus faced a challenge with Aeromonas hydrophila.Empirical findings revealed that fish from the Biofloc cohort displayed marked advancements across all investigational parameters,before and after infection,as opposed to the control set.In the aftermath of the Aeromonas hydrophila confrontation,biofloc-acclimatized fish manifested an elevated resilience against the bacterial onslaught,displaying superior metrics in growth,hematology,biochemistry,body constitution,and immunological response.Biofloc group showed a strong immune response,particularly in terms of Lysozyme and Total Antioxidant Capacity.Additionally,there was a significant impact on Immunoglobulin and Complement 3 after infection,highlighting the group's increased immune activity.Furthermore,these fish attenuated the pernicious morphological indicators and histopathological anomalies instigated by septicemic bacteria,which otherwise inflict substantial economic detriments upon the aquaculture industry.This research underscores the immense promise biofloc biosecurity holds in bolstering the overall health and performance metrics of cultured O.niloticus.展开更多
This study presents a bioeconomic model after analyzing the commercial profitability of Nile tilapia under biofloc(BFT)and green water(GWT)technologies.Environmental stochasticity was evaluated using the parameters ob...This study presents a bioeconomic model after analyzing the commercial profitability of Nile tilapia under biofloc(BFT)and green water(GWT)technologies.Environmental stochasticity was evaluated using the parameters obtained in Yucatan’s rainy(RN)and dry(DR)seasons.The productive impact was measured by analyzing the 10-year cash flow.Both systems demonstrated profitability with a positive NPV and 450 g harvest weight in the short term.The unit cost of production results for the GWT was lower than for the BFT.The long-term simulation involved an investment of $410,279 USD for 30 tanks,resulting in a positive return for GWT.BFT showed negative long-term profitability at the current selling price($2.36 USD/kg).Profitability improved as the sales price increased by 11% and 22% for RN-BFT and DR-BFT,respectively.This bioeconomic model is pioneering in tilapia production in BFT and GWT and provides valuable data to achieve better yield and profitability.展开更多
This study investigated the effects of reusing biofloc-culture water for culturing the white-leg shrimp Litopenaeus vannamei.Experiments were conducted for two continuous cycles without water exchange for 30 days duri...This study investigated the effects of reusing biofloc-culture water for culturing the white-leg shrimp Litopenaeus vannamei.Experiments were conducted for two continuous cycles without water exchange for 30 days during the nursery stage.The studies were performed with two different aeration systems,namely microbubbles(MB)and large air bubbles(LB).Water quality parameters such as dissolved oxygen(DO),temperature,pH,salinity,alkalinity,total ammonia nitrogen(TAN),nitrite,nitrate,settleable solids(SS),and total suspended solids(TSS)were recorded throughout the culture days.Also,comparisons were performed on parameters of the shrimp growth,i.e.,body weight and length,feed conversion ratio(FCR),and specific growth rates(SGR)for the 30-day culture for Cycles 1 and 2.Cycle 2 showed no deterioration in water quality and no significant difference in growth performance compared to Cycle 1 for either aeration method(MB and LB).However,when comparing between aeration methods,MB aeration significantly improved the DO of the water and accelerated the conversion of TAN to nitrate.Shrimps in the MB aeration system were significantly larger(by 39%)with a lower FCR value(reduced by 30%)than in the LB aeration system.Harmful bacteria from the Vibro group were detected.However,they occurred at a minimum level in both cycles and aeration types.Overall,the biofloc-culture water might be reused for the subsequent cycle,while the MB aeration might promote the growth of biofloc and L.vannamei.展开更多
Recirculating Aquaculture System(RAS)is introduced in aquaculture farming industry to reduce water resource utilization,efficient the energy and land uses,and also help minimalize the water exchange.This system enable...Recirculating Aquaculture System(RAS)is introduced in aquaculture farming industry to reduce water resource utilization,efficient the energy and land uses,and also help minimalize the water exchange.This system enables utilization of unsuitable land and promotes a sustainable environment in aquaculture industry.Furthermore,this technology has been established and proved efficient in monitoring the aquatic animal condition subsequently helps in maintaining the water quality and help remove solid particle wastes from the aquaculture treatment.As today,RAS has been developed with more effective technologies such as the use of UV irradiation,solid capture,protein skimmer and also provided with highly techno bio-filtration set.Basically,this system was applied for broodstock maturation,nursery phase,and grow-out production.In this review article,we provide an overview of RAS between the clear water,probiotic,and biofloc technology,and the advantages of its combination.Even though RAS and biofloc is two different parallel system,the application of the probiotic and biofloc in the semi-RAS application system is intense to be investigated.The synergistic effect of RAS using this combination towards high yield aquaculture production will be highlighted in this review paper.Expectantly this review paper will generate awareness and useful information on the RAS application in the aquaculture system operation with help in maximize the impact to the aquaculture yield production.展开更多
In recirculating aquaculture systems,nitrification is usually accelerated by inoculating nitrifier or mature biocarriers.In this study,the performance of the establishment of nitrification in the MBBR according to thr...In recirculating aquaculture systems,nitrification is usually accelerated by inoculating nitrifier or mature biocarriers.In this study,the performance of the establishment of nitrification in the MBBR according to three different strategies:conventional method(Control group A),inoculation with biofloc recovered from a tilapia biofloc culture system(Group B),and addition with extra nitrite(Group C)in the Moving bed biofilm reactor(MBBR)was compared.Among them,the biofloc-inoculated group considerably accelerated the nitrification process in the MBBR(38 d),which is roughly 18 d faster than the control group(A)(56 d)and 21 d faster than group C(59 d).Less ammonia(8 mg/L NH_(4)^(+)-N,10 mg/L in other groups)and external nitrite(2 mg/L NO_(2)^(-)N)in the influent caused effluent ammonia to drop more slowly(5 d slower than the control group,8 d slower than the B group),which is detrimental to the nitrification process’development.Notably,the influent’s hydraulic retention time(HRT)was reduced from 12 h to 6 h following the successful establishment of nitrification.During the adaptation to reduced HRT,the MBBR inoculated with biofloc experienced short-term changes in the water quality index of the effluent water,whereas the other groups did not.The biofilm seeded with biofloc had the highest mean gray value ratio(1.42)of live/dead cell fluorescence,which grew better and could cover the entire groove under multiple microscope observations.However,the other groups did not demonstrate a similar trend.In summary,the research found that seeding biofloc use as nitrification bioaugmentation into the MBBR of the recirculating aquaculture system(RAS)to greatly speed up the nitrification process.展开更多
The growth of aquaculture demands intense consumption of formulated foods,scarce natural resources such as water and land.The increase in aquaculture production needs to be sustainable in several aspects of the activi...The growth of aquaculture demands intense consumption of formulated foods,scarce natural resources such as water and land.The increase in aquaculture production needs to be sustainable in several aspects of the activity,including the use of more sustainable farming systems that provide reduced water demand,less space dependence for increased production,and availability of complementary natural food.In this perspective,the biofloc system(BFT),presents itself as a more friendly cultivation technology as a way to mitigate some impacts of aquaculture production.Much research has been carried out,addressing different aspects important to the production of fish in BFT.In this review,we address how stocking density,carbon sources and carbon nitrogen ration(C/N)affect animal performance and the nutritional value of bioflocs;the use of microbial aggregates as“in situ”and“ex situ”food and the benefits in feed conversion,and their influence on the immune system and disease resistance.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
This study aimed to evaluate the supplementation of the probiotic Pseudoalteromonas piscicida 1Ub to the biofloc system as an ecofriendly strategy for protecting white shrimp(Penaeus vannamei)from Vibrio parahaemolyti...This study aimed to evaluate the supplementation of the probiotic Pseudoalteromonas piscicida 1Ub to the biofloc system as an ecofriendly strategy for protecting white shrimp(Penaeus vannamei)from Vibrio parahaemolyticus infection.Shrimp with an average body weight of(0.50±0.09)g were reared in 30 glass jars with a working volume of 2.5 L at a density of 20 ind/L.Shrimp were reared for 5 d for each treatment,which included the biofloc system without and with 106 colony forming unit(CFU)per mL probiotic.The regular clear water system was used as control.All treatment groups were challenged with 103,105,and 107 CFU/mL V.parahaemolyticus.For the negative control,shrimp were reared without V.parahaemolyticus.The results showed that the density of V.parahaemolyticus cocultured with P.piscicida 1Ub decreased and the density of V.parahaemolyticus in rearing water and shrimp body in the probiotic-treated group was lower than that in the control group(P<0.05).The survival and immune response(total hemocyte count,phagocytic activity,respiratory burst,phenoloxidase,and superoxide dismutase)of shrimp in the probiotic group was higher than that in the positive control(P<0.05).Moreover,supplementing the biofloc system with the probiotic could protect shrimp hepatopancreas from damage caused by V.parahaemolyticus,regardless of bacterial density.Thus,the supplementation of the probiotic P.piscicida 1Ub in the biofloc system could significantly protect and increase the resistance of shrimp to V.parahaemolyticus infection.展开更多
The production of bioflocs with the solid waste from recirculating aquaculture systems(RAS)and feeding Artemia results in additional nutrient retention and lowers waste discharged from RAS.The solid waste from the dru...The production of bioflocs with the solid waste from recirculating aquaculture systems(RAS)and feeding Artemia results in additional nutrient retention and lowers waste discharged from RAS.The solid waste from the drumfilters of two RAS,which stocked European eel(Anguilla anguilla)and Nile tilapia(Oreochromis niloticus),was used as substrate to produce bioflocs in suspended growth reactors,referred to as E-flocs and T-flocs,respectively.Mono-diets consisting of 100%E-flocs and 100%T-flocs were added to culture Artemia,referred as E-Artemia and T-Artemia,respectively,in a laboratory scale test.The efficiency of this feeding regime was investigated.A significant difference was observed in terms of crude protein content(35.59±0.2%)for E-flocs,(29.29±0.95)%for T-flocs,(70.01±0.92)%for E-Artemia and(65.63±0.89)%for T-Artemia.134 out of the total operational taxonomic units(OTUs)were present in E-flocs and T-flocs from the analysis of high-throughput sequencing data.Most of the shared OTUs belonged to cyanobacteria.C18:1n7 of T-flocs was higher than that of E-flocs(P<0.05).C18:2n6 of E-flocs was significantly higher than that of T-flocs(P<0.05).No significant difference was observed in the other fatty acid compositions(P>0.05).The survival rate of E-Artemia was(22±0.02)%,significantly higher than that of T-Artemia(16%±0.02%)(P<0.05).No significant difference was observed between the average body weight of E-Artemia(2.38±0.40 mg)and E-Artemia(2.91±0.21)(P>0.05).The EPA of Artemia fed with E-flocs was(3.00±0.46)%,significantly higher than that of T-Artemia(1.57±0.19%)(P<0.05).This study offers a method for reusing the aquaculture waste,which will be helpful to achieve a zero-pollution discharge for aquaculture systems.展开更多
文摘In order to explore the effects of different carbon sources on the water of Aristichthys nobilis Richardson culture by biofloc as well as regular,glucose,sucrose,dextrin,brown sugar and molasses 5 soluble carbon source were added into the water of Aristichthys nobilis Richardson culture containing a certain amount of ammonia nitrogen,nitrite nitrogen to research their effects on pH value,dissolved oxygen,ammonia-nitrogen,nitrite nitrogen value.The results showed that sucrose had the best effect in converting ammonia nitrogen and nitrite nitrogen;glucose and dextrin had significant effect in converting ammonia nitrogen.However,compared with sucrose,glucose and dextrin had bad effect in converting nitrite nitrogen molasses had bad effect in converting ammonia nitrogen and nitrite nitrogen,and had little effect on pH value and dissolved oxygen;glucose,sucrose and dextrin had significant effect in decreasing pH value and dissolved oxygen;brown sugar had good effect in converting nitrite nitrogen,whereas it had little effect in converting ammonia nitrogen.Therefore,sucrose was the best carbon source,and if the cost factor was taken into account,glucose also had a high cost performance.
基金supported by the International Cooperation Research Program of the Ministry of Science & Technology of China (2010DFA32300)Natural Science Foundation of Tianjin City (13JCZDJC28700)China and the Pilot Project for International Cooperation funded by the Province of East-Flanders, Belgium
文摘1 Introduction Bioflocs is a heterogeneous mixture of the microorganisms,particles,organic polymers and dead cells,etc.(Hargreaves,2006).Among which,heterotrophic bacteria convert efficiently the ammonia nitrogen into the bacterial protein,which provides the supplementary feed for culture animals and reduces the nitrogen level in the culture system(De Schryver et al,2008).In the closed aquaculture system,the growth of
文摘Implementation of biofloc technology(BFT)system in aquaculture industry shows high productivity,low feed conversion ratio,and an optimum culture environment.This study was divided into two phases.The first phase involved maintaining the water quality using the optimum carbon-to-nitrogen ratio by manipulating pH in culture water.The second phase examined the performance of harvesting biofloc(remaining phytoplankton and suspended solids in the system)using chicken eggshell powder(CESP).This study showed that pH 7 to 8 were the best biofloc performance with high removal percentage of ammonia(>99%)with a remaining ammonia concentration of 0.016 mg L^(−1)and 0.018 mg L^(−1),respectively.The second phase of this study was performed to determine the optimal formulation and conditions of using CESP as a bio-flocculant in harvesting excess biofloc.The use of eggshell showed a higher harvesting efficiency of more than 80%under the following treatment conditions:0.25 g L^(−1)of eggshell dosage;with rapid and slow mixing rates of 150 and 30 rpm,respectively;30 min of settling time;settling velocity of 0.39 mm s^(−1)and pH of 6 to 7.Therefore,the results indicated that biofloc would be the best green technology approach for sustainable aquaculture wastewater and the CESP is an organic matrix that environmental-friendly bio-coagulant for biofloc harvesting.
文摘Precocity in tilapia implies the use of several methods of obtaining monosex seed;the most common tends to use masculinizing hormone 17α-methyltestosterone(17αMT),with variable results.Thus the objective of this study was to compare the efficiency of the sexual reversion process using 17αMT,in a recirculation system and in biofloc.In a totally randomized design,three tanks for recirculation(T-RAS)and three tanks for biofloc(T-BIO)with a capacity of 200 L effective volume were taken and filled with 1,056 larvae of Oreochromis sp.,without reversing and with an initial weight of 0.02 g and an initial total length of 1.4 mm.The study was carried out during 65 d,the fish were fed(10%biomass,adjusted every 15 d)by a commercial diet at 45%of crude protein that included 17αMT(60 mg/kg).Water quality,microbiology,zootechnical and gonadal analysis were monitored.Consequently the water quality results showed that just dissolved oxygen(DO),temperature(T-°C)and alkalinity did not show significant differences.Additionally,in the productive parameters there were significant differences in the final length,the gain in length and in K which were better in T-BIO.The microbiological ones did not present significant differences between the treatments.Lastly,the percentage of reversion was significantly better in T-RAS.Then,this study suggests that settleable solids concentrations above 35 cm decrease the efficiency of the sexual reversion for this species.
文摘BFT （Biofloc Technology） has been currently applied in Cantho University to a number of targeted species from fresh-to marine and saline water species in the Mekong Delta, e.g. striped catfish （Pangasianodon hypophthalmus）, white leg shrimp （Litopenaeus vannamei）, tiger shrimp （Penaeus monodon） and Artemia Vinhchau strain （Artemia franciscana） for both in the lab-scales or production scales. The best growth and survival rate of striped catfish was obtained in 6%o. For white leg shrimp, the results indicated： （1） C （Carbon） source e.g. rice-flour or molasses supplementary based on the feed provided to promote survival, growth and shrimp biomass harvested; （2） it was fed less than 20% as usual but showed similar to those in the control; （3） combination of rice-flour and molasses at a ratio of 70：30 by weight of C and N （Nitrogen） in a ration of 15：1 enhanced shrimp survival and growth; （4） in intensive culture, shrimp could be against the infection of disease and end up with higher survival, growth in earthen ponds. For tiger shrimp, a set up for larvae till post larvae at different ratios of C and N and C：N of 30 PLI5 displayed with better survival rate （49.73 ± 7.07%） and production （74,596 ± 10.608 PL/m3）. Artemiafranciscana was set up at C：N = 10：1 and salinities from 35, 60, 80 and 100 ppt. After two weeks, there were no significant difference among treatment and the control （without biofloc） in term of survival and growth. Moreover, total embryos per female was not significant different with the control and even the number of embryos as cysts tended to be higher. BFT displayed its advantages when applied on culture system of different targeted species and there is no doubt that it could help to sustain aquaculture and save environment in the Mekong Delta in near future.
基金Supported by the Yangtze Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT_17R81)the Technology Support Project of Tianjin(No.16YFZCNC00810)
文摘Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces the nitrogen level in the water and provides microbial protein to the animals. However, most of the studies and practical applications have been conducted in freshwater and marine environment. This paper focused on brine shrimp Artemia that lives in high salinity environment together with other halophilic or halotolerant microorganisms. The effect of carbon supplementation on Artemia growth, water quality, and microbial diversity of biofl ocs was studied in the closed culture condition without any water exchange. The salinity of the culture medium was 100. A 24-d culture trial was conducted through supplementing sucrose at carbon/nitrogen (C/N) ratio of 5, 15, and 30 (Su5, Su15, and Su30), respectively. The culture without adding sucrose was used as a control. Artemia was fed formulated feed at a feeding ration of 60% recommended feeding level. The results showed that sucrose supplementation at higher C/N ratio (15 and 30) signifi cantly improved the Artemia survival, growth and water quality ( P <0.05). Addition of sucrose at C/N ratio of 15 and 30 significantly increased biofloc volume (BFV)( P <0.05). The Illumina MiSeq sequencing analysis showed that supplementing carbon at C/N ratio of 15 had a better total bacterial diversity and richness, and shaped the microbial composition at genera level. This study should provide information for studying the mechanism of biofloc technology and its application in high salinity culture conditions.
基金support provided by the National Council for Scientific and Technological.Development(CNPq,process number:307741/2022-2 and 313514/2023-2)Foundation for Research.Support of the State of Rio Grande do Sul–FAPERGS(process number:21/2551-5050002225-6 and 17/2551-0000955-0)the Coordination for the Improvement of Higher Education Personnel(CAPES,process number:88887.595816/2020–00,88887.612993/2021-00,and 88887.826108/2023-00.
文摘The objective of this study was to analyze the stomach composition of Penaeus vannamei shrimp in biofloc cultures with varying percentages of reused bioflocs to identify the optimal culture conditions based on microorganism content.Four treatments were employed:clear water(CW),25%biofloc inoculum(BF 25%),50%biofloc inoculum(BF 50%),and 100%biofloc inoculum(BF 100%).Bioflocs were reused from mature bioflocs of previous cultures in biofloc treatments.Shrimp performance was monitored weekly through biometrics,and stomach samples were collected at the experiment's onset and conclusion.The samples underwent fixation in 4%formaldehyde for subsequent counting and identification of predominant microorganism groups using an inverted microscope.Bacterial abundance was assessed by fixing,filtering,and staining samples with acridine orange,followed by quantification with an epifluorescence microscope.Water quality parameters remained satisfactory in all treatments.Shrimp stomachs in biofloc systems contained Oocystis sp.,ciliates,flagellates,diatoms,free coccoids,free and attached filamentous,Bacillus spp.,and Vibrio spp.CW treatment exhibited the highest Vibrio spp.concentration.Overall,reusing bioflocs in all volume percentages effectively maintained water quality and colonized the animal's microbiota,with a recommended minimum reuse percentage of 25%for satisfactory results.
文摘This research embarked upon an in-depth exploration of the pioneering concept of biofloc biosecurity,assessing its instrumental role in amplifying fish growth dynamics,hematological indices,biochemical metrics,chemical body composition,and immunological defenses,both pre-and post-infection by Aeromonas hydrophila.By juxtaposing biofloc-reared Oreochromis niloticus against traditionally reared fish,intricate observations of histopathological changes and clinical symptomatology were undertaken.Employing 16S RNA,the bacterial strain Aeromonas hydrophila(ATCC 7966)was precisely identified and banked It into gene bank and given accession number(OR452335).After a preparatory period of ten weeks in the Biofloc system,O.niloticus faced a challenge with Aeromonas hydrophila.Empirical findings revealed that fish from the Biofloc cohort displayed marked advancements across all investigational parameters,before and after infection,as opposed to the control set.In the aftermath of the Aeromonas hydrophila confrontation,biofloc-acclimatized fish manifested an elevated resilience against the bacterial onslaught,displaying superior metrics in growth,hematology,biochemistry,body constitution,and immunological response.Biofloc group showed a strong immune response,particularly in terms of Lysozyme and Total Antioxidant Capacity.Additionally,there was a significant impact on Immunoglobulin and Complement 3 after infection,highlighting the group's increased immune activity.Furthermore,these fish attenuated the pernicious morphological indicators and histopathological anomalies instigated by septicemic bacteria,which otherwise inflict substantial economic detriments upon the aquaculture industry.This research underscores the immense promise biofloc biosecurity holds in bolstering the overall health and performance metrics of cultured O.niloticus.
基金the National Council of Science and Technology(CONACYT)for the Ph.D.scholarship granted to BSP(grant number 297693/633432).
文摘This study presents a bioeconomic model after analyzing the commercial profitability of Nile tilapia under biofloc(BFT)and green water(GWT)technologies.Environmental stochasticity was evaluated using the parameters obtained in Yucatan’s rainy(RN)and dry(DR)seasons.The productive impact was measured by analyzing the 10-year cash flow.Both systems demonstrated profitability with a positive NPV and 450 g harvest weight in the short term.The unit cost of production results for the GWT was lower than for the BFT.The long-term simulation involved an investment of $410,279 USD for 30 tanks,resulting in a positive return for GWT.BFT showed negative long-term profitability at the current selling price($2.36 USD/kg).Profitability improved as the sales price increased by 11% and 22% for RN-BFT and DR-BFT,respectively.This bioeconomic model is pioneering in tilapia production in BFT and GWT and provides valuable data to achieve better yield and profitability.
基金funded by Universiti Malaya Impact-oriented Interdisciplinary Research Grant(IIRG005A-2020IISS)ERSRC:RCUK-SEA Newton Small Scale Partnership(No:IF022-2017).
文摘This study investigated the effects of reusing biofloc-culture water for culturing the white-leg shrimp Litopenaeus vannamei.Experiments were conducted for two continuous cycles without water exchange for 30 days during the nursery stage.The studies were performed with two different aeration systems,namely microbubbles(MB)and large air bubbles(LB).Water quality parameters such as dissolved oxygen(DO),temperature,pH,salinity,alkalinity,total ammonia nitrogen(TAN),nitrite,nitrate,settleable solids(SS),and total suspended solids(TSS)were recorded throughout the culture days.Also,comparisons were performed on parameters of the shrimp growth,i.e.,body weight and length,feed conversion ratio(FCR),and specific growth rates(SGR)for the 30-day culture for Cycles 1 and 2.Cycle 2 showed no deterioration in water quality and no significant difference in growth performance compared to Cycle 1 for either aeration method(MB and LB).However,when comparing between aeration methods,MB aeration significantly improved the DO of the water and accelerated the conversion of TAN to nitrate.Shrimps in the MB aeration system were significantly larger(by 39%)with a lower FCR value(reduced by 30%)than in the LB aeration system.Harmful bacteria from the Vibro group were detected.However,they occurred at a minimum level in both cycles and aeration types.Overall,the biofloc-culture water might be reused for the subsequent cycle,while the MB aeration might promote the growth of biofloc and L.vannamei.
基金the HICoE outcome project entitle"Indoor Multi-Techno Aquaculture System(IMTAS)",funded by the Ministry of Higher Education(MOHE),Malaysia under Higher Institution Centre of Excellence(HICoE),Institute of Tropical Aquaculture and Fisheries(AKUATROP),Universiti Malaysia Terengganu program[Vot.No.63933,JPT.S(BPKI)2000/016/018/015Jld.3(23)and Vot.No.56050,UMT/PPPI-2-2/5 Jld.2(24)].
文摘Recirculating Aquaculture System(RAS)is introduced in aquaculture farming industry to reduce water resource utilization,efficient the energy and land uses,and also help minimalize the water exchange.This system enables utilization of unsuitable land and promotes a sustainable environment in aquaculture industry.Furthermore,this technology has been established and proved efficient in monitoring the aquatic animal condition subsequently helps in maintaining the water quality and help remove solid particle wastes from the aquaculture treatment.As today,RAS has been developed with more effective technologies such as the use of UV irradiation,solid capture,protein skimmer and also provided with highly techno bio-filtration set.Basically,this system was applied for broodstock maturation,nursery phase,and grow-out production.In this review article,we provide an overview of RAS between the clear water,probiotic,and biofloc technology,and the advantages of its combination.Even though RAS and biofloc is two different parallel system,the application of the probiotic and biofloc in the semi-RAS application system is intense to be investigated.The synergistic effect of RAS using this combination towards high yield aquaculture production will be highlighted in this review paper.Expectantly this review paper will generate awareness and useful information on the RAS application in the aquaculture system operation with help in maximize the impact to the aquaculture yield production.
基金the Shanghai Municipal Science and Technology Commission Project(19DZ2284300).
文摘In recirculating aquaculture systems,nitrification is usually accelerated by inoculating nitrifier or mature biocarriers.In this study,the performance of the establishment of nitrification in the MBBR according to three different strategies:conventional method(Control group A),inoculation with biofloc recovered from a tilapia biofloc culture system(Group B),and addition with extra nitrite(Group C)in the Moving bed biofilm reactor(MBBR)was compared.Among them,the biofloc-inoculated group considerably accelerated the nitrification process in the MBBR(38 d),which is roughly 18 d faster than the control group(A)(56 d)and 21 d faster than group C(59 d).Less ammonia(8 mg/L NH_(4)^(+)-N,10 mg/L in other groups)and external nitrite(2 mg/L NO_(2)^(-)N)in the influent caused effluent ammonia to drop more slowly(5 d slower than the control group,8 d slower than the B group),which is detrimental to the nitrification process’development.Notably,the influent’s hydraulic retention time(HRT)was reduced from 12 h to 6 h following the successful establishment of nitrification.During the adaptation to reduced HRT,the MBBR inoculated with biofloc experienced short-term changes in the water quality index of the effluent water,whereas the other groups did not.The biofilm seeded with biofloc had the highest mean gray value ratio(1.42)of live/dead cell fluorescence,which grew better and could cover the entire groove under multiple microscope observations.However,the other groups did not demonstrate a similar trend.In summary,the research found that seeding biofloc use as nitrification bioaugmentation into the MBBR of the recirculating aquaculture system(RAS)to greatly speed up the nitrification process.
文摘The growth of aquaculture demands intense consumption of formulated foods,scarce natural resources such as water and land.The increase in aquaculture production needs to be sustainable in several aspects of the activity,including the use of more sustainable farming systems that provide reduced water demand,less space dependence for increased production,and availability of complementary natural food.In this perspective,the biofloc system(BFT),presents itself as a more friendly cultivation technology as a way to mitigate some impacts of aquaculture production.Much research has been carried out,addressing different aspects important to the production of fish in BFT.In this review,we address how stocking density,carbon sources and carbon nitrogen ration(C/N)affect animal performance and the nutritional value of bioflocs;the use of microbial aggregates as“in situ”and“ex situ”food and the benefits in feed conversion,and their influence on the immune system and disease resistance.
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.
基金financially supported by the Ministry of Education,Culture,Research,and Technology of the Republic of Indonesia for funding the present study in the form of the Pendidikan Magister menuju Doktor untuk Sarjana Unggul(PMDSU)program scholarship(Grant number:200/SP2H/PMDSU/DRPM/2020).
文摘This study aimed to evaluate the supplementation of the probiotic Pseudoalteromonas piscicida 1Ub to the biofloc system as an ecofriendly strategy for protecting white shrimp(Penaeus vannamei)from Vibrio parahaemolyticus infection.Shrimp with an average body weight of(0.50±0.09)g were reared in 30 glass jars with a working volume of 2.5 L at a density of 20 ind/L.Shrimp were reared for 5 d for each treatment,which included the biofloc system without and with 106 colony forming unit(CFU)per mL probiotic.The regular clear water system was used as control.All treatment groups were challenged with 103,105,and 107 CFU/mL V.parahaemolyticus.For the negative control,shrimp were reared without V.parahaemolyticus.The results showed that the density of V.parahaemolyticus cocultured with P.piscicida 1Ub decreased and the density of V.parahaemolyticus in rearing water and shrimp body in the probiotic-treated group was lower than that in the control group(P<0.05).The survival and immune response(total hemocyte count,phagocytic activity,respiratory burst,phenoloxidase,and superoxide dismutase)of shrimp in the probiotic group was higher than that in the positive control(P<0.05).Moreover,supplementing the biofloc system with the probiotic could protect shrimp hepatopancreas from damage caused by V.parahaemolyticus,regardless of bacterial density.Thus,the supplementation of the probiotic P.piscicida 1Ub in the biofloc system could significantly protect and increase the resistance of shrimp to V.parahaemolyticus infection.
基金This study was funded by the Shanghai Science and Technology Commission Project(16DZ2281200).
文摘The production of bioflocs with the solid waste from recirculating aquaculture systems(RAS)and feeding Artemia results in additional nutrient retention and lowers waste discharged from RAS.The solid waste from the drumfilters of two RAS,which stocked European eel(Anguilla anguilla)and Nile tilapia(Oreochromis niloticus),was used as substrate to produce bioflocs in suspended growth reactors,referred to as E-flocs and T-flocs,respectively.Mono-diets consisting of 100%E-flocs and 100%T-flocs were added to culture Artemia,referred as E-Artemia and T-Artemia,respectively,in a laboratory scale test.The efficiency of this feeding regime was investigated.A significant difference was observed in terms of crude protein content(35.59±0.2%)for E-flocs,(29.29±0.95)%for T-flocs,(70.01±0.92)%for E-Artemia and(65.63±0.89)%for T-Artemia.134 out of the total operational taxonomic units(OTUs)were present in E-flocs and T-flocs from the analysis of high-throughput sequencing data.Most of the shared OTUs belonged to cyanobacteria.C18:1n7 of T-flocs was higher than that of E-flocs(P<0.05).C18:2n6 of E-flocs was significantly higher than that of T-flocs(P<0.05).No significant difference was observed in the other fatty acid compositions(P>0.05).The survival rate of E-Artemia was(22±0.02)%,significantly higher than that of T-Artemia(16%±0.02%)(P<0.05).No significant difference was observed between the average body weight of E-Artemia(2.38±0.40 mg)and E-Artemia(2.91±0.21)(P>0.05).The EPA of Artemia fed with E-flocs was(3.00±0.46)%,significantly higher than that of T-Artemia(1.57±0.19%)(P<0.05).This study offers a method for reusing the aquaculture waste,which will be helpful to achieve a zero-pollution discharge for aquaculture systems.
