Microplastics(MPs)are one of the most concerning pollutants that affects the health and growth of aquatic organisms.We characterized the MPs dispersion in the milli-Q water and seawater,and evaluated the effects of MP...Microplastics(MPs)are one of the most concerning pollutants that affects the health and growth of aquatic organisms.We characterized the MPs dispersion in the milli-Q water and seawater,and evaluated the effects of MPs on the gut epithelial cells of brine shrimp using three sizes of polystyrene(PS)microbeads(0.05,0.5,and 5μm,respectively).Results show that microbeads evenly dispersed in milli-Q water,but exhibited aggregation tendency in seawater associating with the particle size.Apart from a reduced survival rate,we observed the structure changes in the gut epithelium that the smaller size of PS microbeads resulted in an increased reactive oxygen species(ROS)and higher apoptosis-related genes expression.Moreover,exposure to all size of PS microbeads led to increased green fluorescence of J-monomer,indicating the declined mitochondrial membrane potential.Therefore,exposure to PS microbeads led to significantly size-dependent toxicity on brine shrimp.Especially,0.05-μm PS microbeads were more toxic,leading to severe oxidative stress and activation of the p53-Bax-Bcl2 pathway,ultimately resulting in cellular apoptosis and gut damage.These findings are important to understand the mechanism of MPs toxicity and its potential ecological risks to marine aquatic animals.展开更多
5-hydroxytryptamine(5-HT)is a biological monoamine neurotransmitter in the central nervous system and gonads of crustaceans to induce gonadal maturation.To better understand the effects of 5-HT and its receptors on re...5-hydroxytryptamine(5-HT)is a biological monoamine neurotransmitter in the central nervous system and gonads of crustaceans to induce gonadal maturation.To better understand the effects of 5-HT and its receptors on reproductive development in Artemia,a 5-HT type 7 receptor gene(5-HT_(7Ar))was identified in parthenogenetic Artemia and characterized.Sequence analysis revealed that the open reading frame of 5-HT_(7Ar) encodes a 414-aa protein.5-HT_(7Ar) showed higher expression in both brain and ovary at early embryo stage,5-HT_(7Ar) could be detected during ovarian development and the highest expression was observed at early embryo stage.Silencing of the 5-HT_(7Ar) in Artemia at early embryo stage decreased significantly the expression level of 5-HT_(7Ar) gene and protein at late oocyte,early embryo,and late embryo stage.Moreover,silencing of the 5-HT_(7Ar) resulted in a decreased fecundity,which corresponds to abnormal oocytes during the embryo development.Artemia tended to produce nauplii after the silencing of 5-HT_(7Ar),indicating that 5-HT_(7Ar) may also involve in the determination of its reproduction mode.The findings of this study provide an insight into the regulation of reproductive development in Artemia and the function of 5-HT_(7Ar).展开更多
A halophilic bacterium,named Halomonas sp.NEC-1 was isolated from the Nyer Co Salt Lake on the Xizang Plateau,SW China.The strain exhibited a broad pH tolerance range of 5-11,distinguishing it from Halomonas alkaliphi...A halophilic bacterium,named Halomonas sp.NEC-1 was isolated from the Nyer Co Salt Lake on the Xizang Plateau,SW China.The strain exhibited a broad pH tolerance range of 5-11,distinguishing it from Halomonas alkaliphila despite a 99% genetic similarity.Optimal growth conditions,determined through orthogonal experiments,were found to be 37℃,100-g/L salinity,and an initial pH of 6,resulting in a maximum OD_(600) of 7.98±0.06.Halomonas sp.NEC-1 produced 545.43±25.10 mg/L of ectoine under optimal conditions of 75-g/L salinity,40-g/L sodium glutamate,and an initial pH of 6.This production increased to 1388.81±3.69 mg/L after five rounds of hypo-osmotic shocks.During the shocks,ectoine productivity remained stable at approximately 16.29±0.04 to 17.28±0.48 mg/(L·h),representing a 43.40%-52.11% increase compared to the rate without any shock(11.36±1.05 mg/(L·h)).Additionally,the expression of the ectABC gene cluster,related to ectoine synthesis,significantly increased following the shocks,enhancing ectoine production.The ectoine extract demonstrated notable protective effects on Escherichia coli and plasmid DNA.After 10 min of exposure at 60℃,the colony count of E.coli treated with ectoine extract increased by 342% compared to treatment with distilled water.Furthermore,the ectoine extract protected plasmid DNA from 2,2′-Azobis(2-methylpropionamidine)dihydrochloride-induced damage.This study highlights Halomonas sp.NEC-1 is a promising strain for ectoine production and underscores the potential of microbial resources in salt lakes from Xizang region.展开更多
Microplastics pollution and seawater temperature rise have been the major environmental issues,threatening the survival and biodiversity of marine organisms.This study evaluated the combined effect of temperature and ...Microplastics pollution and seawater temperature rise have been the major environmental issues,threatening the survival and biodiversity of marine organisms.This study evaluated the combined effect of temperature and polystyrene microplastics(MP)on Artemia,a filter-feeding crustacean that is widely used for environmental toxicology studies.Brine shrimp Artemia franciscana were exposed to three MP concentrations(0,0.2,and 2.0 mg/L)and three temperatures(22,26,and 30℃)for 14 d.In general,higher MP concentration and temperature led to a decreased survival rate and growth.Two-way ANOVA analysis indicated that the survival rate of Artemia was significantly impacted by both MP concentration and temperature(P<0.05),but there was no significant interaction between two factors(P>0.05).Growth of Artemia was significantly impacted by temperature(P<0.05),and with a significant interaction between two factors(P<0.05).Furthermore,the enzymatic activity,intestinal histological analyses,and immune gene expression were determined for Artemia reared at 30℃ with three MP concentrations(0,0.2,and 2.0 mg/L).The results showed that 2.0-mg/L MP resulted in reduced Artemia intestinal microvilli and exfoliated epithelia cells,significantly increased acid phosphatase(ACP)activity(P<0.05)and immunerelated gene ADRA1 B and CREB3 expression,revealing that higher MP concentration could induce oxidative and immunological stress on Artemia at 30℃.Overall,our study suggests that MP and temperature have combined adverse effect on Artemia,especially at relatively high temperature and polystyrene MP concentration.These findings are important to understand the potential ecological risks posed by these two factors on the organisms in marine environment.展开更多
Deltamethrin(DEL),a commonly used pyrethroid pesticide,results in higher reactive oxygen species(ROS)levels in aquatic animals,which consequently unbalance the redox state.Phlorizin(PHL)is a flavonoid and a natural pr...Deltamethrin(DEL),a commonly used pyrethroid pesticide,results in higher reactive oxygen species(ROS)levels in aquatic animals,which consequently unbalance the redox state.Phlorizin(PHL)is a flavonoid and a natural product promising to prevent or reduce pesticide-induced oxidative stress.Artemia is a micro-crustacean widely used in marine hatcheries and an experimental aquatic organism for environmental toxicology research.This research aimed to evaluate the toxicity of DEL on Artemia and the antioxidative effect of PHL against the toxicity.Results show that 0.08-mg/mL PHL exerted its antioxidative effects on hatching percentage of the cysts in 24-h incubation and on body length and survival rate of Artemia in 12-d culture.After 12-d culture,12-,24-,and 36-h DEL exposure showed significant drops in SOD,CAT,and GSH-Px enzyme activities,and significant increases in ROS and malondialdehyde(MDA)levels in Artemia(P<0.05).On the contrary,0.08-mg/mL PHL application improved the enzyme activities and decreased the ROS and MDA levels(P<0.05).Moreover,0.08-mg/mL PHL significantly increased mRNA expression levels of Cu/Zn SOD,CAT,GST,HO-1,NQO1,and Nrf2,and decreased mRNA expression level of Keap1 in the DEL-exposed Artemia(P<0.05).Therefore,DEL is toxic to Artemia,while PHL alleviates DEL-induced oxidative damage by possibly regulating the Nrf2signaling pathway.This study provided a theoretical basis for PHL to reduce pesticide-induced toxicity in aquatic animals.展开更多
Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were invest...Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were investigated in this study using dietary archaeal carotenoids supplementation.For four weeks,shrimp were given diets containing 0 mg/kg(Ctrl)and 55.98 mg/kg(Car)archaeal carotenoids.Dietary archaeal carotenoids significantly enhanced the astaxanthin content in shrimp muscles and carapaces,as well as the superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activity(P<0.05).The malonaldehyde(MDA)content in Car group significantly decreased(P<0.05).The transcriptome analysis was conducted to determine the molecular processes in response to archaeal carotenoids supplementation.A total of 1536 differentially expressed genes(DEGs)were detected,including 538 upregulated DEGs and 998 downregulated DEGs.GO functional enrichment analysis between Ctrl and Car indicated that 26 GO terms including extracellular region,metabolic process,and proteolysis were enriched.The KEGG pathway enrichment analysis revealed that the amino sugar and nucleotide sugar metabolism,cysteine and methionine metabolism,glycine serine and threonine metabolism,and amino acid biosynthesis were enriched.Archaeal carotenoids influenced the expression of several important genes involved in reactive oxygen species(ROS)generation,Nrf2 signaling,and antioxidant enzymes.Seven DEGs were chosen to confirm the RNA-Seq data using qRT-PCR.The genes and pathways discovered in this work assist to elucidate the molecular processes through which archaeal carotenoid enhances L.vannamei antioxidative system.展开更多
The prokaryotic cell storage compound ploy-β-hydroxybutyrate(PHB)has been considered as prebiotics that can be applied in aquaculture.In this paper,the dietary effect of a PHB-accumulating Halomonas strain(HM·PH...The prokaryotic cell storage compound ploy-β-hydroxybutyrate(PHB)has been considered as prebiotics that can be applied in aquaculture.In this paper,the dietary effect of a PHB-accumulating Halomonas strain(HM·PHB)identified from our previous work were studied in Artemia under gnotobiotic and xenic culture conditions,in comparison of Halomonas without PHB accumulation(HM)and microalgae Isochrysis(ISO)feeding.Under gnotobiotic condition,both HM·PHB and HM served as sole food supporting Artemia survival.Although both HM·PHB and HM feeding had no significant difference on Artemia survival percentage(P>0.05),HM·PHB significantly improved their resistance against Vibrio anguillarum challenge(P<0.05).Mass Artemia culture were further performed in xenic condition.Compared to ISO,HM·PHB feeding protected Artemia against V.anguillarum challenge(P<0.05),and HM·PHB and HM feeding resulted in increased T-AOC,pepsin,T-SOD and CAT activities(P<0.05).High throughput sequencing analysis showed that HM·PHB and HM feeding resulted in a lower Artemia gut microbial diversity(P<0.05),and modified the gut microbial community by remarkably reducing the Vibrio proportion.The outcome of the paper confirmed the beneficial effect of Halomonas-PHB in Artemia culture,which supports the use of Halomonas-PHB in the production of bio-secured live feed Artemia.展开更多
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
Brine shrimp(Artemia)has existed on Earth for 400 million years and has major ecological importance in hypersaline ecosystems.As a crucial live food in aquaculture,brine shrimp cysts have become one of the most import...Brine shrimp(Artemia)has existed on Earth for 400 million years and has major ecological importance in hypersaline ecosystems.As a crucial live food in aquaculture,brine shrimp cysts have become one of the most important aquatic products traded worldwide.However,our understanding of the biodiversity,prevalence and global connectedness of viruses in brine shrimp is still very limited.A total of 143 batches of brine shrimp(belonging to seven species)cysts were collected from six continents including 21 countries and more than 100 geographic locations worldwide during 1977–2019.In total,55 novel RNA viruses were identified,which could be assigned to 18 different viral families and related clades.Eleven viruses were dsRNA viruses,16 were+ssRNA viruses,and 28 were−ssRNA viruses.Phylogenetic analyses of the RNA-directed RNA polymerase(RdRp)showed that brine shrimp viruses were often grouped with viruses isolated from other invertebrates and fungi.Remarkably,most brine shrimp viruses were related to those from different hosts that might feed on brine shrimp or share the same ecological niche.A notable case was the novel brine shrimp noda-like virus 3,which shared 79.25%(RdRp)and 63.88%(capsid proteins)amino acid identity with covert mortality nodavirus(CMNV)that may cause losses in aquaculture.In addition,both virome composition and phylogenetic analyses revealed global connectedness in certain brine shrimp viruses,particularly among Asia and Northern America.This highlights the incredible species diversity of viruses in these ancient species and provides essential data for the prevalence of RNA viruses in the global aquaculture industry.More broadly,these findings provide novel insights into the previously unrecognized RNA virosphere in hypersaline ecosystems worldwide and demonstrate that human activity might have driven the global connectedness of brine shrimp viruses.展开更多
基金Supported by the Program of Sustainable Development and Protection of Artemia Resources in Yuncheng Salt Lake of China(No.YHYJ-2023005)。
文摘Microplastics(MPs)are one of the most concerning pollutants that affects the health and growth of aquatic organisms.We characterized the MPs dispersion in the milli-Q water and seawater,and evaluated the effects of MPs on the gut epithelial cells of brine shrimp using three sizes of polystyrene(PS)microbeads(0.05,0.5,and 5μm,respectively).Results show that microbeads evenly dispersed in milli-Q water,but exhibited aggregation tendency in seawater associating with the particle size.Apart from a reduced survival rate,we observed the structure changes in the gut epithelium that the smaller size of PS microbeads resulted in an increased reactive oxygen species(ROS)and higher apoptosis-related genes expression.Moreover,exposure to all size of PS microbeads led to increased green fluorescence of J-monomer,indicating the declined mitochondrial membrane potential.Therefore,exposure to PS microbeads led to significantly size-dependent toxicity on brine shrimp.Especially,0.05-μm PS microbeads were more toxic,leading to severe oxidative stress and activation of the p53-Bax-Bcl2 pathway,ultimately resulting in cellular apoptosis and gut damage.These findings are important to understand the mechanism of MPs toxicity and its potential ecological risks to marine aquatic animals.
基金Supported by the Tianjin Key Laboratory of Marine Resources and Chemistry(Tianjin University of Science&Technology),Tianjin,China(No.202302)the National Natural Science Foundation of China(No.32460154)the China Postdoctoral Science Foundation(No.2023MD734227)。
文摘5-hydroxytryptamine(5-HT)is a biological monoamine neurotransmitter in the central nervous system and gonads of crustaceans to induce gonadal maturation.To better understand the effects of 5-HT and its receptors on reproductive development in Artemia,a 5-HT type 7 receptor gene(5-HT_(7Ar))was identified in parthenogenetic Artemia and characterized.Sequence analysis revealed that the open reading frame of 5-HT_(7Ar) encodes a 414-aa protein.5-HT_(7Ar) showed higher expression in both brain and ovary at early embryo stage,5-HT_(7Ar) could be detected during ovarian development and the highest expression was observed at early embryo stage.Silencing of the 5-HT_(7Ar) in Artemia at early embryo stage decreased significantly the expression level of 5-HT_(7Ar) gene and protein at late oocyte,early embryo,and late embryo stage.Moreover,silencing of the 5-HT_(7Ar) resulted in a decreased fecundity,which corresponds to abnormal oocytes during the embryo development.Artemia tended to produce nauplii after the silencing of 5-HT_(7Ar),indicating that 5-HT_(7Ar) may also involve in the determination of its reproduction mode.The findings of this study provide an insight into the regulation of reproductive development in Artemia and the function of 5-HT_(7Ar).
基金Supported by the Key Science and Technology Program of Xizang Autonomous Region(No.XZ202301ZY0012N)the Key Fisheries Resources and Environmental Survey Project in the Southwest Region(No.CJW2023034)the National Natural Science Foundation of China(No.42306106)。
文摘A halophilic bacterium,named Halomonas sp.NEC-1 was isolated from the Nyer Co Salt Lake on the Xizang Plateau,SW China.The strain exhibited a broad pH tolerance range of 5-11,distinguishing it from Halomonas alkaliphila despite a 99% genetic similarity.Optimal growth conditions,determined through orthogonal experiments,were found to be 37℃,100-g/L salinity,and an initial pH of 6,resulting in a maximum OD_(600) of 7.98±0.06.Halomonas sp.NEC-1 produced 545.43±25.10 mg/L of ectoine under optimal conditions of 75-g/L salinity,40-g/L sodium glutamate,and an initial pH of 6.This production increased to 1388.81±3.69 mg/L after five rounds of hypo-osmotic shocks.During the shocks,ectoine productivity remained stable at approximately 16.29±0.04 to 17.28±0.48 mg/(L·h),representing a 43.40%-52.11% increase compared to the rate without any shock(11.36±1.05 mg/(L·h)).Additionally,the expression of the ectABC gene cluster,related to ectoine synthesis,significantly increased following the shocks,enhancing ectoine production.The ectoine extract demonstrated notable protective effects on Escherichia coli and plasmid DNA.After 10 min of exposure at 60℃,the colony count of E.coli treated with ectoine extract increased by 342% compared to treatment with distilled water.Furthermore,the ectoine extract protected plasmid DNA from 2,2′-Azobis(2-methylpropionamidine)dihydrochloride-induced damage.This study highlights Halomonas sp.NEC-1 is a promising strain for ectoine production and underscores the potential of microbial resources in salt lakes from Xizang region.
基金Supported by the Science and Technology Project of Tianjin Municipal(No.17ZXZYNC00060)the Yangtze Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT_17R81)+1 种基金the National Science Foundation of Tianjin(No.18JCQNJC78500)the Foundation of Tianjin Key Laboratory of Marine Resources and Chemistry(Tianjin University of Science&Technology),China(No.201704)。
文摘Microplastics pollution and seawater temperature rise have been the major environmental issues,threatening the survival and biodiversity of marine organisms.This study evaluated the combined effect of temperature and polystyrene microplastics(MP)on Artemia,a filter-feeding crustacean that is widely used for environmental toxicology studies.Brine shrimp Artemia franciscana were exposed to three MP concentrations(0,0.2,and 2.0 mg/L)and three temperatures(22,26,and 30℃)for 14 d.In general,higher MP concentration and temperature led to a decreased survival rate and growth.Two-way ANOVA analysis indicated that the survival rate of Artemia was significantly impacted by both MP concentration and temperature(P<0.05),but there was no significant interaction between two factors(P>0.05).Growth of Artemia was significantly impacted by temperature(P<0.05),and with a significant interaction between two factors(P<0.05).Furthermore,the enzymatic activity,intestinal histological analyses,and immune gene expression were determined for Artemia reared at 30℃ with three MP concentrations(0,0.2,and 2.0 mg/L).The results showed that 2.0-mg/L MP resulted in reduced Artemia intestinal microvilli and exfoliated epithelia cells,significantly increased acid phosphatase(ACP)activity(P<0.05)and immunerelated gene ADRA1 B and CREB3 expression,revealing that higher MP concentration could induce oxidative and immunological stress on Artemia at 30℃.Overall,our study suggests that MP and temperature have combined adverse effect on Artemia,especially at relatively high temperature and polystyrene MP concentration.These findings are important to understand the potential ecological risks posed by these two factors on the organisms in marine environment.
基金the Key Laboratory of Marine Resource Chemistry and Food Technology(TUST)the Ministry of Education(No.EMTUST-21-08)the Guilin Science and Technology Project(No.20210225-4)。
文摘Deltamethrin(DEL),a commonly used pyrethroid pesticide,results in higher reactive oxygen species(ROS)levels in aquatic animals,which consequently unbalance the redox state.Phlorizin(PHL)is a flavonoid and a natural product promising to prevent or reduce pesticide-induced oxidative stress.Artemia is a micro-crustacean widely used in marine hatcheries and an experimental aquatic organism for environmental toxicology research.This research aimed to evaluate the toxicity of DEL on Artemia and the antioxidative effect of PHL against the toxicity.Results show that 0.08-mg/mL PHL exerted its antioxidative effects on hatching percentage of the cysts in 24-h incubation and on body length and survival rate of Artemia in 12-d culture.After 12-d culture,12-,24-,and 36-h DEL exposure showed significant drops in SOD,CAT,and GSH-Px enzyme activities,and significant increases in ROS and malondialdehyde(MDA)levels in Artemia(P<0.05).On the contrary,0.08-mg/mL PHL application improved the enzyme activities and decreased the ROS and MDA levels(P<0.05).Moreover,0.08-mg/mL PHL significantly increased mRNA expression levels of Cu/Zn SOD,CAT,GST,HO-1,NQO1,and Nrf2,and decreased mRNA expression level of Keap1 in the DEL-exposed Artemia(P<0.05).Therefore,DEL is toxic to Artemia,while PHL alleviates DEL-induced oxidative damage by possibly regulating the Nrf2signaling pathway.This study provided a theoretical basis for PHL to reduce pesticide-induced toxicity in aquatic animals.
基金Supported by the Project of China One-Belt-One-Road Foreign Expert Research Collaboration,Ministry of Science and Technology,China (No.DL2021002001L)the Open Project Program of State Key Laboratory of Food Nutrition and Safety,Tianjin University of Science&Technology (No.SKLFNS-KF-202205)。
文摘Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were investigated in this study using dietary archaeal carotenoids supplementation.For four weeks,shrimp were given diets containing 0 mg/kg(Ctrl)and 55.98 mg/kg(Car)archaeal carotenoids.Dietary archaeal carotenoids significantly enhanced the astaxanthin content in shrimp muscles and carapaces,as well as the superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activity(P<0.05).The malonaldehyde(MDA)content in Car group significantly decreased(P<0.05).The transcriptome analysis was conducted to determine the molecular processes in response to archaeal carotenoids supplementation.A total of 1536 differentially expressed genes(DEGs)were detected,including 538 upregulated DEGs and 998 downregulated DEGs.GO functional enrichment analysis between Ctrl and Car indicated that 26 GO terms including extracellular region,metabolic process,and proteolysis were enriched.The KEGG pathway enrichment analysis revealed that the amino sugar and nucleotide sugar metabolism,cysteine and methionine metabolism,glycine serine and threonine metabolism,and amino acid biosynthesis were enriched.Archaeal carotenoids influenced the expression of several important genes involved in reactive oxygen species(ROS)generation,Nrf2 signaling,and antioxidant enzymes.Seven DEGs were chosen to confirm the RNA-Seq data using qRT-PCR.The genes and pathways discovered in this work assist to elucidate the molecular processes through which archaeal carotenoid enhances L.vannamei antioxidative system.
基金Supported by the Tianjin Innovation Research Project for Postgraduate Students(No.2021 YJSS 047)。
文摘The prokaryotic cell storage compound ploy-β-hydroxybutyrate(PHB)has been considered as prebiotics that can be applied in aquaculture.In this paper,the dietary effect of a PHB-accumulating Halomonas strain(HM·PHB)identified from our previous work were studied in Artemia under gnotobiotic and xenic culture conditions,in comparison of Halomonas without PHB accumulation(HM)and microalgae Isochrysis(ISO)feeding.Under gnotobiotic condition,both HM·PHB and HM served as sole food supporting Artemia survival.Although both HM·PHB and HM feeding had no significant difference on Artemia survival percentage(P>0.05),HM·PHB significantly improved their resistance against Vibrio anguillarum challenge(P<0.05).Mass Artemia culture were further performed in xenic condition.Compared to ISO,HM·PHB feeding protected Artemia against V.anguillarum challenge(P<0.05),and HM·PHB and HM feeding resulted in increased T-AOC,pepsin,T-SOD and CAT activities(P<0.05).High throughput sequencing analysis showed that HM·PHB and HM feeding resulted in a lower Artemia gut microbial diversity(P<0.05),and modified the gut microbial community by remarkably reducing the Vibrio proportion.The outcome of the paper confirmed the beneficial effect of Halomonas-PHB in Artemia culture,which supports the use of Halomonas-PHB in the production of bio-secured live feed Artemia.
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 work was supported by the National Key Research and Development Program of China(2018YFD0900501)Central Public-interest Scientific Institution Basal Research Fund,YSFRI,CAFS(20603022022005)+6 种基金Shinan District Science and Technology Foundation(Qingdao)(2022-2-027-ZH)Central Public-interest Scientific Institution Basal Research Fund,CAFS(2020TD39)China Agriculture Research System(CARS-48)C.L.was supported by the Youth Innovation Team of Shandong Higher Education Institution(2021KJ064)the National Natural Science Foundation of China(32200004)W.S.was supported by the Academic Promotion Programme of Shandong First Medical University(2019QL006)E.C.H.was funded by a National Medical Health and Research Council(Australia)Investigator Grant(GNT2017197).
文摘Brine shrimp(Artemia)has existed on Earth for 400 million years and has major ecological importance in hypersaline ecosystems.As a crucial live food in aquaculture,brine shrimp cysts have become one of the most important aquatic products traded worldwide.However,our understanding of the biodiversity,prevalence and global connectedness of viruses in brine shrimp is still very limited.A total of 143 batches of brine shrimp(belonging to seven species)cysts were collected from six continents including 21 countries and more than 100 geographic locations worldwide during 1977–2019.In total,55 novel RNA viruses were identified,which could be assigned to 18 different viral families and related clades.Eleven viruses were dsRNA viruses,16 were+ssRNA viruses,and 28 were−ssRNA viruses.Phylogenetic analyses of the RNA-directed RNA polymerase(RdRp)showed that brine shrimp viruses were often grouped with viruses isolated from other invertebrates and fungi.Remarkably,most brine shrimp viruses were related to those from different hosts that might feed on brine shrimp or share the same ecological niche.A notable case was the novel brine shrimp noda-like virus 3,which shared 79.25%(RdRp)and 63.88%(capsid proteins)amino acid identity with covert mortality nodavirus(CMNV)that may cause losses in aquaculture.In addition,both virome composition and phylogenetic analyses revealed global connectedness in certain brine shrimp viruses,particularly among Asia and Northern America.This highlights the incredible species diversity of viruses in these ancient species and provides essential data for the prevalence of RNA viruses in the global aquaculture industry.More broadly,these findings provide novel insights into the previously unrecognized RNA virosphere in hypersaline ecosystems worldwide and demonstrate that human activity might have driven the global connectedness of brine shrimp viruses.
