本文以双壁碳纳米管(double-walled carbon nanotubes,DWCNTs)为基础材料,通过化学沉淀法制备了磁性双壁碳纳米管(magnetic double-walled carbon nanotubes,m-DWCNTs),研究了 pH 和吸附剂投加量对全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)的吸附影响.采用扫描电镜(SEM)、傅里叶红外光谱(FTIR)、X射线衍射(XRD)和VSM对吸附前后的m-DWCNTs进行了观察,并进行了吸附动力学模型和等温线模型拟合.结果表明,磁化后的双壁碳纳米管包覆了铁的氧化物,出现了Fe3O4的特征衍射峰,具有超顺磁性,饱和磁化强度为66.07 emu-g1.m-DWCNTs对PFOS的吸附更符合准二级动力学方程(R2＞0.95)和Langmuir等温吸附模型(R2＞0.95).随着m-DWCNTs投加量的增加,吸附量逐渐降低,去除率逐渐升高.吸附量随着pH值的增加而逐渐降低,其主要原因有可能是m-DWCNTs对PFOS的吸附产生了静电作用.本研究结果为后续纳米材料处理水中的PFOS提供了借鉴和参考.

Based on the detection data of the two farms in Fengxian District of Shanghai from 2014 to 2018 and in 2021,8 water quality indicators, including the water temperature（T）,dissolved oxygen（DO）,permanganate index(I Mn ),total phosphorus（TP）,total nitrogen（TN）,ammonia nitrogen（TAN）,nitrite nitrogen（NO - 2 -N） and nitrate nitrogen（NO - 3 -N） were chosen to establish a prediction model based on principal component analysis（PCA） and long short-term memory（LSTM）. Firstly, through principal component analysis which was used to reduce data feature extraction and dimension, I Mn and TAN were determined to be the water quality prediction indexes to build a LSTM model based on the PCA analysis, then the PCA-LSTM model was used to predict the water quality of different ponds; Finally, comparison was carried out with a single LSTM model to verify the strengths and weaknesses of both models. The results show that the PCA-LSTM model can be used to predict I Mn and TAN in Litopenaeus vannamei aquaculture ponds, and the prediction results are better than the single LSTM model.

为优化全氟辛烷磺酸(PFOS)的紫外光降解条件及探明其降解机理,研究了PFOS在暗反应(Dark)、暗反应/碘化钾体系(Dark/KI)、紫外(UV)、紫外/碘化钾体系(UV/KI)、真空紫外(VUV)及真空紫外/碘化钾体系(VUV/KI)6种反应条件下的降解效果;在VUV/KI体系下,以单因素分析法研究了PFOS初始浓度、pH、KI添加量对PFOS降解效果的影响;通过中间产物分析提出PFOS在紫外光下的降解机理与路径.结果表明:①在Dark、Dark/KI体系下,PFOS均不会降解;在UV、UV/KI、VUV体系下,PFOS降解率均低于30％;在VUV/KI体系下,初始浓度为200μg/L、KI添加量为2 mmol/L,PFOS的8 h降解率可达70％.②降低PFOS的初始浓度、提高pH、增加KI添加量均有助于PFOS的降解.③轨道阱液质联用仪共鉴定出全氟辛酸(PFOA)、全氟丁酸(PFBA)、五氟乙烷磺酸(PFEtS)、五氟丙酸甲酯(MPFA)、三氟乙酸甲酯(MTFA)和三氟乙酸(TFA)等6种中间产物,PFOS的降解过程包括脱磺酸基团以及脱碳碳键反应.研究显示,水合电子是PFOS紫外光降解过程中的主要活性因子,VUV/KI反应体系可有效去除PFOS,降解路径及降解机理的分析可为其他全氟化合物的紫外光降解提供参考.

以虾壳为原料,450℃氮气保护下热解生成虾壳生物炭(SSBC),并研究它对Pb(Ⅱ)和(或)Cd(Ⅱ)的吸附特性和吸附机理.结果表明:(1)SSBC属于低比表面积类生物炭,N质量分数高达11.31％.(2)各体系下SSBC对Pb(Ⅱ)和Cd(Ⅱ)的吸附过程均符合假二级动力学模型,以化学吸附(络合、配位和(或)沉淀等)为主.在二元体系中引入竞争组分后,Pb(Ⅱ)和Cd(Ⅱ)的吸附平衡所需时间减少、吸附量下降.(3)Langmuir模型能更好地拟合SSBC对各体系下Cd(Ⅱ)和单一体系下Pb(Ⅱ)的吸附过程,而SSBC对二元体系下Pb(Ⅱ)的吸附过程更符合Freundlich模型拟合的结果.(4)Pb(Ⅱ)和Cd(Ⅱ)在SSBC上的吸附是几种机制共同作用的结果,其中吸附Pb(Ⅱ)的主要机理为碳酸盐沉淀,吸附Cd(Ⅱ)的主要机理为金属-π电子配位反应.

为了解凡纳滨对虾养殖对池塘后生浮游动物群落结构的影响,于2021年5月上旬至10月上旬在上海市奉贤区某养殖场及其外河道进行了 16次调查,分析了后生浮游动物的物种组成及优势种、密度、生物量和生物多样性.共鉴定出后生浮游动物33种(轮虫23种、枝角类6种、桡足类4种),优势种6种(轮虫4种、枝角类1种、桡足类1种),其中针簇多肢轮虫(Polyarthra trigla)和广布中剑水蚤(Mesocyclops leuckarti)为养殖塘和外河道共同优势种.Jaccard相似性分析表明,养殖塘与外河道后生浮游动物物种组成整体上处于中等相似水平.总体上养殖塘后生浮游动物密度、生物量、优势种数和多样性指数均高于外河道.养殖塘和外河道中Shannon-Wiener多样性指数 H'均值分别为1.56±0.48和1.55±0.34,表现为中度污染;Gleason-Margalef物种丰富度指数D均值分别为0.81±0.32和0.76±0.33,表现为重度污染;养殖塘总体处于中度富营养水平,外河道水体则处于轻度富营养水平.Pearson相关性分析表明,养殖塘后生浮游动物群落结构与水温(WT)、总氮(TN)、总磷(TP)、高锰酸盐指数(COD)和浮游植物中的隐藻门具有显著相关性,而外河道后生浮游动物群落分布与WT、溶解氧(DO)、叶绿素a(Chl.a)、COD、悬浮物(SS)和浮游植物中的隐藻门、裸藻门和甲藻门具有显著相关性.冗余分析(Redundancy analysis,RDA)表明,TP和COD是影响凡纳滨对虾养殖塘后生浮游动物群落结构的关键因子,而浮游植物中的隐藻属、DO、和TN则是影响外河道后生浮游动物群落的主要环境因子.研究结果表明凡纳滨对虾养殖池塘环境因子对后生浮游动物群落结构具有显著影响,且明显区别于外河道环境因子对后生浮游动物群落结构的影响,揭示了对虾养殖生产会显著改变天然水体中后生浮游动物群落结构,对凡纳滨对虾的生态养殖和水质调控具有重要意义.

建立了水中全氟辛烷磺酸(perfluoro-rooctane sulfonate,PFOS)的高效液相色谱-串联质谱法分析方法.用0.22 μm PP滤膜过滤水样,Poly-Sery HLB固相萃取柱对200 mL水样进行富集处理,以质量分数为10％的甲醇水溶液淋洗HLB柱以去除表面杂质,随后抽真空,再用4 mL纯甲醇溶液洗脱HLB柱.取洗脱液上机检测,以质量分数为0.1％的甲酸为流动相A,甲醇为流动相B,采用ACQMITY MPLC BEH C18色谱柱对洗脱液进行分离,负离子多反应监测模式检测,碎片离子m/z=80,内标法定量分析.在优化条件下,PFOS在0.01～50 μg/L范围内线性较好,相关系数r＞0.99,方法检出限为0.25 μg/L.方法加标回收实验添加浓度0.2、2.0和20 μg/L,PFOS加标回收率为82.1％～104.5％,相对标准偏差(RSD)为2.34％～5.64％.采集湖泊及养殖虾塘进出口水样进行测定,其PFOS含量均低于检出限,其中,湖水加标回收率为84.75％～112.2％,RSD＜5.62％,养殖塘水样加标回收率为81.7％～118.6％,RSD＜7.51％,实验所建方法可方便准确地检测水中PFOS含量.

采用静水毒性实验法和非靶向代谢组学法探讨全氟辛烷磺酸(perfluorooctae sulfonate,PFOS)对罗氏沼虾(Macrobrachium rosenbergii)幼虾的急性致死和代谢的影响,同时通过慢性毒性实验分析不同质量浓度(0.1 ng/mL、1ng/mL、5ng/mL)PFOS胁迫下幼虾鳃、肝胰腺和胃肠道中抗氧化酶活性的变化.结果表明,PFOS对罗氏沼虾幼虾的96 hLC50为(0.68±0.22)mg/L,安全质量浓度为0.068 mg/L.经20 ng/mL的PFOS胁迫24 h后,幼虾鳃中鉴定到具有显著差异的代谢化合物共30种、肝胰腺中19种、胃肠道中24种,这些代谢差异物主要涉及氨基酸代谢、脂肪酸代谢和磷脂类代谢等代谢通路.慢性毒性实验中,不同暴露时间下不同浓度的PFOS胁迫对幼虾各组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和酸性磷酸酶(ACP)活性的影响存在差异;随着暴露时间的延长,SOD、CAT和ACP活性受到抑制,MDA含量随着暴露时间的延长而增大.PFOS可造成幼虾鳃、肝胰腺和胃肠道组织发生氧化损伤,并对幼虾的生理代谢产生影响.本研究旨在为探究PFOS对水生生物的毒性效应提供基础数据和借鉴.

为探究凡纳滨对虾养殖过程中其肠道和养殖环境微生物群落的结构及变化,本实验采用Illumina MiSeq测序平台,基于16S rRNA基因的测序结果,对46和86 d虾龄的凡纳滨对虾肠道以及养殖水样、底泥中的微生物群落进行分析.结果显示,86 d时微生物Shannon-Wiener多样性指数显著高于46 d,水样中的Shannon-Wiener指数显著低于底泥和凡纳滨对虾肠道;有35个门、70个纲、152个目、274个科以及420个属在水样、底泥和虾肠道中均能检测到,其中虾肠道和底泥间共有菌类较水样中更多.微生物群落随养殖时间增加发生变化,46与86 d的差异性门类为放线菌门、绿菌门、丝状杆菌门、浮霉状菌门和TM6,相对丰度随时间增加而增高.水样、底泥和虾肠道中有相对固定的优势菌群,在水样、底泥和虾肠道中主要的门类均为变形菌门、拟杆菌门和放线菌门,优势纲类为α变形菌纲、β变形菌纲以及放线菌纲,除此以外,虾肠道与底泥共有的优势纲为δ变形菌纲、γ变形菌纲以及芽单胞菌纲;从目、科、属的分类水平上看,水样、底泥和虾肠道中菌类相对丰度各异,鲜有明显重叠的优势菌类,在水样、底泥和虾肠道中均为一种未分类的属占优势地位,水样中优势属为hgcI_clade,底泥和虾肠道中优势属为Ambiguous_taxa.研究结果进一步解释了虾肠道和环境微生物群落结构之间的相关性以及随虾龄增长呈现的差异性.

为了解凡纳滨对虾(Litopenaeus vannamei)养殖过程中水质与病害发生之间的关联性.对上海市奉贤区某虾类养殖合作社的池塘水质、养殖虾病原携带情况进行定期检测,结合其发病状况,使用主成分分析法(PCA)和正交偏最小二乘法(OPLS-DA),分析健康组、带病组、发病组同一时间段水质数据的差异性,并筛选出对各组差异贡献最大的水质因子.试验中,带病组和发病组的养殖虾均有检出虾虹彩病毒,分析表明:(1)发病组与健康组之间、发病组与带病组之间,水质有显著差异;而只要不发病,即便养殖虾携带病毒,该池塘水质与健康组之间并无显著区分.(2)水质因子与虾病发生的关联性程度为总氮>水温>总磷>溶解氧.(3)分塘等机械操作在一定程度上也会引起凡纳滨对虾的应激反应,诱发虾病的发生.(4)"带病&健康"组为大棚养殖,水温保持在30℃左右,即使凡纳滨对虾带有虾虹彩病毒,依然可以健康生长,但将其转移至较低水温条件下的露天池塘继续养殖时,则疾病暴发,出现死亡.养殖过程中应重视水温管理,注意水质变化,减少不必要的机械操作活动.

分析凡纳滨对虾(Litopenaeus vannamei)在大棚养殖(40、60、74、94 d)和露天养殖(40、60、80、95 d)模式下相近生长阶段肌肉中水解氨基酸和脂肪酸的组成和含量,并对其营养价值进行评价.结果 表明:(1)在大棚养殖和露天养殖模式下,凡纳滨对虾肌肉中粗蛋白、粗脂肪和粗灰分的含量在其相近生长阶段间无显著性差异.(2)大棚养殖模式下,凡纳滨对虾生长至40、60、74、94 d时的不饱和脂肪酸分别占脂肪酸总量的64.46％、60.97％、62.47％、63.16％;露天养殖模式下,凡纳滨对虾生长至40、60、80、95 d时的不饱和脂肪酸含量分别占脂肪酸总量的67.69％、64.74％、65.35％、65.63％.两种养殖模式下凡纳滨对虾肌肉均含丰富的不饱和脂肪酸,且大棚养殖模式下凡纳滨对虾在其相近生长阶段的多不饱和脂肪酸显著(P＜0.05)低于露天养殖.(3)大棚养殖和露天养殖模式下相近生长阶段凡纳滨对虾肌肉氨基酸组成基本一致,均包含17种氨基酸.大棚养殖模式下,凡纳滨对虾生长至40、60、80、95 d时必需氨基酸占总氨基酸的比值分别为29.36％、30.71％、33.28％、32.91％,必需氨基酸与非必需氨基酸比值分别为50.04％、55.63％、63.14％、60.56％;露天养殖模式下,凡纳滨对虾生长至40、60、80、95 d时必需氨基酸占总氨基酸的比值分别为34.70％、33.69％、32.93％、34.11％,必需氨基酸与非必需氨基酸比值分别为64.44％、63.72％、62.66％、66.76％,基本符合FAO/WHO理想模式,露天养殖的凡纳滨对虾氨基酸总量、必需氨基酸总量、鲜味氨基酸总量均显著高于大棚养殖.大棚养殖和露天养殖模式下凡纳滨对虾是一种高蛋白低脂肪,具有较高营养保健价值的虾类资源;露天养殖凡纳滨对虾肌肉营养品质总体优于大棚养殖的凡纳滨对虾.

近年来国家越来越重视语言文字工作,为了更好地开展此项工作,对上海市临港地区高校语言文字工作进行调研,设计高校语言文字工作一体化管理系统,对降低工作人员的工作强度、提高高校的管理水平具有较好的辅助效果.

通过气质联用仪和液质联用仪的非靶向检测,结合主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA)等方法,对日本沼虾肝胰腺进行代谢物分析,以研究在非致死剂量的亚硝酸盐或氨胁迫下,日本沼虾肝胰腺新陈代谢的变化.经亚硝酸盐(0.5 mg·L-1,以N计)胁迫2 d后,鉴定到具有显著差异的代谢化合物46个,涉及氨基酸代谢、脂肪酸代谢和甘油磷脂代谢等;pH=9.0时,氨(1.0 mg·L-1,以N计,即非离子氨氮为0.378 mg·L-1)胁迫后,鉴定出显著差异性代谢化合物52个,涉及三羧酸循环、氨基酸代谢和甘油磷脂等代谢通路.选择pH=9.0氨(1.0 mg·L-1)胁迫组对日本沼虾肝胰腺中的三羧酸循环进行定量验证实验,结果显示,日本沼虾肝胰腺中草酰乙酸含量与对照组相比在12 h显著升高,24 h和48 h后则与对照组无显著差异.α-酮戊二酸含量与对照组相比在12 h即有显著增加,24 h含量与对照组相比显著下降,48 h后与对照组相比无明显差异.推测pH=9.0时氨氮(1.0 mg·L-1)胁迫12 h即会对三羧酸循环产生影响.

In order to explore the mechanism of chronic toxicity of perfluorooctane sulfonate (PFOS) on livers of aquatic animals and to find potential markers related to chronic liver toxicity, a gas chromatography-mass spectrometry metabolomics method was used in this study, so as to study the effects of PFOS exposure on changes in liver endogenous metabolites and to discover metabolites that are of significant differences and their related pathways in Danio rerio. Four groups were set up including one control group and three experimental groups with PFOS concentration at 10, 100 and 250 μg·L-1, respectively. 20 pieces of Danio rerio were cultured in each group, and the experiment lasted for 40 days. The results showed that compared with the control group, four metabolites including taurine, phosphoric acid amide, β-D-glucose and oleic acid were identified from the liver of Danio rerio of the group with PFOS concentration at 10 μg·L-1 and four metabolic pathways including taurine and hypotaurine metabolism, sphingolipid metabolism, glycerophospholipid metabolism, and glycolysis or gluconeogenesis were involved. Five metabolites including taurine, β-D-glucose, palmitic acid, oleic acid and cholesterol, were identified from the liver of zebrafish of the group with PFOS concentration at 100 μg·L-1, and five metabolic pathways including primary bile acid biosynthesis, taurine and hypotaurine metabolism, steroid biosynthesis, steroid hormone biosynthesis and glycolysis or gluconeogenesis were involved. Four metabolites including taurine, β-D-glucose, lactic acid, glycerol-3-phosphate and phosphoacetamide, were identified from the liver of Danio rerio group with PFOS concentration at250 μg·L-1, and five metabolic pathways including taurine and hypotaurine metabolism, glycerophospholipid metabolism, glycerolipid metabolism, sphingolipid metabolism and glycolysis or gluconeogenesis were invloved. Based on the physiological functions of the identified metabolites and the analysis of their metabolic pathways, it was speculated that PFOS exerts toxic effects on Danio rerio liver mainly by interfering the metabolic pathways of taurine and hypotaurine, glycolysis or glucose production, and some lipid metabolism. Among them, the three metabolites including taurine, glucose and oleic acid can be used as potential markers for Danio rerio liver metabolism abnormalities induced by PFOS.

In order to remove microcystin (MC-LR) more easily, efficiently and eco-friendly, the sol-gel method was used to synthesize a sulfur doped TiO2 photocatalyst (S-TiO2).The catalyst was characterized using UV-VIS diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).Photocatalytic degradation of the cyanotoxin microcystin-LR (MC-LR, 0.1μg/mL) under visible was investigated to identify optimal conditions for S-TiO2 synthesis and for MC-LR degradation.Results show that the TiO2 crystal phase is anatase and the sulfur is fully oxidized, S (VI).The optimal conditions for S-TiO2 synthesis is a mole ratio (S:Ti) of 0.25 and calcining the product at 500℃ for 3 h.The S-TiO2 photocatalyst was stable and the degradation rate decreased only 3.98％after five cycles of recovery and reuse.At a catalyst dose of 0.1 g/L and a reaction time of 16 hat 3000 lux, the MC-LR (0.1μg/mL) was completely removed (100％ degraded) and the treated water complied with algal toxin limits set by the WHO and China, which is proved to be the most effective MC-LR degradation craft.

为研究凡纳滨对虾养殖过程中水质变化特征及其与浮游植物群落结构之间的相关性,本实验于2016年4月至9月在上海市奉贤区某养殖场开展凡纳滨对虾养殖池塘中水质及浮游植物的监测,分析浮游植物群落结构变化与水质因子的相关性.结果显示,凡纳滨对虾养殖池塘中共鉴定出113种浮游植物(包含20个未定种),分别属于7个门、59个属别,从种的数量上来看,绿藻门>硅藻门>蓝藻门>裸藻门>黄藻门>金藻门>甲藻门,18种(含3个未定种)优势种,第一批次共鉴定出10种(含1个未定种)优势种,第二批次共鉴定出14种(含2未定种)优势种,养殖初期优势种为硅藻门,之后是绿藻门,最终以蓝藻门为优势种.对浮游植物群落结构与水质因子进行典范对应分析可知,绿藻门主要受pH、无机氮的影响(包括总氨氮、亚硝酸盐氮、硝酸盐氮),蓝藻门主要受磷含量的影响(总磷和活性磷),硅藻门主要受温度的影响,因此在养殖过程中要格外关注温度、pH以及氮磷含量的变化.

To investigate the effects of cooking and storage on the volatile compounds of white shrimp (Litopenaeus vannamei), the electronic nose (E-nose) and headspace solid phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the volatile compounds in shrimp meat. The relative odor activity value (ROAV) and sensory evaluation methods were used to evaluate flavor change of shrimp meat. The results of E-nose showed that the effects of cooked and stored treatments were highly remarkable on the volatile compounds of white shrimp. According to GC-MS analysis, 50, 68, 63, 49 and 41 volatile compounds were detected in shrimp meat with raw shrimp, cooked shrimp, cooked shrimp cooled, cooked shrimp after placing at 4 ℃ overnight, and twice-cooked shrimp, respectively. After twice-cooking, the key flavor substances were slightly weakened and fresh aroma also decreased slightly in the shrimp meat. However, the first cooked had little effect on shrimp flavor. The raw shrimp meat were detected nonanal and decanal, which had a significant impact on flavor. Cooked shrimp were detected nonanal, decanal, tetradecanal and others. The twice-cooked shrimp meat were detected octadecanal, and butylated hydroxytoluene, which had a greater impact on flavor. The detected types and contents of volatile compounds were reduced in the cooked shrimp after storing, but the total difference was not significant. The results showed that the types and contents of volatile compounds of the twice-cooked shrimp could be significantly increased, and the key flavor kinds and contents ofL. vannamei were also significantly lower than those first cooked shrimp. The flavor difference of cooked shrimp was not significant at 4 ℃ for 12 h storage.

[目的]了解罗氏沼虾亲虾越冬时循环养殖系统对水质的调控效果,探明其中微生物群落的作用.[方法]采集循环养殖系统运行88 d后的越冬池池水、池中人工水草(普通纤维膜)以及外置式生物滤器中的纳米纤维膜等3种不同基质上的微生物,利用DNA抽提、PCR扩增和定量以及高通量MiSeq测序技术等对3种不同基质上的微生物进行16S rRNA基因序列V4-V5区的测定和分析,并根据测序得到的双端测序读长(Pair-end reads)进行质量控制和过滤,之后进行操作分类单元(OTU)聚类分析,并基于OTU对微生物群落的多样性指数和群落结构进行分析;每3-4 d对越冬池池水水质进行监测.[结果]养殖池塘的水质保持在良好的状态,其中氨氮和亚硝氮浓度控制在0.17+0.08 mg/L和0.28±0.15 mg/L;不同基质上的微生物组成和多样性都不相同.在3种基质上共检测并鉴定出细菌64种,隶属于9门64属,包括变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)、绿弯菌门(Chloroflexi)、厚壁菌门(Firmicutes)、浮霉菌门(Planctomycetes)、硝化螺旋菌门(Nitrospirae)、酸杆菌门(Acidobacteria)和绿菌门(Chlorobi).从属水平上对3种基质上的细菌进行分析,发现养殖池水中含量最高的为丛毛单菌科下的一个未分类类群(Comamonadaceae unclassified),其也是3种基质的共有优势类群;普通纤维膜上为Inhella,纳米纤维膜上则是小纺锤状菌属(Fusibacter).3种基质上细菌群落多样性顺序为:纳米纤维膜＞普通纤维膜＞养殖池水.通过对亲虾越冬养殖全过程的水质监测,发现越冬期间亲虾池水质始终保持在良好状态,并且在循环水系统开启约40 d后水质达到了相对稳定的状态.[结论]通过在育苗池中悬挂人工水草,配合内含纳米纤维膜的外置式生物滤器,可使罗氏沼虾越冬亲虾池保持良好的水质.随着新型材料科学的发展,开发出适用于水产养殖业的滤料很有必要.

White spot syndrome virus (WSSV) cause great harm in shrimp aquaculture. To understand the impact of viral infection on the shrimp metabolism, we monitored the culture farms of Litopenaeus vannamei and collected the samples on different stages of WSSV infection. The hepatopancreas of shrimp were separated, and then used gas chromatography mass spectrometry to detect the metabolites. Through the mass spectrometric analysis combined with multivariate data analysis, including PCA and OPLS models, metabolism of the shrimp was significantly changed by WSSV infection. The data indicated that in the early stage of WSSV infection, the glycolysis changed significantly, the contents of glucose and lactate increased distinctly. The metabolites of TCA cycle did not show up obviously regularity. The organism of fatty acids showed the same situation with glycolysis. At the early stage of infection, 14 amino acids metabolism were up-regulated, and glycine still increased at later stage of infection and the concentration was increased twice. The data of this study may provide some information to further research of viral disease mechanism.

In order to study the biodiversity of microbial community structure and explore the water quality purification mechanism of bio-filter in the recirculating aquaculture system for Litopenaeus vannamei,microorganism samples were collected from 5 different positions which were the outer and inner surfaces of the upper part of nano-membrane,the outer and inner surfaces of the lower part of the nano-membrane,and the collecting tray.Microbial diversity,functional microorganisms and purifying capacity among different samples were analyzed according to molecular biological methods and 16S rRNA gene pyro sequencing.The results showed that 10 phyla were identified in 5 different positions,in which Proteobacteria was the dominant group.Nitrospirae was detected in the nano-membrane (4.3％),while with low abundance in the collecting tray (0.33％).Ammonia oxidizing bacteria and nitrite oxidizing bacteria in nano-membrane were the primary microorganisms to remove nitrogen and the proportions were 1.70％ and 6.99％,respectively.There were 41 dominant species identified in total.Among which,Pedobacter was absolutely dominant,Parvularcula was the second dominant species,and both abundance ratios were above 10％.Nitrospira was the third dominant species,whose average abundance on membrane (4.31％) was significantly higher than that in the collecting tray (0.28％).Rich biodiversity of microorganism and stable microorganism ecosystem in the biological filter had a crucial role in buffering water quality.The analysis of effective biomass indicated that nitrification happened mostly in the upper part of the biological filter,and the nitrification effect was weakened in the lower part,while almost disappeared in the collecting tray.Therefore,in order to improve efficiency of nitrification,the hanging membrane density and length should be scientifically designed and rationally distributed.

以南美白对虾为对象,研究了多酚氧化酶(PPO)分离提取工艺及其生化特性.在单因素试验基础上,采用响应面试验优化了料液比、提取液pH值和浸提时间等因素提取南美白对虾PPO的工艺,并对PPO的生化性质进行分析.结果表明:液料比为2:1、提取液体系pH值为8.0、浸提时间为3h等条件下,提取的PPO具有最大酶活力为94.8 A/min·mL,所得回归模型显著(P＜0.0001),方程拟合性好(R2=0.9762),可用于预测南美白对虾中PPO的提取;PPO酶促反应动力学方程符合米氏方程,米氏常数Km为30.322 mmol/L,Vmax为0.281A/min.PPO性质研究将为南美白对虾黑变抑制提供理论指导.