基于原位LAMP技术的牡蛎疱疹病毒(OsHV-1)易感宿主调查

牡蛎疱疹病毒(Ostreid herpesvirus 1, OsHV-1)给世界双壳贝类养殖业造成了严重的经济损失。10余种双壳贝类陆续被认定为易感宿主,仍有其他几种贝类仅有PCR核酸阳性数据,因确诊证据不足导致其易感性未得到充分评估。原位环介导等温核酸扩增(LAMP)检测技术相对传统原位杂交技术具有灵敏度高、方便快捷、可作为病原微生物感染证据的优点。为了在OsHV-1流行病学调查过程中实现病毒感染的快速检测和确诊,根据已报道的OsHV-1特异性LAMP检测引物,设计内引物,优化反应条件,建立了OsHV-1的原位LAMP检测方法。基于该方法对2019年以来采集的长牡蛎(Crassostrea gigas)、福建牡蛎(Crassostrea angulata)、栉孔扇贝(Chlamys farreri)、虾夷扇贝(Mizuhopecten yessoensis)、毛蚶(Scapharca subcrenata)和菲律宾蛤仔(Ruditapes philippinarum)样本进行检测。结果显示,毛蚶样本的OsHV-1原位LAMP检测结果呈阳性;其他几种贝类部分样本的实时定量PCR (qPCR)检测呈阳性,但原位LAMP检测呈阴性。对毛蚶样本的原位LAMP检测结果分析发现,病毒杂交信号主要分布在外套膜和肝胰腺等器官的结缔组织,推测感染的细胞为成纤维细胞和血淋巴细胞;在闭壳肌和斧足肌肉组织的肌细胞细胞核中也发现较多杂交信号。鳃丝内和周边偶现阳性信号,推测来自渗出的血淋巴细胞。基于原位LAMP技术的OsHV-1检测结果显示,毛蚶是OsHV-1的一种易感宿主,毛蚶结缔组织、肌肉组织和血淋巴细胞对该病毒有强亲嗜性。     

近江牡蛎等3种贝类的脂类成分分析

分析3种贝类的脂类成分,以期为贝类的高值化加工利用提供基础数据。采用氯仿甲醇法提取近江牡蛎、波纹巴菲蛤和马氏珠母贝中的脂质成分,分析脂质中的胆固醇和磷脂含量,采用液液萃取技术分离中性脂和极性脂,并用GC-MS分析其脂肪酸组成。研究结果表明,3种贝类的粗脂肪含量基本在1%左右;脂质成分中胆固醇含量在0.07~0.12 mg/g;脂质中磷脂含量在14%~34%,极性脂含量在27%~45%;脂质中EPA和DHA总含量在12%~22%,近江牡蛎和波纹巴菲蛤脂质中EPA含量高于DHA,而马氏珠母贝脂质中DHA含量高于EPA。     

乳山和广饶养殖贝类重金属含量分析及食用健康风险评估

采用单因子污染指数法分析了2015年上市出售前乳山海域养殖的太平洋牡蛎和广饶海域养殖的毛蚶、菲律宾蛤仔、文蛤、四角蛤等5种常见贝类中铜、铅、镉、铬、总汞等重金属的残留水平,并采用点估计法,通过计算贝类体内的重金属暴露风险商(HQ)评价食用上述5种贝类可能导致的健康风险。结果显示,不同种类的贝类中重金属含量差异较大,太平洋牡蛎中的铜和镉以及毛蚶中的铅含量较高,处于中污染水平,其他贝类中的重金属含量较低。然而暴露风险商(HQ)结果显示,成人和儿童仅在过量食用乳山养殖太平洋牡蛎时会存在镉的暴露健康风险,其中儿童受到的风险高于成年人,太平洋牡蛎中镉的摄食风险应该引起重视。本研究为建立适合中国的膳食暴露评估模型,制定合理的水产品中重金属污染物限量标准提供了参考。     

青岛地区贝类产品中诺如病毒的感染和流行初探

从2006年1月至2007年1月,在青岛市内3区5个主要水产品批发市场连续采集贝类样品,其中太平洋牡蛎Crassostreagi gas 208个、毛蚶Scapharca subcrenata 169个、杂色蛤Venerupis variegata 169个,采用RT—PCR方法检测诺如病毒（Novoviruses,NV）的感染,旨在为贝类食品的安全监控提供基础数据资料。研究结果表明,太平洋牡蛎和毛蚶样品中NV检出率分别为10．1％和5．3％,而杂色蛤未检出,NV流行的季节主要是11月至次年3月,感染部位主要分布于贝类的消化道。     

贝类中3种组织血型抗原ELISA检测方法的建立与分型

人类组织血型抗原(histo-blood group antigens,HBGAs)是诺如病毒(NoVs)的结合受体,本研究假设贝类中也存在类似的HBGAs并且特异性地富集NoVs,利用HBGAs单克隆抗体,建立贝类中3种HBGAs的ELISA检测方法,分析牡蛎(Crassostrea gigas)、缢蛏(Sinonovacula constricta)、菲律宾蛤仔(Ruditapes philippinarum)、紫贻贝(Mytilus galloprovincialis)、毛蚶(Scapharca subcrenata)、栉孔扇贝(Chlamys farreri)等6种双壳贝类中HBGAs的类型。结果显示,在上述6种贝类中都检测出A型抗原,其中菲律宾蛤仔的检出率为11.6%(9/77),紫贻贝的检出率为28.1%(16/57),缢蛏样品为72.3%(47/65),栉孔扇贝为84.6%(58/69),其余贝类检出率为100%;只有牡蛎样品检出H抗原,检出率为30.7%(28/91);在缢蛏和毛蚶样品中检测出B型抗原,检出率分别为76.9%(50/65)和77.8(56/72)。结果表明贝类中存在不止1种类型的HBGAs。     

我国贝类HACCP体系有效实施途径的探讨

我国生活着800余种海洋贝类,贝类产量名列世界第一。海水贝类养殖产量占海水养殖总产量的80%,是海水养殖业的一个重要组成部分。养殖品种有牡蛎、贻贝、扇贝、文蛤、青蛤、蛏、蚶、鲍等十多种,是我国水产品出口创汇的重要品种。双壳贝类,例如牡蛎、杂色蛤、毛蚶、文蛤,具有非选     

我国几种重要经济贝类中砷的含量及其形态特征转化规律

为了研究贝类中砷的含量及其形态特征,实验采用HPLC-ICP-MS联用技术结合体外全仿生消化模型分析了我国几种重要经济贝类中砷的形态特征及4种主要有毒砷形态的含量。结果显示,缢蛏中总砷含量最高,浓度为5.68 mg/kg,毛蚶4.83 mg/kg,栉孔扇贝、牡蛎和鲍鱼的含量为2.26～2.70 mg/kg,且三者之间无显著差异(P>0.05),菲律宾蛤仔和贻贝中总砷含量较低,分别为1.35和1.57 mg/kg。砷甜菜碱(AsB)是所有贝类水提液和胃肠全仿生消化液中砷的主要形态,尤其对于毛蚶,AsB是唯一的砷形态。栉孔扇贝、菲律宾蛤仔和缢蛏水提液中分别检测到0.025、0.008和0.300 mg/kg As3+,另外缢蛏水提液中还检测到0.115 mg/kgAs5+。除毛蚶和贻贝外,其余5种贝类的水提液中均检测到不同浓度的DMA,其中缢蛏中DMA浓度最高,为0.674 mg/kg。将贝类样品经过胃和肠消化液作用后,仅在缢蛏的肠消化液中检测出DMA,其余6种贝类中均未检出4种主要有毒砷形态。研究表明,贝类体内的砷形态及含量与在胃肠消化液作用后的砷形态及含量存在很大差异,尤其表现在4种主要有毒砷形态。     

皱纹盘鲍内脏脂质分析

对皱纹盘鲍内脏脂质进行了分析。采用Folch法提取内脏总脂,硅胶柱层析对中性脂及磷脂进行分离;TLC法对中性脂、磷脂不同组分进行分离与其主要组分的制备;10%硫酸—甲醇对样品进行甲酯化,通过气相色谱法对其进行脂肪酸分析比较。结果表明,皱纹盘鲍内脏中磷脂含量可达31.58%,不饱和脂肪酸在磷脂中含量显著高于中性脂中含量。磷脂中含有一定量的缩醛磷脂,磷酯酰乙醇胺(PE)中缩醛型磷脂含量可达50%。研究表明,皱纹盘鲍内脏中含有丰富的磷脂,多不饱和脂肪酸,并含有一定量的缩醛磷脂,具有较好的食用和药用价值,应得到充分利用。     

天津市售主要经济贝类中麻痹性贝类毒素污染现状及特征分析

使用液相色谱串联质谱法(LC-MS/MS)检测9种天津市售主要经济贝类中13种麻痹性贝类毒素(paralytic shellfish poisoning,PSP)的含量,分析PSP的污染现状和成分特征。结果显示,共计6个品种(紫贻贝、虾夷扇贝、牡蛎、毛蚶、脉红螺、菲律宾蛤仔)检出PSP。其中虾夷扇贝、紫贻贝、毛蚶3个品种的检出率较高且含量较高,检出率分别为66.7%、58.3%、58.3%。PSP中检出率较高的毒素包括N-磺酰胺甲酰基类毒素C1、C2和膝沟藻毒素GTX1、GTX2、GTX3,毒力占比主要以膝沟藻毒素GTX1-4为主,毛蚶蓄积STX毒素的能力强于其他贝类。全年的PSP含量季节变化为夏季最高,冬季最低。PSP主要存在于贝类的消化腺内,全年不同月份的PSP含量均在安全食用范围内。     

5种经济贝类在天津大港滩涂的养殖适应性研究

通过养殖试验,分析5种主要经济贝类的生长、存活及其养殖区的底质、生物饵料,探讨其在天津大港滩涂的养殖适应性。结果表明,5—8月份,贝类生长较慢,死亡率较高,9—11月份则相反;试验区夏季底质浮泥层较厚,海水中饵料生物缺乏,春秋季节则相反;该滩涂适于养殖长牡蛎、毛蚶,较适于养殖菲律宾蛤仔、青蛤,不适于养殖缢蛏。     

饲料脂肪水平对梭鱼脂肪沉积、脂肪代谢酶及抗氧化酶活性的影响

为了探讨饲料脂肪水平对梭鱼(Chelon haematocheilus)脂肪沉积、脂肪代谢酶及抗氧化酶活性的影响,选取360尾平均体质量为(5.4±0.2)g的梭鱼鱼种,随机分为6组,每组3个重复,每个重复20尾鱼,分别投喂脂肪含量为2.71%、5.79%、8.23%、11.85%、14.39%、16.91%的6组等氮饲料,饲养60 d,测定相应生物学指标及酶活。研究结果表明,随着脂肪水平的升高,肝体指数、脏体指数显著升高(P<0.05),肥满度8.23%组最大,其显著高于2.71%组(P<0.05);梭鱼全鱼、肝脂肪含量显著升高(P<0.05),14.39%组全鱼脂肪含量最高,16.91%组肝脂肪含量最高。饲料脂肪水平对肝脂肪代谢酶有显著影响(P<0.05),其中脂蛋白酯酶(LPL)、肝酯酶(HL)、总酯酶(GE)活性随着饲料脂肪水平的升高显著增高(P<0.05),16.91%组显著高于2.71%、5.79%、8.23%组(P<0.05);苹果酸脱氢酶活性呈显著下降趋势(P<0.05);血液中甘油三酯(TG)、总胆固醇(CHO)、游离脂肪酸(EFA)有升高趋势,但各组差异不显著(P>0.05);脂肪水平16.91%组高密度脂蛋白胆固醇(HDL)含量最高,显著高于脂肪水平2.71%的组(P<0.05);肝胰脏超氧化物歧化酶(SOD)活性随着饲料脂肪水平的升高呈先上升后下降的趋势,8.23%组活性最高,丙二醛(MDA)含量16.91%组显著高于其他5组(P<0.05)。结果显示,肝是梭鱼脂肪沉积的主要场所,肝脂肪沉积比肌肉更敏感,高脂肪饲料还使脂肪分解酶的活性增强,血脂含量增加;适宜的饲料脂肪水平可提高梭鱼的抗氧化能力,脂肪水平过高则会导致抗氧化能力下降。     

福建主要贝类养殖区养殖贝类体内重金属的含量与评价

通过1998年4月对福清、莆田、惠安、漳浦等4个贝类养殖区的褶牡蛎、缢蛏、花蛤等养殖贝类体内重金属含量的检测,结果表明:4个养殖区的养殖牡蛎体内Pb和Cd以及花蛤、缢蛏体内Cu、Pb、Cd、Zn的含量,都低于海洋生物污染评价标准,没有受到重金属的污染。     

六种淡水贝类耗氧率的初步研究

通过自制的流水密闭装置,测定了六种淡水贝类耗氧率,研究了起始溶解氧对贝类耗氧率的影响,结果表明:①六种淡水贝类耗氧率大小依次为:圆顶珠蚌、河蚬、扭蚌、背角无齿蚌、三角帆蚌和楔形丽蚌;②水中起始溶氧水平对贝类耗氧率有一定影响,起始溶氧水平与耗氧率呈线性正相关关系,随着起始溶解氧水平的降低,六种贝类耗氧率出现了不同程度的降低;③淡水贝类与其他滤食性鱼类相比具更强耐低氧能力,更适合作为水环境生态修复的工具种。     

The utilization of clam waste meal as a protein source for rainbow trout Salmo gairdneri

Solid waste recovered from clam processing wash water was evaluated for its utilization as a replacement protein for fish meal. Three diets, diets 1 and 2 formulated to simulate the Oregon Moist Pellet (OMP) and diet 3 (Rangen), were fed to rainbow trout (Salmo gairdneri) for eight weeks. The effects of the clam waste meal on fish growth, food conversion, carcass composition and whole body fatty acid content were determined. The clam waste diet supported maximum growth and food conversion. Carcass analysis of moisture, protein and lipid contents were similar among the moist feeds. The dietary levels of 20:5w3 + 22:6w3 and total polyunsaturated fatty acids (PUFAs) were significantly higher in the clam waste diet pellet.     

Effects of Dietary Lipids on the Growth Performance,Survival, and Digestive Enzymes of Juvenile Cuttlefish,Sepia lycidas

This study was conducted to determine the effects of dietary lipids on the growth performance, muscle composition, and enzyme activities of the stomach, intestines, and liver of Sepia lycidas juveniles. Fish oil and soybean lecithin were selected as lipid sources to formulate six experimental diets containing lipid levels of 3.68, 4.15, 6.62, 8.09, 9.56, and 11.03%. The feed efficiency first declined and then rose, with the lowest value obtained in individuals fed the 8.09% lipid content diet; the protein efficiency ratio significantly decreased with an increased lipid level. The highest crude protein content and lowest crude lipid content were simultaneously obtained in individuals fed the 9.56% lipid content diet. The activities of pepsase, trypsin, and intestine lipase initially increased before decreasing. The highest activities of protease, trypsin, and lipase were obtained in individuals fed the 9.56% lipid content diet, while the highest activity of amylase was obtained in individuals fed the 6.62% lipid content diet. Hepatic glutamate pyruvate transaminase and glutamic oxaloacetic transaminase initially increased and then held steady, with the highest activities simultaneously obtained in individuals fed the 9.56% lipid diet. Our results suggest that dietary lipids at a level of 9.56% could be the optimal lipid requirement for S. lycidas to grow and maintain normal metabolism.     

Effect of bleaching on lipid content and composition of Okinawan corals

Lipid contents and compositions of the bleached Okinawan corals were analyzed for the first time. Bleached corals collected at Sesoko Okinawa, Japan (26°38′N, 127°52′E), after the 1998 bleaching event showed decreased lipid content with a concomitant decline of wax in the lipid composition. The reductionin the lipid content of corals showed diversity depending on their colony morphology. On the whole, corals of massive morphology were relatively rich in lipid even after the bleaching event, and hence lesser reduction in the lipid content compared with the cases for those of branching morphology. Furthermore, there was a positive correlation between lipid content and zooxanthellae density in the bleached corals, suggesting again the importance of symbiont for the supply of lipid to the host cells, and hence for the survival of the bleaching event.     

Liver oil of pharaoh cuttlefish Sepia pharaonis Ehrenberg, 1831 as a lipid source in the feed of giant freshwater prawn, Macrobrachium rosenbergii (De Man 1879)

The efficacy of pharaoh cuttlefish ( Sepia pharaonis Ehrenberg, 1831) liver lipid in the feed for juveniles of giant freshwater prawn Macrobrachium rosenbergii (De Man 1879) was tested by feeding five experimental diets prepared using clam meat, groundnut oil cake, wheat bran, tapioca powder, vitamin–mineral mixture and cellulose powder as the major ingredients. The test diets T₁, T₂, T₃, T₄ and T₅, containing five levels (1, 2, 3, 4 and 5%, respectively) of lipid, extracted from the liver of pharaoh cuttlefish, were fed to 30-day-old prawn juveniles for 60 days, in triplicates and compared against a control. Analysis of variance of the growth parameters showed that the juveniles fed with T₂, containing 2% cuttlefish liver lipid with a total lipid content of 9.85% and lipid–carbohydrate ratio of 1 : 3.8, showed significantly better growth ( P  < 0.05) with the highest weight gain of 118%, greatest food conversion and protein utilization efficiency, and the highest body protein content, although the survival rates remained unaffected among treatments. Growth of the juveniles, however, declined at lipid levels >2%. Addition of cuttlefish liver lipid led to an increase of ω-3 and ω-6 fatty acids in T₂, the proportion of ω-6 being higher than the former. The crude lipid content of the body of test animals also increased with the increase in dietary lipid from 1.51% in T₁ to 3.27% in T₅. The present study indicates that cuttlefish liver lipid can be successfully used as a substitute for conventional lipid sources in rearing juveniles of giant freshwater prawn, an eco-friendly practice in recycling cuttlefish waste – a discarded fishery by-product.     

高铁肌红蛋白对腌腊鱼脂质氧化与挥发性风味的影响

为探究高铁肌红蛋白(MMb)对腌腊鱼品质的影响，实验在腌制草鱼肉中添加不同浓度MMb (0、 0.1、 0.2、0.4、0.8 mg/g)构建样品反应体系，基于羰基化合物、脂质含量、脂肪酸组成及挥发性风味物等指标，研究腌腊鱼传统加工中MMb促脂质氧化作用机制。结果显示，随着MMb添加浓度的升高，3种羰基化合物含量逐渐递增，且增幅存在“4-羟基己烯醛>4-羟基壬烯醛>丙二醛”的趋势。与对照组相比，添加0.8 mg/g MMb样品组总脂、甘油三酯和磷脂含量降幅最大(分别为18.95%、18.72%和31.83%)，而游离脂肪酸含量呈完全相反趋势(增幅为6.74%)。添加MMb浓度越高，鱼肉样品中多不饱和脂肪酸(PUFA)越容易发生氧化降解，亚油酸和花生四烯酸尤为显著(相对含量分别下降12.37%和16.27%)。本实验共检出6大类41种挥发性风味成分，确定了戊醛等13种气味活性物质，除癸醛外所有气味活性物质均与PUFA相对含量呈显著负相关，表明MMb介导的脂质光氧化反应可能是传统腌腊鱼香气的主要形成机制。     

Effect of Japanese catfish Silurus asotus lipid intake on the lipid components of plasma and liver in adult mice

SUMMARY: The effect of Japanese catfish Silurus asotus lipid intake on the lipid metabolism of male adult mice was determined by measuring the total cholesterol, triacylglycerol, phospholipid, and fatty acid content of plasma and liver. Mice were fed diets containing 5% lard, 5% Thai catfish oil, 5% Japanese catfish lipids, or 5% sardine lipids for 4 weeks. The arachidonic acid (20 : 4n-6) content was highest in the livers of mice fed the Japanese catfish lipid diet and docosahexaenoic acid (22 : 6n-3) content was higher in livers of the Japanese catfish lipid and sardine lipid diet groups than those of the lard and Thai catfish diet groups. However, no significant differences were observed in the 22 : 6n-3 levels in either plasma or liver between the Japanese catfish lipid and sardine lipid diet groups. Although the Japanese catfish lipid diet contains, by far, the highest cholesterol content (143 mg/100 g), there was no significant difference in the plasma cholesterol levels between the lard, Thai catfish oil and Japanese catfish lipid diet groups. However, the liver cholesterol levels of mice fed the Japanese catfish lipid diet were lower than those of mice fed the Thai catfish oil diet, and were similar to those of animals fed a sardine lipid diet. These results suggest that Japanese catfish lipids are suitable components of the diet for ingestion of 20 : 4n-6 and 22 : 6n-3, and for decreasing the cholesterol content of liver.