臭氧杀菌结合气调包装对缢蛏的保鲜效果

以缢蛏为研究对象,通过臭氧杀菌及不同气调包装处理,测定其在(0±0.5) ℃冷藏过程中的菌落总数、理化和感官等指标的变化,评价臭氧杀菌结合气调包装的保鲜效果。臭氧处理浓度为1 mg/L,包装条件分别为低氧气调包装(60% CO₂+30% N₂+10% O₂)、无氧气调包装(60% CO₂+40% N₂)、空气包装(对照)、低氧气调包装(60% CO₂+30% N₂+10% O₂)与臭氧处理复合、无氧气调包装(60% CO₂+40% N₂)与臭氧处理复合、臭氧处理包装。结果显示:0 ℃下缢蛏在空气包装下贮藏4 d和臭氧处理包装下贮藏8 d后菌落总数分别达到1.76×10⁷ cfu/g和1.14×10⁷ cfu/g,在有氧气调包装条件下和无氧气调包装调节下贮藏10 d后菌落总数分别达到1.87×10⁷ cfu/g和1.03×10⁷ cfu/g,超过规定的卫生标准;而有氧气调包装结合臭氧处理可使缢蛏的货架期达到12 d(9.33×10⁶ cfu/g),无氧气调包装结合臭氧处理可使缢蛏货架期延长至14 d(8.74×10⁶ cfu/g)以上。各处理组的TVB-N、K值、感官评分、pH变化也均与贮藏时间相关(P<0.05),并且气调包装结合臭氧处理组样品在冷藏期间的TVB-N、pH、K值和感官等指标均优于单独的气调包装或臭氧处理。相对于其它实验组,臭氧处理结合无氧气调包装组保鲜效果最好,样品在货架期末(14 d)TVB-N达到14.952 mgN/100 g,K值达到55%,感官评分达到5分,仍处于中等新鲜水平或可接受程度。总体结果表明,臭氧处理结合气调包装能有效延长冷藏缢蛏的货架期。     

缢蛏工厂化育苗技术的研究

利用现有的对虾育苗设施,进行缢蛏人工催产,浮游幼虫和稚贝培育,提供缢蛏养殖户所需苗种,获得成功。1997年出池稚贝平均密度76.26×10~4颗/m~2(壳长501～920μm),最高密度111.15×10~4颗/m~2(壳长501～811μm)     

缢蛏外套膜的组织学和组织化学研究

解剖壳长(53.24±2.23)mm缢蛏Sinonovacula constricta的外套膜组织,经H·E染色和特殊染色等组织学和组织化学方法研究了外套膜组织结构与细胞化学成分。组织学观察表明:外套膜由边缘膜和中央膜组成,无边缘膜突起;边缘膜由内外侧上皮、结缔组织、肌纤维及分布在其中的粘液细胞组成。组织化学研究显示:上皮细胞和分泌细胞内含物中含有丰富的糖类;外侧上皮和肌纤维蛋白质含量较高;在外侧上皮中检测到较强的碱性磷酸酶(ALP)活性。本研究结果可为解决缢蛏贝壳易破损、运输中大量死亡等问题提供参考。     

缢蛏鳃的光镜与扫描电镜研究

用光镜和扫描电镜观察了缢蛏鳃的组织学和表面结构。鳃丝有主鳃丝和普通鳃丝之分,鳃丝表面有前纤毛和侧纤毛,分别与食物的运送和呼吸水流的产生有关。普通鳃丝的扁平细胞为呼吸上皮。相邻鳃丝通过含有血管的丝间连接连系,相邻的鳃小瓣通过隔膜状的瓣间连接连系。两根主鳃丝之间的12~22根鳃丝由簇内连接连接成簇。     

冷海水保鲜在渔业运输船上韵应用

“沪渔冷1号”系200吨冷海水保鲜运输渔船。由上海船舶设计院，上海渔轮厂和上海市海洋渔业公司联合施工设计，上海渔轮厂建造，于1980年投入运营。在东、黄海配合灯诱围网作业中，渔获物保鲜效果良好。     

缢蛏多糖的提取及抗氧化作用研究

以新鲜缢蛏的碎肉为材料,加水配制成一定比例的匀浆,利用超声波提取法对缢蛏碎肉匀浆进行多糖的提取。利用蒽酮—硫酸法对多糖得率进行计算。将得到的多糖粗品通过DEAE离子交换层析及G-75凝胶层析进一步分离纯化。通过邻苯三酚自氧化体系和Fenton体系测定所得样品的抗氧化能力。结果表明:利用超声波提取多糖的提取率为19.93%。多糖粗品通过DEAE离子交换柱,得到2个峰,峰1对超氧阴离子的清除能率为43.89%,质量浓度为1 mg/ml时,对.OH清除率为57.80%。峰2对超氧阴离子的清除能率为57.80%,质量浓度为1 mg/ml时,对.OH清除率为77.83%。将DEAE峰2进行G-75凝胶层析得到2个峰,峰1对超氧阴离子的清除能率为83.08%,质量浓度为1 mg/ml时,对.OH清除率为94.76%。峰2对超氧阴离子的清除能率为74.41%,质量浓度为1 mg/ml时,对.OH清除率为52.41%。     

对虾池立体混养缢蛏技术的研究

缢蛏(Sinonouacula consticta)系为中潮带滩涂养殖贝类。采用对虾池立体混养缢蛏技术后,缢蛏不仅生长快、养殖周期短,而且肥温度高,产品质量好,深受消费者欢迎。这种新的养殖方法,实践证明是科学的、成功的,为对虾池综合利用水体开创了新途。     

南、北方缢蛏苗种在北方养殖的比较研究

缢蛏养殖在山东海阳市已有23年历史了,2001年海阳缢蛏曾获中国国际农业博览会金奖。但其养殖的缢蛏苗种一直是由外省提供的,在海阳市乃至山东省并没有缢蛏苗种的育苗单位,这是海阳缢蛏养殖的一大遗憾。     

酶制剂在水产品保鲜中的应用

水产品具有低脂肪,高蛋白的特点,是人们摄取蛋白质的重要食物来源。但是由于水产品的组织柔软,蛋白质和水分含量高,非常容易腐烂变质,因此,必须加大水产品的保鲜工作。目前水产品的保鲜方法主要有低温保鲜,化学保鲜,气调保鲜,辐照保鲜,酶法保鲜等。     

缢蛏肉的蛋白酶水解工艺研究

实验研究了用枯草杆菌中性蛋白酶水解缢蛏肉的工艺条件,通过单因素试验和正交实验,得出了最适水解工艺条件为加酶量2.4％,水解温度50℃.料水比1:3。pH值为中性,时间为6h.水解产物的水解率和总的氮收率分别为42.46％和83.04％。水解液经脱腥等处理后可用于复合调味料和营养口服液的生产。     

Effect of microalgae and temperature on absorption efficiency of razor clam (Sinonovacula constricta Lamark, 1818)

The razor clam (Sinonovacula constricta) is a bivalve species living in the lower to mid intertidal zones along the coasts of China, Japan and Korea. In this study, the effects of temperature, microalgae species and concentration on the absorption efficiency (AE) of cultured adult S Constricta fed with six species of microalgae, including Chlorella sp., Pavlova viridis, Nitzschia closterium f. minutissima, Platymonas subcordiformis, Nannochloropsis oculata and Isochrysis zhanjiangensis was examined. The clams were exposed to three different temperatures (15, 20 and 25°C) and five microalgae concentrations (0.16, 0.27, 0.37, 0.45 and 0.53 mg L^?1). The results indicated that under different temperatures, there is significant difference (P < 0.05) in AE and the efficiency peaks at the water temperature of 20°C. Under different microalgae concentrations, the absorption efficiencies were also significantly different (P < 0.05) and there was a negative correlation between AE and microalgae concentration. At different combinations of temperature and microalgae concentration, the absorption efficiencies of Chlorella sp. and N. oculata were lower than those of other microalgae. The interaction of temperature and microalgae concentration affected the AE significantly (P < 0.05).     

缢蛏ABC转运蛋白基因家族成员全基因组鉴定及表达模式分析

腺苷三磷酸结合盒转运蛋白(ATP binding cassette transporter,ABC transporter)家族是最古老的膜蛋白家族之一，广泛存在于原核生物和真核生物体内，利用ATP水解释放的能量对氨基酸、脂质、抗生素等物质进行跨膜运输，参与生物体内多种生理活动。目前，对软体动物ABC转运蛋白家族的鉴定，仅在虾夷扇贝(Patinopecten yessoensis)、栉孔扇贝(Chlamys farreri)和长牡蛎(Crassostrea gigas) 3种双壳类中有系统研究，对缢蛏(Sinonovacula constricta) ABC转运蛋白家族的鉴定和表达模式分析尚未见报道。利用缢蛏基因组和转录组数据，运用本地及NCBI在线BLAST程序、FGENESH+、SMART、Ex PASy、MEGA X、Mev 4.90和MapInspect等生物信息学分析工具，在全基因组水平系统地鉴定出52个缢蛏ABC转运蛋白，并对转运蛋白基因外显子数目、染色体定位等信息进行分析；通过系统进化分析，将缢蛏ABC转运蛋白家族分为8个亚家族，即ABCA～ABCH；通过比较分析不同物种...     

Vibrios in hatchery cultures of the razor clam,Solen marginatus (Pulteney)

Hatchery culture of the razor clam, Solen marginatus (Pulteney), has recently been developed in Galicia (NW Spain). However, recurrent episodes of mortalities of larval and post‐larval cultures have been recorded during the course of various studies. The disease signs were similar to those described for other bivalve species in outbreaks caused by bacteria of the genus Vibrio. In this article, we present the results of microbiological monitoring of two batches of razor clams with different survival rates. All fermentative isolates were identified as members of the Splendidus clade within the genus Vibrio. Some of these isolates, identified as Vibrio splendidus‐like, were clearly associated with the batch suffering mortalities, indicating their possible role as pathogens. Similar strains were found in the broodstock, suggesting vertical transmission of these bacteria. This is the first study of the microbiota associated with hatchery culture of S. marginatus, and the results will provide useful information for the optimization of a protocol for hatchery culture of this bivalve species.     

Culture possibilities of the razor clam Ensis arcuatus (Pharidae: Bivalvia)

This study investigated razor clam Ensis arcuatus culture from larval rearing to commercial size to assess it's aquaculture potential. Broodstock was spawned several times in hatchery facilities to demonstrate that larval availability is not a constraint for hatchery production. Larval culture lasted 20 days, showing an average survival of 14.35%. The razor clam seed reached a size of 28.5 mm at 4 months. Seed culture is feasible; however, it is constrained by the fact that razor clams need to be buried. Higher survival was observed when culturing razor clam seed with a substrate (82–83%), irrespective of the substrate grain size, while containers held without a substrate showed a significantly lower survival (56.5%). We showed that it is possible to rear E. arcuatus juveniles in bottles, with survival as high as 94–95% being achieved. The length increase of the hatchery‐produced E. arcuatus over 600 days was described by the equation Ln L=4.5+(?141.17/t), where L is length in mm and t is time in days. On‐growing showed adequate survival rates and it took 2–3 years to reach commercial size.     

Genetic variation of the razor clam Ensis siliqua (Jeffreys, 1875) along the European coast based on random amplified polymorphic DNA markers

Ensis siliqua is regarded as an increasingly valuable fishery resource with potential for commercial aquaculture in many European countries. The genetic variation of this razor clam was analysed by randomly amplified polymorphic DNA (RAPD) in six populations from Spain, Portugal and Ireland. Out of the 40 primers tested, five were chosen to assess genetic variation. A total of 61 RAPD loci were developed ranging in size from 400 to 2000 bp. The percentages of polymorphic loci, the allele effective number and the genetic diversity were comparable among populations, and demonstrated a high level of genetic variability. The values of Nei's genetic distance were small among the Spanish and Portuguese populations (0.051–0.065), and high between these and the Irish populations. Cluster and principal coordinate analyses supported these findings. A mantel test performed between geographic and genetic distance matrices showed a significant correlation (r=0.84, P<0.05), suggesting an isolation by distance process.     

饥饿再投喂对缢蛏消化酶活力和抗氧化能力的影响

在海水温度8～11℃,盐度20～22,pH7.4～7.9的条件下,将采自福建宁德的5种规格缢蛏(平均壳长0.7cm、1.4cm、2.0cm、4.0cm、6.0cm分别记为N1、N2、N3、N4、N5,其中N1、N2、N3为稚贝)饥饿6d后投喂单胞藻5d,以淀粉酶活力、纤维素酶活力、丙二醛含量和总抗氧化能力为指标,研究了饥饿再投喂期间不同规格缢蛏消化能力和抗氧化能力的变化过程,对缢蛏的补偿生长进行了初步探索。结果显示,缢蛏淀粉酶和纤维素酶活力有随个体增大而下降的趋势,总抗氧化能力随个体增大而升高。饥饿阶段:N1组消化酶活力迅速大幅下降,N2、N3、N4组不同程度升高后下降,N5组在饥饿期间无明显变化;丙二醛含量显著(除N3)降低(P<0.05),2～3d时降至最低,此后开始上升。恢复投喂后各组消化酶活力分别在1～4d升至显著高于饥饿前水平(P<0.05)。恢复投喂3d后N1、N4、N5组丙二醛含量降至显著小于饥饿前水平(P<0.05)。试验期间各规格缢蛏总抗氧化能力无显著变化(P>0.05)。试验结果表明饥饿再投喂对缢蛏抗氧化能力无显著影响但可提高其消化能力,说明可设置合理的饥饿再投喂模式使缢蛏发生补偿生长。     

Biochemical and fatty acid dynamics during larval development in the razor clam Ensis arcuatus (Bivalvia: Pharidae)

This article reports on the changes in gross biochemical and fatty acid composition of the razor clam Ensis arcuatus larvae throughout development. Protein was the largest component of dried larval tissues. The energy required for embryogenesis in E. arcuatus oocytes was obtained from stored proteins and carbohydrates, while total lipids increased significantly. Lipids and carbohydrates have an important role as energy contributors from day 1 to day 8. During larval development the strategy was to indistinctly store energy reserves (protein, lipid and carbohydrate) to surpass metamorphosis. During embryonic development there was a gain in fatty acids of neutral and polar lipids. A depletion of fatty acids in neutral lipids was observed from day 1 to day 8 in E. arcuatus larvae, mainly due to the decrease in 16:0 and EPA. NMID fatty acids were present in amounts similar to those of some PUFAs in polar lipids, especially 22:2NMID.     

缢蛏ScHsc70 cDNA的分子特性和表达分析

从缢蛏(Sinonovacula constricta Lamarck)cDNA文库中筛选出一条热休克蛋白70(Heat shock protein 70,HSP70)同源序列,采用EST扩增和5′RACE(rapid amplification of cDNA ends,RACE)扩增方法获得全长cDNA序列,共2 335 bp,包括76 bp的5′非翻译区和309 bp的3′非翻译区,以及1 950 bp的开放阅读框。阅读框共编码649个氨基酸,推算的分子量约为70.89 kD,理论等电点为5.28。氨基酸序列分析结果表明,该基因的氨基酸序列含有HSP70家族的3个签名序列,2个糖基化位点,1个ATP-GTP结合位点,且C末端具有GGXP四肽重复序列以及细胞质特异性调控基序EEVD。该基因是组成型HSC70(Heat shock cognate 70)亚家族基因成员,被命名为ScHsc70。基于氨基酸序列的双壳贝类聚类分析表明,缢蛏与南极帽贝(Laternula elliptica)、文蛤(Meretrix meretrix)的亲缘关系最近。荧光定量表达分析显示,ScHsc70 mRNA在缢蛏水管、鳃、斧足、外套膜、肝和性腺等组织中以不同水平存在,其中在外套膜中的表达量最低,而在水管和肝中的表达量最高。经副溶血弧菌(Vibrio parahaemolyticus)和副鳗弧菌(V.anguillarum)诱导后,ScHsc70 mRNA在缢蛏肝中的水平呈现先升高后下降的变化趋势,且分别在感染后的第20小时和第30小时达到最高。结果提示,缢蛏ScHsc70基因可能参与了对细菌感染的防御反应。     

青蛤生境及生长

青蛤生境及生长ＨＡＢＩＴＡＴＡＮＤＧＲＯＷＴＨＯＦＣＬＡＭ（ＣＹＣＬＩＮＡＳＩＮＥＮＳＩＳＧＭＥＬＩＮ）￥ＹｕＹｅｓｈａｏａｎｄＷａｎｇＨｕｉ（ＥａｓｔＣｈｉｎａＳｅａＦｉｓｈｅｒｉｅｓＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ，ＡＳＦ，Ｓｈａｎｇｈａｉ２０...