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1.
《渔业科学进展》2018,(6)
为了有效保持南极磷虾(Euphausiasuperba)原料品质,实现其高质化利用,本研究选取冷冻南极磷虾作为研究对象,在实验室条件下以非蛋白氮(NPN)含量、三氯乙酸(TCA)可溶性蛋白含量与氨基酸态氮含量为指标,证实了南极磷虾NPN含量的变化可以表征蛋白自溶进程,且可以实现海上处理样品、运至陆地实验室后进行分析的目的。在此基础上,选取完整的及挤压破损的新鲜南极磷虾作为研究对象,以0～8h南极磷虾样品的NPN为指标,研究了南极磷虾起捕后蛋白自溶进程以及挤压破损对该过程的影响。结果显示,南极磷虾起捕死亡后的1h内,NPN无显著变化(P0.05),1 h后NPN迅速增加,挤压破损加速了南极磷虾的自溶进程,因此,目前的拖网作业方式有待改进。 相似文献
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食品添加剂对南极大磷虾蛋白自溶的影响 总被引：1，自引：1，他引：1
以氨基态氮、可溶性蛋白质含量和可溶性固形物含量为指标,研究了食品添加剂对南极大磷虾(Euphausia superba)蛋白自溶的影响。结果显示,氯化镁和柠檬酸对南极大磷虾蛋白的自溶有一定的促进作用,两者作用显著的添加量分别为2%和0.2%,结合可溶性蛋白质和可溶性固形物指标,促进作用最显著的为添加0.2%柠檬酸;葡萄糖和氯化钙对南极大磷虾蛋白的自溶影响不大;氯化钾、氯化钠、EDTA-2Na对南极大磷虾蛋白的自溶有一定的抑制作用,氯化钠和EDTA-2Na的抑制作用相近,但优于氯化钾,三者作用显著的添加量分别为2%、4%、0.05%,考虑到可溶性蛋白质含量,抑制作用最显著为添加0.05%EDTA-2Na。 相似文献
3.
南极大磷虾0、5和20℃贮藏中的品质变化 总被引：9，自引：1，他引：9
以感官、细菌总数、嗜冷菌数、TVB-N和TMA-N为指标,探讨了南极大磷虾在0、5和20℃贮藏中的品质变化,结合三氯乙酸可溶性氮含量和细菌菌相的变化对南极大磷虾腐败作用进行了分析。结果表明,南极大磷虾品质下降很快,0℃和5℃温度下15 h后品质不可接受,20℃温度下8 h后品质不可接受。0、5和20℃贮藏中南极大磷虾细菌总数、嗜冷菌数、TVB-N、TMA-N都有增加,三氯乙酸可溶性氮含量变化明显,细菌菌相变化不大,表明0、5和20℃贮藏中南极大磷虾自溶迅速,酶对其腐败起主要作用。 相似文献
4.
为了有效提取营养功效和附加值均更高的磷虾油,对南极磷虾(Euphausia superba)资源的综合开发利用提供参考,利用2013年7-8月和2013年12月-2014年5月在南乔治亚群岛和南设得兰群岛附近海域采集的南极磷虾样品,采用索氏抽提法,分别用无水乙醇、丙酮、石油醚、正己烷、乙酸乙酯、环己烷6种常见的有机溶剂作为提取试剂,对南极磷虾体内的脂肪进行提取,并确定最佳萃取溶剂.同时对南极磷虾脂肪、蛋白含量的季节变化及其与体长的关系进行了分析.结果显示,无水乙醇为南极磷虾脂肪提取的最佳溶剂.南乔治亚群岛海域7-8月南极磷虾脂肪含量和蛋白含量(干重)分别为(22.03±0.51)％和(64.52±0.16)％;其中,全长小于40 mm的磷虾个体,脂肪与蛋白含量均显著高于全长大于40 mm的个体(P＜0.05).从南极的初夏到秋末,南设得兰群岛海域的南极磷虾脂肪含量呈逐渐上升趋势,由12月的(19.83±0.04)％上升至翌年4月的最大值(30.584±0.02)％;5月则略有降低,为(28.66±0.03)％.与此相反,南极磷虾的蛋白含量则是12月最高、4月最低,分别为(66.75±0.14)％和(58.02±0.23)％;脂肪含量与蛋白含量呈显著负相关(P=0.005).研究结果对南极磷虾渔业及其生产安排具有直接的指导意义. 相似文献
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《渔业科学进展》2016,(3)
为了有效提取营养功效和附加值均更高的磷虾油,对南极磷虾(Euphausia superba)资源的综合开发利用提供参考,利用2013年7-8月和2013年12月-2014年5月在南乔治亚群岛和南设得兰群岛附近海域采集的南极磷虾样品,采用索氏抽提法,分别用无水乙醇、丙酮、石油醚、正己烷、乙酸乙酯、环己烷6种常见的有机溶剂作为提取试剂,对南极磷虾体内的脂肪进行提取,并确定最佳萃取溶剂。同时对南极磷虾脂肪、蛋白含量的季节变化及其与体长的关系进行了分析。结果显示,无水乙醇为南极磷虾脂肪提取的最佳溶剂。南乔治亚群岛海域7-8月南极磷虾脂肪含量和蛋白含量(干重)分别为(22.03±0.51)%和(64.52±0.16)%;其中,全长小于40 mm的磷虾个体,脂肪与蛋白含量均显著高于全长大于40 mm的个体(P0.05)。从南极的初夏到秋末,南设得兰群岛海域的南极磷虾脂肪含量呈逐渐上升趋势,由12月的(19.83±0.04)%上升至翌年4月的最大值(30.58±0.02)%;5月则略有降低,为(28.66±0.03)%。与此相反,南极磷虾的蛋白含量则是12月最高、4月最低,分别为(66.75±0.14)%和(58.02±0.23)%;脂肪含量与蛋白含量呈显著负相关(P=0.005)。研究结果对南极磷虾渔业及其生产安排具有直接的指导意义。 相似文献
6.
热处理是南极磷虾粉加工的一个重要环节,磷虾在热处理过程的特性变化对最终虾粉的得率和品质有较大的影响。为了研究南极磷虾热处理过程中不同中心温度下虾品质变化规律,采用常压水煮加热方式,设置热处理温度固定为100℃对南极磷虾进行热处理,以热处理损失率、固形物含量、脂肪含量、蛋白质组分含量、虾青素为品质评价指标,分别测定当中心温度在30℃~80℃区间范围、温度梯度5℃时南极磷虾的品质变化情况。结果表明:热处理达到不同中心温度对南极磷虾的品质有较大影响(P0.05)。随着中心温度的升高,磷虾的热处理损失率和固形物含量先逐渐增加后减少并趋于稳定,脂肪含量不断增加;水溶性蛋白和盐溶性蛋白的含量大致呈随着中心温度的上升而减少,仅在55℃~65℃略微升高后继续缓慢下降;虾青素含量在温度30℃~55℃时随温度升高缓慢下降,55℃之后下降速率加快;虾粉得率随温度升高呈不断下降趋势。综合考虑各项指标,认为南极磷虾常压水煮加热时中心温度应尽量控制在55℃~60℃。 相似文献
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8.
《渔业现代化》2018,(5)
为了提高南极磷虾的利用价值,以自主设计的南极磷虾脱壳机为研究对象,对其中的关键组件和滚轴长度、滚轴间隙、进料速度等工艺参数进行船载试验;对脱壳后的南极磷虾虾仁进行感官评定和出成率测定,确定了滚轴间隙、滚轴长度、进料速度和磷虾放置时间的最优组合。结果显示:在滚轴长度1. 0 m(A2)、滚轴间隙1. 0 mm(B2)、进料速度125 kg/h(C3)、放置时间15 min(D1)的条件下,各项试验指标皆达最佳;实际生产中采用A2B2C3D1工艺组合,南极磷虾虾仁的出成率达到24%。研究表明:该设备可以提高南极磷虾脱壳生产效率,提升南极磷虾高值化加工的自动化技术水平,从而推动南极磷虾产业化进程。 相似文献
9.
为探究南极磷虾(Eup Hausia superba)的自溶因素,将南极磷虾分别置于不同温度(30,40,50,60℃)、不同pH(6,7,8,9,10,11)、不同浓度NaCl溶液(0.2,0.4,0.6,0.8,1.0 mol/L)的条件下自溶3.5 h,提取粗酶液,以BApNA为底物,采用分光光度法检测粗酶液中胰蛋白酶活性的变化。结果显示:在温度为40℃、pH为8.0的条件下,胰蛋白酶活力达到最大值(0.076±0.002)U;在同等温度和pH条件下,随着Na~+浓度的升高,胰蛋白酶的活性逐渐被抑制,当Na~+浓度增大到1.0 mol/L时,胰蛋白酶活力为(0.004±0.547×10~(-4))U。试验结果表明,高温偏碱性的条件会加速南极磷虾的自溶,而高浓度的Na~+可以降低其自溶速率。 相似文献
10.
为建立南极磷虾(Euphausia superba)蛋白肽纳滤脱盐工艺,以脱盐率和蛋白损失率为评价指标,通过单因素实验和正交实验对影响南极磷虾蛋白肽纳滤脱盐效果的主要因素(蛋白肽浓度、压力、循环次数)进行优化。结果显示,采用纳滤技术对南极磷虾蛋白肽进行脱盐处理的最佳工艺条件：蛋白肽浓度为3%、纳滤压力为1.2 MPa、循环次数3次,在该条件下,南极磷虾蛋白肽的脱盐率达到(86.35±2.11)%、蛋白损失率为(9.10±0.35)%。采用优化工艺获得的南极磷虾蛋白肽的盐分含量为(1.14±0.12)%,蛋白质含量为(92.73±2.29)%,相对分子质量主要分布于3000 Da以下,氨基酸组成合理且符合联合国粮农组织/世界卫生组织规定的标准。研究将为高品质南极磷虾蛋白肽产品开发提供技术支撑。 相似文献
11.
Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
15.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
16.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 
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下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
17.
Iciar Martinez Amaya Velasco Ricardo Pérez-Martín Eskil Forås Michiaki Yamashita Carmen G. Sotelo 《Journal Of Aquatic Food Product Technology》2013,22(4):289-297
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus. 相似文献
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There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future. 相似文献
19.
Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load 下载免费PDF全文
下载免费PDF全文 Franz Lahnsteiner 《Aquaculture Research》2017,48(7):3901-3909
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos. 相似文献
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The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated. 相似文献