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养殖大黄鱼冷藏过程中细菌菌相的变化 总被引：5，自引：0，他引：5
采用感官、挥发性盐基氮(TVBN)、菌落总数对大黄鱼(Pseudosciaena crocea)在0℃、5℃冷藏过程中的品质变化特征进行分析,并对细菌菌相进行定性和定量研究。结果表明,冷藏初期、高品质期和货架期终点菌落总数N(CFU/g)的对数值(lgN)分别为5.40±0.17、6.98±0.17、7.38±0.09,TVBN分别为(7.00±1.82)mg.100-1.g-1、(13.00±1.42)mg.100-1.g-1、(29.92±1.75)mg.100-1.g-1。冷藏初期分离获得211株菌株,84.8%是革兰氏阴性菌,出现少量革兰氏阳性菌(6.2%),优势菌群是肠杆菌科细菌(6.6%)、气单胞菌属(14.2%)、不动杆菌属(13.3%)、摩氏杆菌属(11.8%),并出现了一定比例的假单胞菌属、嗜麦芽窄食单胞菌和其他细菌。冷藏过程中细菌菌相逐渐变得单一,腐败希瓦氏菌上升趋势明显。高品质期时,0℃冷藏大黄鱼优势菌群为腐败希瓦氏菌(45.8%)和缺陷短波胞单胞菌(13.6%);5℃冷藏大黄鱼优势菌群为腐败希瓦氏菌(37.9%)和假单胞菌属(15.6%)。货架期终点时,0℃、5℃冷藏大黄鱼优势菌为腐败希瓦氏菌,比例分别为75.5%和59.6%。 相似文献
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植物源杀菌剂因其成分复杂、无污染、属性天然等特点,为水产养殖防治病原菌提供了新思路。本文以虎杖、千里光、黄柏、黄岑、苦参等为原材料,研制开发植物源杀菌剂,研究结果表明其对12种水产养殖常见病原菌均有较好的抑菌效果,对大肠杆菌、荧光假单胞菌的的最低抑菌浓度（MIC）为33μL／L,对金黄色葡萄球菌、痢疾志贺氏菌、温和气单胞菌的MIC为25μL／L,对肠炎沙门氏菌、单增李斯特氏菌的MIC为50μL／L,对拟态弧菌的MIC为100μL／L,对溶藻弧菌的MIC为250μL／L,对弗尼斯弧菌、副溶血弧菌的MIC为500μL／L,对创伤弧菌的MIC为1000μL／L。 相似文献
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采用富集培养、分离纯化等微生物学手段,从对虾养殖池的生物絮团中筛选出两株对氨氮具有高转化率的菌株.16S rRNA测序及系统发育分析结果表明,两株菌均属于盐单胞菌属,菌株2011072708与食物盐单胞菌Halomonas alimentaria有99％的同源性,而菌株2011072709与胜利盐单胞菌H.shengliensis有100％的同源性.比较研究了两株菌在不同温度、盐度、pH、碳氮比条件下对氨氮的转化率,菌株2011072708在温度37℃、盐度30～40、pH 8、碳氮比28的条件下对氨氮的转化率最高;菌株2011072709在温度27～42℃、盐度40～50、pH 6、碳氮比21的条件下对氨氮的转化率最高.研究结果表明,胜利盐单胞菌（2011072709）对温度、盐度、pH、碳氮比等各方面的适应性优于食物盐单胞菌（2011072708）,更适合在生物絮团技术中得到应用. 相似文献
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连续3年4个季节调查了青蛤携带的微生物系。结果表明,青蛤体内以细菌为主,其中革兰氏阴性杆菌达到70%以上。经鉴定,微球菌属、葡萄球菌属、微杆菌属、肠杆菌属、假单胞菌属、气单胞菌属、莫拉氏菌属、弧菌属是青蛤四季占主体的微生物,在活体青蛤中基本未检出霉菌和酵母等真菌。在不同季节,原料青蛤带菌量存在一定差异,对成品卫生指标产生影响。当青蛤菌落总数超过欧盟标准时,高温杀菌为128℃、5min,可使青蛤达到商业无菌条件;青蛤带菌量低于国家卫生标准时,其杀菌条件为120℃、5min。 相似文献
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为评价肉桂醛纳米乳对水产动物致病菌的抑菌效果,以吐温-80为表面活性剂、乙醇为助表面活性剂、乙酸乙酯为油相,加蒸馏水按比例配制成空白纳米乳,加入肉桂醛制备得肉桂醛纳米乳,并评价了肉桂醛纳米乳的部分特性;探究肉桂醛纳米乳对迟缓爱德华氏菌(Edwardsiella tarda)、嗜水气单胞菌(Aeromonas hydrophila)、温和气单胞菌(Aeromonas sobria)、鳗败血假单胞菌(Pseudomonas anguilliseptica)4种常见水产动物致病菌的抑菌效果。结果显示,肉桂醛纳米乳中吐温-80、乙醇、乙酸乙酯、蒸馏水和肉桂醛质量比为10∶5∶11∶73∶1,空白纳米乳对肉桂醛的最大载药量为20.11 mg/m L,肉桂醛纳米乳为水包油型淡黄色澄清透明液体,粒径5~20 nm,平均粒径10.74 nm;与同浓度肉桂醛溶液相比,肉桂醛纳米乳具有更强的抑菌活性,在最大载药量时,对嗜水气单胞菌、鳗败血假单胞菌、迟缓爱德华氏菌、温和气单胞菌的抑菌强度分别提高了65.56%、46.99%、41.94%、26.91%。肉桂醛纳米乳对嗜水气单胞菌、温和气单胞菌、鳗败血假单胞菌、迟缓爱德华氏菌的最小抑菌浓度(MIC)分别0.31、0.51、0.72、1.00 mg/m L。研究表明,肉桂醛纳米乳在水产养殖中具有潜在的应用价值。 相似文献
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为了给克氏原螯虾源异常嗜糖气单胞菌的防治提供科学依据,从湖北省某养殖场濒死的克氏原螯虾中分离得到1株优势菌,命名为X1。经生理生化试验分析,初步鉴定该菌为异常嗜糖气单胞菌(Aeromonas allosaccharophila)。进一步的序列分析显示,该菌的16S r DNA与异常嗜糖气单胞菌的16S r DNA一致性达90%,证明其为异常嗜糖气单胞菌。药敏试验结果表明,分离菌株X1对强力霉素、头孢噻肟、诺氟沙星、庆大霉素等敏感。通过动物回归试验,可分离到与自然发病的克氏原螯虾中相同的细菌,且患病症状一致。 相似文献
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养殖大黄鱼加工和冰藏过程中鲜度和细菌类型的变化 总被引：7，自引：5，他引：2
通过对养殖海水以及捕获、加工、流通和冰藏等整个供应链过程养殖大黄鱼的温度履历、感官、化学、微生物的品质监测,评估养殖海水、碎冰和加工过程中大黄鱼细菌卫生状况,分析其在整个过程鲜度和细菌相变化。结果表明,养殖海水和碎冰的菌落总数分别为4.99±0.41 lg cfu/g和3.90±0.32 lg cfu/g,大肠菌群数分别为30~450 MNP/100 g和低于30 MNP/100 g;新捕获养殖大黄鱼的菌落总数为3.82±0.38 lg cfu/g,假单胞菌数为3.13±0.58 lg cfu/g,嗜冷菌数为2.82±0.60 lg cfu/g,大肠菌群数为低于30 MPN/100 g;冰藏第18天时TVBN含量为28.62±0.51 mg/100 g,菌落总数、假单胞菌数、嗜冷菌数和大肠菌群数分别为6.24±0.06lg cfu/g、6.01±0.25 lg cfu/g、5.68±0.21 lg cfu/g和30 MPN/100 g。养殖海水和新捕获鱼中细菌种类繁多,革兰氏阴性菌分别占其总菌株数的64.9%和56.8%;革兰氏阳性菌分别占其总菌株数的27.0%和42.0%;优势菌群为黏性威克斯菌、腐败希瓦氏菌和假单胞菌属。加工结束后,假单胞菌(34.9%)、玫瑰小球菌(32.6%)和缺陷短波单胞菌(14.0%)成为主要菌群。冰藏第4天时仅分离出4种不同类型的细菌,腐败希瓦氏菌比例上升明显,冰藏第10天和第18天时,所占比例分别为63.5%和69.1%,是冷却链养殖大黄鱼产品的优势腐败菌。 相似文献
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正迟钝爱德华氏菌又称迟缓爱德华氏菌或缓慢爱德华氏菌,属于肠杆菌科的爱德华菌属(Edwardsiella)。它是该细菌家族中较早发现的成员之一。于1959年由日本的Sakazaki和Murata首先从蛇的肠道中分离得到。E.tarda是一种革兰氏阴性短杆菌,没有荚膜、芽孢,长度约2~3μm,直径约lμm,有周生鞭毛,能运动。该菌为兼性厌氧菌,生长温度范围为5~42℃,最适生长温为25~35℃;适宜pH范围为5.5~9.0,但pH7.2时生长较好;耐盐浓度范围为0~4%。同时,E.tarda可产H2S,能在胆硫乳琼脂(DHL)上形成黑色中心的特征菌落。 相似文献
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冷藏养殖大黄鱼细菌相组成和优势腐败菌鉴定 总被引：6，自引：1，他引：6
从菌落和细胞形态、生理生化特征、细胞脂肪酸组成及同源性分析等方面，结合使用Sensititre、BioFosun、MIDI细菌鉴定系统对0 ℃、5 ℃冷藏养殖大黄鱼货架期终点细菌相进行定性和定量研究，确定优势腐败菌。0 ℃、5 ℃冷藏优势菌为腐败希瓦氏菌，比例分别为75.5%、59.6%，在营养琼脂和胰酶解大豆胨琼脂培养基上菌落圆状隆起，边缘整齐，透明，无色至粉红色，革兰氏阴性杆菌，极生单鞭毛，大小为(0.6～0.9) μm×(1.5～3.3) μm，最适生长温度25～35 ℃、最适pH 7～9。菌株氧化酶和H2S呈阳性，能还原TMAO、液化明胶和Tween40，利用N乙酰基D葡萄糖胺等有机物。菌体主要脂肪酸为16∶1ω7c 、iso15∶0、17∶1ω8c、16∶0，比例分别为21.31 %、13.63%、9.82%、9.76%。菌株测试特征与细菌鉴定系统数据库比照，确定优势腐败菌为腐败希瓦氏菌。 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
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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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In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
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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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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
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Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
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
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Qin-Cheng Huang Di‐Gen Qin Bei‐Ping Tan Tao Du Yuan-Zhi Yang Qi-hui Yang Shu‐Yan Chi Xiao-hui Dong 《Aquaculture Research》2020,51(2):816-827
A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg. 相似文献
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William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献