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1.
The present work was carried out to evaluate the safety of shrimp(Solenocera crassicornis)treated with different concentrations of sodium metabisulfite(SMB)by soaking or spraying during frozen storage.Shrimps soaked in higher concentrations of SMB showed higher sensory scores,lower total color differences,and better anti-melanosis effects than shrimps in the control and other treatment groups throughout frozen storage(−18℃).Lower total volatile basic nitrogen and thiobarbituric acid reactive substances and higher salt soluble protein contents were detected in shrimp soaked with high doses of SMB compared with other samples.In addition,lower counts of total aerobic plates and psychrotrophic bacteria were observed in shrimp treated by soaking with higher doses of SMB than those in control shrimp and shrimp treated with other methods during frozen storage(−18℃).However,the SO2 content of 5%SMB-soaked samples exceeded the maximum allowable limit of 100mgkg−1.Overall,the use of 1.5%SMB soaking to treat shrimp results in good antioxidant and antimicrobial effects and,thus,may be suggested to preserve S.crassicornis under frozen conditions.The results of this study present important guidance on the use of SMB to maintain the quality of marine-trawling shrimp from manufacturing to consumption.  相似文献   

2.
Allergen extracts are widely used for allergy diagnosis and treatment. The application of shrimp extract is hampered dueto the low protein concentration and the inconsistent allergenicity. Extracting solutions are considered to be the primary limitingfactor of protein extraction from crustaceans. This study aimed to select an optimal solution for shrimp protein extraction by com-paring the allergenicity of different shrimp extracts. The effect of 7 existing or modified extracting solutions were evaluated, includ-ing the glycerol-NaC1 solution, the glycerol Cocaine＇s solution, the buffered saline solution, the Cocaine＇s solution, the Glucoseleaching solution, 1 mol L-1 KC1 solution, and 0.01 mol L-1 phosphate buffered saline solution with and without dithiothreitolor （DTT）.The quantitative （protein concentration） and qualitative parameters （SDS-PAGE protein patterns and immuno-reactivity） were deter-mined using the sodium dodecyl sulfate polyacrylamide gel electrophoresis, enzyme linked immunosorbent assay and immunoblottingassay. Results showed that the 1 molL-1 KC1 solution with DTT was optimal for shrimp protein extraction, which yielded high con-centrafion and allergenicity in the protein extract, including major and minor allergens. The 1 tool L-l KC1 solution with DDT is pro-posed for preparation of shrimp extract and associated allergy diagnosis, as well as potential applications for other crustaceans.  相似文献   

3.
Microbial-induced carbonate precipitation(MICP)is a relatively innovative and environmentally-friendly soil reinforcement technology,primarily used on sand,but its application in loess has rarely been studied.This paper explores the viability of the MICP technique for improving the engineering properties of typical loess.Sporosarcina pasteurii was used to trigger carbonate precipitation.Factors such as reaction temperature,p H of the media,and the inoculation ratio were adopted to determine the optimum conditions.Different concentrations of Sporosarcina pasteurii and cementation reagent were selected for combination to treat the loess samples with a selfdesigned vacuum test device.The unconfined compressive strength and calcium carbonate content of the treated samples were tested and Scanning Electron Microscopy(SEM)was carried out to evaluate the improving effect.The results showed that the optimum conditions are reaction temperature of 30℃,p H of the media of 9,a higher inoculation ratio can produce higher enzyme activity and monomer enzyme activity.The engineering properties of the MICP-treated loess are significantly improved.The obtained unconfined compressive strength increases nearly 4 times when the OD600 is 1.5 and cementation reagent concentration is 1 mol/L.The test results of calcium carbonate content are consistent with unconfined compressive strength.Finally,the microstructure of loess samples was quantitatively analyzed by Pore(Particle)and cracks analysis system(PCAS).It was showed that MICP has a great influence on the surface porosity,followed by the pore fractal dimension and the probability entropy,but has little influence on the pore average form factor.  相似文献   

4.
The industrial processing of shrimp produces massive quantities of solid waste that is a notable source of animal protein, chitin, carotenoids, and other bioactive compounds that are not appropriately utilized. In the present study, chitin and protein extraction from shrimp head with autolysis and fermentation using Bacillus licheniformis were investigated. The results showed that when shrimp heads were autolyzed with a natural pH at 50℃ for 4 h, the total amino acid nitrogen in the supernatant was 5.01 mg mL-1. Then, when a 50%(v/m) inoculum of the hydrolysate was incubated at 60℃ for 10 h, a deproteinization rate of 88.3% could be obtained. The fermented supernatant was processed into a dry protein powder, while the residues were demineralized by 10% citric acid for chitin. The recovered protein powder contained 5.5% moisture, 11.5% ash, and 66.7% protein, while the chitin contained 3.5% moisture, 2.1% ash, and 3.1% protein. In addition, amino acids, minerals, heavy metals, the degree of acetylation, microstructure, and Fourier-transform infrared(FT-IR) spectroscopy results were analyzed. Furthermore, the statistics of the large scale trial after treatment with 20 kg of shrimp heads were analyzed. Thus, this work made the shrimp waste utilization environmentally sound and valuable.  相似文献   

5.
Crustacean is one of the major allergic foods.It is of great significance to identify more crab allergens and research the detection methods for crab food anaphylaxis.In this study,IgE reactivity to three recombinant proteins from Portunus trituberculatus,including tropomyosin(rPtTM),myosin light chain(rPtMLC),and pancreatic lipase(rPtPL),were detected by enzyme-linked im-munosorbent assay(ELISA).The expressions of tropomyosin(TM)in various tissues of P.trituberculatus were detected by Western blot(WB).Furthermore,microplates were coated with rPtTM and the ELISA conditions were optimized.The cut-off value was deter-mined by the receiver operating characteristic(ROC)curve.Among 51 crab-allergic sera,21(41.2%)showed positive IgE to rPtTM.Other 70 crab-allergic sera more frequently recognized rPtPL(9/70;12.9%),followed by rPtMLC(1/70;1.4%).WB results showed that TM was mainly expressed in the muscle,followed by the heart and a small amount in gills and the testis.The optimal results showed that the coating condition of rPtTM was 50 ng per well with coating for 3 h at 37℃.The optimal blocking condition was 1.2%BSA with blocking for 3 h at 37℃,and the optimal dilution of the second antibody was 1:1500.The ROC curve showed that the ELISA reagent had high sensitivity(83.52%)and specificity(98.00%)when the cut-off value was 0.45.All results indicated that tropomyosin is the major allergen of P.trituberculatus,and myosin light chain and pancreatic lipase are the potential allergens.Addi-tionally,the ELISA reagent developed with the rPtTM was feasible for laboratory detection of crab anaphylaxis.  相似文献   

6.
The effects of different hydrolysis methods on peptidoglycan(PG) were assessed in terms of their impact on the innate immunity and disease resistance of Pacific white shrimp,Litopenaeus vannamei.PG derived from Bifidobacterium thermophilum was prepared in the laboratory and processed with lysozyme and protease under varying conditions to produce several different PG preparations.A standard shrimp feed was mixed with 0.05% PG preparations to produce a number of experimental diets for shrimp.The composition,concentration,and molecular weight ranges of the soluble PG were analyzed.Serum phenoloxidase and acid phosphatase activity in the shrimp were determined on Days 6-31 of the experiment.The protective activity of the PG preparations was evaluated by exposing shrimp to white spot syndrome virus(WSSV).Data on the composition of the PG preparations indicated that preparations hydrolyzed with lysozyme for 72 h had more low-molecular-weight PG than those treated for 24 h,and hydrolysis by protease enhanced efficiency of hydrolysis compared to lysozyme.SDS-PAGE showed changes in the molecular weight of the soluble PG produced by the different hydrolysis methods.Measurements of serum phenoloxidase and acid phosphatase activity levels in the shrimp indicated that the PG preparations processed with enzymes were superior to the preparation which had not undergone hydrolysis in enhancing the activity of the two serum enzymes.In addition,the preparation containing more low-molecular-weight PG enhanced the resistance of the shrimp to WSSV,whereas no increased resistance was observed for preparations containing less low-molecular-weight PG.These findings suggest that the immunity-enhancing activity of PG is related to its molecular weight and that increasing the quantity of low-molecular-weight PG can fortify the effect of immunity enhancement.  相似文献   

7.
Knowledge of oxygen consumption rates and asphyxiation points in fish is important to determine appropriate stocking and water quality management in aquaculture.The oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus were detected under laboratory conditions using an improved respirometer chamber.The results revealed that more accurate estimates can be obtained by adjusting the volume of the respirometer chamber,which may avoid system errors caused by either repeatedly adjusting fish density or selecting different equipment specifications.The oxygen consumption rate and asphyxiation point of C.mongolicus increased with increasing water temperature and decreasing fish size.Changes in the C.mongolicus oxygen consumption rate were divided into three stages at water temperatures of 11-33℃:(1) a low temperature oxygen consumption rate stage when water temperature was 11-19℃,(2) the optimum temperature oxygen consumption rate stage when water temperature was19-23℃,and(3) a high temperature oxygen consumption rate stage when water temperature was 27℃.The temperature quotients(Q_(10)) obtained suggested that C.mongolicus preferred a temperature range of19-23℃.At 19℃,C.mongolicus exhibited higher oxygen consumption rates during the day when the maximum values were observed at 10:00 and 14:00 than at night when the minimum occurred at 02:00.  相似文献   

8.
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9.
The swimming endurance of whiteleg shrimp （Litopenaeus vannamei, 87.66 mm±0.25 mm, 7.73 g±0.06 g） was exam-ined at various concentrations of dissolved oxygen （DO, 1.9, 3.8, 6.8 and 13.6mgL-1） in a swimming channel against one of the fiveflow velocities （vb v2, v3, v4 and vs）. Metabolite contents in the plasma, hepatopancreas and pleopods muscle of the shrimp werequantified before and after swimming fatigue. The results revealed that the swimming speed and DO concentration were significantfactors that affected the swimming endurance ofL. vannamei. The relationship between swimming endurance and swimming speedat various DO concentrations can be described by the power model （vtb= a）. The relationship between DO concentration （mgL-l） e 9000and the swimming ability index （SAI）, defined as SAI= ∫9000vdt （cm）, can be described as SAI=27.947DO0.137 （R2=0.9312）. Thelevel of DO concentration directly affected the physiology of shrimp, and exposure to low concentrations of DO led to the increasesin lactate and energetic substrate content in the shrimp. In responding to the low DO concentration at 1.9 mg L-1 and the swimmingstress, L. vannamei exhibited a mix of aerobic and anaerobic metabolism to satisfy the energetic demand, mainly characterized by theutilization of total protein and glycogen and the production of lactate and glucose. Fatigue from swimming led to severe loss ofplasma triglyceride at Vl, v2, and v3 with 1.9mgL-1DO, and at V1 with 3.8, 6.8 and 13.6mgL-1 DO, whereas the plasma glucose con-tent increased significantly at v3, v4 and v5 with 3.8 and 6.8mgL-1 DO, and at v5 with 13.6mgL-1 DO. The plasma total protein andhepatopancreas glycogen were highly depleted in shrimp by swimming fatigue at various DO concentrations, whereas the plasmalactate accumulated at high levels after swimming fatigue at different velocities. These results were of particular value to under-standing the locomotory ability of whiteleg shrimp and its physiological changes, further contributing to the improvement of captureand rearing technique.  相似文献   

10.
Measurements of three chlorofluorocarbons(CFCs) :trichlorofluoromethane (CFC-11),dichlorodifluoromethane (CFC-12) and trichlorotrifluoroethane (CFC-113), along with methyl chloroform (CH3CCl3) and carbon tetrachloride (CCl4) were made in water samples from Lake Washington,using Electron Capture-Gas Chromatography (EC-GC).The samples were collected in mid-autumn, a period when the lake‘‘‘‘‘‘‘‘s upper layer undergoes rapid cooling,At the time of sam-pling,a strong vertical temperature gradient was present in the lake,with surface temperatures of -14℃,and near bottom(50 meters) temperatures of -8℃ ,The concentrations of dissolved CFC-12 and CFC-11 increased with depht ,as expected from the higher solubilities of these gases at lower temperatures ,Atmospheric measurements made at the sampling site at the time of the cruise ,showed that CFC-11 and CFC-12 saturations in the near surface samples were 100% and 106%,respectively,For the deepest sample (52 meters)CFC-11 and CFC-12 saturations were 102% and 126%,Because the surface layer of the lake respondes to changes in atmospheric CFCs on a time scale of several weeks ,the highere than equilibrium concentrations of CFC-12 observed at the time of sampling may reflect earlier episodes of elevated levels of atmospheric CFC-12 in this urban area.High concentrations of dissolved CFCs in runoff or industrial effluent might also lead to elevated CFC levels in the lake. The cold ,deep water of Lake Wahington is realtively isolated from the effects of surface gas exchange except during winter ,and the supersaturations observed in the deep layer may reflect pe-riods of elevated atmospheric CFC-12 levels from the previous winter season.These results were compared to summertime profiles of CFC-11 and CFC-12 made in 1994.  相似文献   

11.
Pen a 1 is a major shrimp allergen that induces an allergy. The aim of this study is to assess the effect of simulated gastrointestinal fluids on the allergenicity of Pen a 1. Purified Pen a 1 from shrimp (Penaeus vannamei) was subjected to digestion in SGF (simulated gastric fluid) and SIF (simulated intestinal fluid) for a set time. The allergenicity of digestive Pen a 1 was analyzed by immunoblotting and Ci-ELISA, using pool sera from patients with shrimp specific IgE. The results showed that Pen a 1 exhibited a decrease in allergenicity with increasing digestion time in the SGF and SIF. However, Pen a l exhibited strong resistance to digestive fluids, and all yielded fragments (33 kD, 23 kD, and 14 kD) showed allergic activity. Therefore, anti-digestion may be an important factor for Pen a 1 to induce an allergy.  相似文献   

12.
Allergen extracts are widely used for allergy diagnosis and treatment. The application of shrimp extract is hampered due to the low protein concentration and the inconsistent allergenicity. Extracting solutions are considered to be the primary limiting factor of protein extraction from crustaceans. This study aimed to select an optimal solution for shrimp protein extraction by comparing the allergenicity of different shrimp extracts. The effect of 7 existing or modified extracting solutions were evaluated, including the glycerol-NaCl solution, the glycerol Cocaine's solution, the buffered saline solution, the Cocaine's solution, the Glucose leaching solution, 1 mol L-1 KCl solution, and 0.01 mol L-1 phosphate buffered saline solution with and without dithiothreitolor(DTT). The quantitative(protein concentration) and qualitative parameters(SDS-PAGE protein patterns and immuno-reactivity) were determined using the sodium dodecyl sulfate polyacrylamide gel electrophoresis, enzyme linked immunosorbent assay and immunoblotting assay. Results showed that the 1 mol L-1 KCl solution with DTT was optimal for shrimp protein extraction, which yielded high concentration and allergenicity in the protein extract, including major and minor allergens. The 1 mol L-1 KCl solution with DDT is proposed for preparation of shrimp extract and associated allergy diagnosis, as well as potential applications for other crustaceans.  相似文献   

13.
The heat budget of a melt pond surface and the solar radiation allocation at the melt pond are studied using the 2010 Chinese National Arctic Research Expedition data collected in the central Arctic. Temperature at a melt pond surface is proportional to the air temperature above it. However, the linear relationship between the two varies, depending on whether the air temperature is higher or lower than 0℃. The melt pond surface temperature is strongly influenced by the air temperature when the latter is lower than 0℃. Both net longwave radiation and turbulent heat flux can cause energy loss in a melt pond, but the loss by the latter is larger than that by the former. The turbulent heat flux is more than twice the net longwave radiation when the air temperature is lower than 0℃. More than 50% of the radiation energy entering the pond surface is absorbed by pond water. Very thin ice sheet on the pond surface(black ice) appears when the air temperature is lower than 0℃; on the other hand, only a small percentage(5.5%) of net longwave in the solar radiation is absorbed by such a thin ice sheet.  相似文献   

14.
Over the past few years, harmful algal blooms (HABs), such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors (temperature, salinity, light, and pH) on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels: temperature (15, 20, 25, and 30°C), salinity (10, 20, 30, and 40), light (20, 100, 200 and 400 μmol/(m2?s)), and pH (5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments (temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH). Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature (15°C), low salinity (10), high-intensity light (400 μmol/(m2?s)), and high pH (10) treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments: 15°C and salinity of 40, 25°C and pH 10, 25°C with medium- to high-intensity light at 200–400 μmol/(m 2 ?s), 400 μmol/(m2?s) and salinity of 10, 400 μmol/(m2?s) and pH 10, and pH 10 with a salinity of 40.  相似文献   

15.
The acute toxicity of five phenolic compounds each to 15 d old Artemia sinica was determined in this study. The brine shrimp A. sinica was hatched from the encysted dry eggs(Bohai Bay Brand) produced by Dongying Ocean Artemia Co., Ltd., China at 27℃± 1℃ in pre-filtered(through pores of 0.45 μm in diameter) and autoclaved seawater(salinity 31, pH 7.5–8.0) in a cilindroconical glass beaker(2000 mL in volume) under continuous illumination(provided by a side set 20 W fluorescent lamp) with slight aeration. Ten Artemia individuals from the same batch of the hatched were cultured in 10 mL toxicant solution prepared with seawater(salinity 31, pH 7.5–8.0) at room temperature(about 20℃) to determine 24 h, 48 h and 72 h medium lethal concentration(LC50) of 5 phenolic compounds each. It was found that the toxicity of n-heptylphenol was the highest followed by nonylphenol, t-butylphenol, 2,4-dichlorophenol and bisphenol A in order. The LC50 values of the 5 compounds were calculated with regression analysis. The real concentration(in μg- L1) of 5 phenolic compounds each in toxicant solutions was measured with GC/MS analysis. Significant loss of phenolic compounds caused by either adsorption or desorption was not found. The significant difference of LC50 values was found among the five compounds 3 exposure times each. The range between the highest no-observed-effect concentration(NOEC) and 100% death causing concentration of five phenolic compounds each was determined. The toxicity in term of 24 h LC50 value of n-HP was 9.10 times higher than that of BPA, 1.71 times higher than t-BP, 1.53 times higher than 2,4-DCP and 1.36 times higher than NP, respectively.  相似文献   

16.
ＳＴＡＴＩＳＴＩＣＡＬＡＮＡＬＹＳＩＳＯＦＴＥＭＰＥＲＡＴＵＲＥＳＯＮＢＯＴＨＴＨＥＵＰＰＥＲＡＮＤＬＯＷＥＲＢＯＵＮＤＡＲＩＥＳＯＦＳＵＢ－ＡＬＰＩＮＥＤＡＲＫＣＯＮＩＦＥＲＦＯＲＥＳＴＳＩＮＣＨＩＮＡＷａｎｇＪｉａｎ（王建）；ＸｕＸｉａｏｂｉｎ（...  相似文献   

17.
Compositional data on the sterol and alcohol fractions isolated from deep-sea marine sediments from the Okinawa Trough were obtained to determine the relative contribution from marine and terrestrial inputs. Following extraction, the sterol plus alcohol fraction was isolated by layer chromatography, derivatized with BSTFA and then analysed by capillary GC and GC—MS. A suite of C26−C29 stenols and stanols and C30−C32 keto—alcohols were identified in the sediments. The thermal stability of the compounds in these sediments was studied by heating portions of the surface sediment in glass tubes for 16 hours at temperatures from 50°C to 200°C. The C27 stanol/stenol ratio increased when temperatures went up to 175°C, but the distribution of C30−C32 Keto—alcohols remained unaffected. At 200°C most of the sterols and Keto—alcohols were destroyed. Supported by the National Natural Foundation of China.  相似文献   

18.
Randomly amplified polymorphic DNA (RAPD) technique was applied to assess the genetic variations and phylogenetic relationships in 4 species ofPorphyra. The samples were collected from the coast of Canada, Vietnam, Zhoushan, Fujian and Qingdao in China. Amplifications with 20 primers were carried out under predetermined optimal reaction conditions (samples were first heated at 94°C for 5 min. and followed by 45 cycles of 1 min at 94°C, 1 min at 36°C, and 2 min at 72°C, then held at 72°C for 10 min). The amplified products were scored as present (1) or absent (0) for each DNA sample and an index of genetic similarity (F) was calculated by using Nei & Li’s matching coefficient method (1979). The value of (1−F) was used to quantify the genetic distances between species and construct a phylogenetic tree. The relationship indicated by the UPGMA and NJ cluster analysis on the values of the genetic distance is in good overall agreement with classical taxonomy. The obvious differences between natural and cultivated population ofP. haitanensi suggest that variation or hybridization with other species occurred during the culture. Contribution No. 100 from the Experimental Marine Biology Laboratory, IOCAS. Contribution No. 3289 from the Institute of Oceanology, Chinese Academy of Sciences. The research supported by the Foundation of the Chinese Academy of Sciences.  相似文献   

19.
利用稳定同位素碳比率δ13C作为天然示踪物,对高位养殖池生态系统中人工饲料和天然饵料提供的能源物质对养殖凡纳滨对虾生长的贡献比率进行研究。结果表明:虾体的δ13C值受食物δ13C值的影响,由于其摄食饵料的δ13C值逐渐减小,虾体的δ13C值也逐渐降低,逐渐接近于最后人工饲料的δ13C值,试验虾体的δ13C值由养殖开始时的-19.52‰±0.09‰变为实验结束时的-21.74‰±0.17‰;对虾的食性在10d左右时发生转变,34d左右时人工饲料和浮游动物对虾体的能量贡献基本相同,养殖结束时对虾生长能量的97.29%±0.98%来源于人工饲料。  相似文献   

20.
EFFECTS OF LOW MOLECULAR WEIGHT CHITOSAN (LMC-1) ON SHRIMP PRESERVATION   总被引：1，自引：0，他引：1  
This study on the effects of low molecular weight chitosan (LMC- 1) and shrimp preserving agentssuch as phytic acid (PA), sodium bisulfite (SB), and crustacean preservative (CP) on the preservation ofshrimp (Trachypenaeus curvirostris) and the bacteriostasis of LMC-1 showed that: (1) Different LMC-1conontration has different bacteriostasis on E. coIi, B. subtilis and S. aureou: (2) LMC-1 and CP arebetter than PA and SB for preserving the freshness of shrimp stored at 4℃.  相似文献   

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