Influence of Ultrasonic Treatment on the Allergenic Properties of Shrimp （Penaeus vannamei ） Allergen

The present study was undertaken to determine whether high intensity ultrasound could reduce the allergic properties of shrimp allergens. Reducing the allergenic properties of these allergens will be beneficial to allergic individuals. Samples of shrimp protein extract and shrimp muscle were treated by high-intensity ultrasound with water bathing at 0 ℃ or 50 ℃ for different time periods. The treated and untreated samples were then analyzed by SDS-PAGE, Western blots and competitive inhibition ELISA （Ci-ELISA） to determine the shrimp allergenicity. The results show that high-intensity ultrasound has no effect on allergenicity when the extracts were treated at 0℃. However, a significant decrease was observed in the level of the major shrimp allergen, Pen a 1, when the samples were treated at 50 ℃. In the determination of allergenicity with CiELISA, a reduction in IgE binding was also observed.     

Comparative study on the allergenicity of different Litopenaeus vannamei extract solutions

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.     

A Study on the contribution of different food sources to shrimp growth in an intensive <Emphasis Type="Italic">Fenneropenaeus chinensis</Emphasis> pond

Stable isotope methods can be used to determine the food sources and prey items of aquatic organisms accurately and reliably. This study examined the relative contribution of artificial foods (the formulated feed and Artemia) and natural foods to shrimp growth in an intensive Fenneropenaeus chinensis pond by using carbon and nitrogen stable isotopes. The results showed that the nutrition utilization efficiency of the harvested shrimp was low, only 33.18% of feed nitrogen and 21.73% of feed carbon being converted to shrimp flesh. Our stable isotope results showed that the shrimp obtained nutrition for maximum growth from artificial foods, whose contribution was 93.5%, with the remaining attributed to the natural foods. However, there was 0.94 t harvested shrimp derived from natural foods (the rest of 13.56 t harvested shrimp derived from artificial foods) in 1ha intensive pond with a shrimp production of 14.50 t ha⁻¹. Therefore, unit area shrimp production can be increased by increasing the contribution proportion of natural foods in intensive shrimp farming.     

Influence of Probiotics on the Growth and Digestive Enzyme Activity of White Pacific Shrimp （Litopenaeus vannamel）

The influence of Bacillus probiotics on the digestive enzyme activity and the growth of Litopenaeus vannamei were de-termined in this study. The shrimp was treated with five percentages (1.5, 3.0, 4.5, 6.0 and 7.5) of probiotics (Bacillus spp.) supple-mented to the feed and cultured for 45d. The growth measured as the weight gain at the end of culturing was significantly (P<0.05) higher in probiotic-treated shrimps than that of the control (without receiving probiotics). Activities of protease and amylase, two digestive enzymes of the midgut gland and the intestine were significantly (P<0.05) higher in probiotic-treated shrimp than in the control.     

Structure and function of the digestive system of <Emphasis Type="Italic">solen grandis</Emphasis> dunker

Structure and function of the digestive system of a bivalve mollusc, Solen grandis, were studied using light microscopy and histochemical methods. The wall of digestive tube consists of four layers: the mucosal epithelium, connective tissue, muscular and fibrosa or serosa (only in the portion of rectum) from the inner to the outer. The ciliated columnar epithelial cells, dispersed by cup-shaped mucous cells, rest on a thin base membrane. There are abundant blood spaces in connective tissue layer. The digestive diverticula are composed of multi-branched duct and digestive tubules. The digestive tubules are lined with digestive and basophilic secretory cells, and surrounded by a layer of smooth muscle fibers and connective tissues. Activities of acid and alkaline phosphatases, esterase and lipase are detected in the digestive cells, and the epithelia of stomach and intestine, suggesting that these cells are capable of intracellular digesting of food materials and absorbing. Besides, acid phosphatase and esterase activities are present in the posterior portion of esophagus. Phagocytes are abundant in blood spaces and the lumens of stomach and intestine, containing brown granules derived from the engulfed food materials. The present work indicates that phagocytes play important roles in ingestion and digestion of food materials, which is supported as well by the activities of acid phosphatase, esterase and lipase detected in blood spaces.     

EFFECTS OF LOW MOLECULAR WEIGHT CHITOSAN (LMC-1) ON SHRIMP PRESERVATION

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℃.     

Effects of temperature, pH and NaC1 on protease activity in digestive tract of young turbot, Scophthalmus maximus

The protease activity in digestive tract of young turbot Scophthalmus maximum was studied, and the optimal pH, temperature and NaCl concentration were determined for different portions of the fish＇s internal organs. The optimal activity in the fish＇s stomach was at pH of 2.2, while that in the intestinal extracts was within the alkaline range from 9.5 to 10.0. In hepatopancreas, the optimal pH was in low alkalinity at 8.5. The optimal reaction temperature was above 40℃ in stomach, intestine and hepatopancreas. With increasing temperature, the pH value increased in stomach, while in the intestine, an opposite tendency was observed due to combined effect of pH and temperature. NaCl concentration showed inhibitory impact on protein digestion in hepatopancreas. The main protease for protein digestion in turbot seemed to be pepsin. Moreover, the maximum protease activity in different segments of intestine existed in the hindgut.     

Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop <Emphasis Type="Italic">Chlamys farreri</Emphasis>

Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment. Supported by the Technology Development Program of Shandong (No. 2008GG1005010) and the Program of Introducing Talents of Discipline of Universities (111 Project, No. B08049)     

Purification and characterization of lectin from humoral fluids of Charybdis feriatus

1 INTRODUCTION Lectins have been regarded as having a puta- tive role in non-self recognition in vertebrate and invertebrate immunities (Arason, 1996; Matsushita, 1996; Olafsen, 1996; Vasta et al., 1999; Wilson, et al., 1999; Marques and Barracco, 2000). …     

Three-dimensional fluorescence characteristics of dissolved organic matter produced by <Emphasis Type="Italic">Prorocentrum donghaiense</Emphasis> Lu

Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrum donghaiense at the exponential growth,stationary and decline stages into <0.45 μm filtrate,100 kDa-0.45 μm,10-100 kDa and 1-10 kDa retentate and <1 kDa ultrafiltrate fractions.The fluorescence properties of different molecular weights of dissolved organic matter(DOM) were measured by excitation-emission matrix spectra.Protein-like and humic-like fluorophores were observed in the DOM produced by P.donghai...     

A genetic linkage map of marine shrimp Penaeus (Fenneropenaeus) chinensis based on AFLP, SSR, and RAPD markers

The Chinese shrimp Penaeus (Fenneropaeneus) chinensis is an important species in marine fishery and aquaculture in China. A female Chinese shrimp Penaeus (Fenneropaeneus) chinensis was captured from west coast of the Korean peninsula and mated with a “Yellow Sea No. 1” male to produce the first filial generation (F₁) 100 F₂ full-sib progeny from brother-sister crosses between F₁ families was used for the mapping study. A genetic linkage map of the Chinese shrimp was constructed, based on 354 markers, including 300 amplified fragment length polymorphism (AFLP) markers, 42 microsatellite (SSR) markers, and 12 randomly amplified polymorphism (RAPD) markers. Forty-seven linkage groups (LGs) were identified. The total map length was 4 580.5 cM, with an average spacing of 11.3 cM, covering 75.8% of the estimated genome size. The construction of this genetic linkage map was part of a genetic breeding program. This linkage map will contribute to the discovery of genes and quantitative trait loci (QTLs) in Chinese shrimp.     

Effect of water temperature on digestive enzyme activity and gut mass in sea cucumber Apostichopus japonicus （Selenka）, with special reference to aestivation

The effect of water temperature on gut mass and digestive enzyme activity in sea cucumber Apostichopus japonicus, including relative gut mass (RGM), amylase, lipase, pepsin and trypsin activities were studied at temperatures of 7, 14, 21, and 28°C over a period of 40 days. Results show that RGM significantly decreased after 40 days at 21°C and markedly decreased over the whole experiment period at 28°C; however, no significant effect of duration was observed at 7 or 14°C. At 14°C, trypsin activity significantly decreased over 10 and 20 days, then increased; amylase and trypsin activity significantly decreased after 40 days at 28°C. However, no significant effect of duration was found on amylase, pepsin or trypsin activities in the other temperature treatment groups. At 28°C, lipase activity peaked in 20 days and then markedly decreased to a minimum at the end of the experiment. On the other hand, pepsin activity at 28°C continuously increased over the whole experimental period. Principle component analysis showed that sea cucumbers on day 40 in the 21°C group and in the previous 20 days in the 28°C group were in the prophase of aestivation. At 28°C, sea cucumbers aestivated at 30–40 days after the start of the experiment. It is concluded that the effect of temperature on the digestion of A. japonicus is comparatively weak within a specific range of water temperatures and aestivation behavior is accompanied by significant changes in RGM and digestive enzyme activities.     

Effect of co-culture of Chinese shrimp (<Emphasis Type="Italic">Fenneropenaeus chinensis</Emphasis>) and sea cucumber (<Emphasis Type="Italic">Apostichopus japonicus</Emphasis> Selenka) on pond environment

Monoculture of sea cucumber (pond S) and polyculture of shrimp with sea cucumber (pond SS) were established to evaluate the effect of shrimp on the environmental conditions of sea cucumber farming pond. Contributions of sediment organic matter (SOM2) resuspended from benthic sediment and the suspended particulate organic matter (SPOM) deposited from the water column to the precipitated organic matter (SOM1) collected with sediment traps were estimated with carbon stable isotope analysis. The results showed that the levels of SPOM and SOM2 in pond SS significantly decreased in comparison with those in pond S at the end of experiment (P < 0.05), indicating that co-culturing shrimp in sea cucumber farming pond could purify the farming water. Carbon stable isotope analysis showed that the proportion of SOM2 in SOM1 in pond SS (84.97% ± 0.38%) was significantly lower than that in pond S (95.20% ± 0.30%) (P < 0.05), suggesting that the resuspension of organic matter from benthic sediment into overlying water was reduced in polyculture pond. In contrast, the proportion of SPOM in SOM1 in pond SS (15.03% ± 0.38%) was significantly higher than that in pond S (4.80% ± 0.30%) (P < 0.05), indicating that the sedimentation of SPOM from water column was enhanced in pond SS owing to the biodeposition effect of shrimp.     

Species composition and gear characteristics of the <Emphasis Type="Italic">Macrobrachium</Emphasis> fishery of the Cross River Estuary,Nigeria

The Cross River Estuary, Nigeria, is an important shrimping area for artisanal fishermen of the coastal communities. The multi-species Macrobrachium fishery is exploited with three main gears, namely beach seine, push net and trap. Studies on species composition of this fishery recorded thirteen shrimp species, one swimming crab (Callinectes amnicola) and two fish species (Eleotris sp. and Pellonula leonensis). The shrimp species identified included Macrobrachium macrobrachion (83.39% and 55.69% by number and weight, respectively), M. vollenhovenii (9.66% and 37.18%), M. equidens (3.8% and 2.87%), juveniles-sub-adults of Penaeus notialis (1.11% and 1.3%), M. dux, M. felicinum, Palaemonetes africanus, Palaemon maculatus, Palaemon elegans, Desmocaris sp., Leander sp., Nematopalaemon hastatus and Alpheus pontederiae. While the selectivity index for trap was 0.25, beach seine and push net had a lower index of 0.063. The results present the first comprehensive and representative report for the Estuary shrimp fishery and will assist in the management of the biodiversity of this ecosystem.     

A Study on the Contribution of Different Food Sources to Shrimp Growth in an Intensive Fenneropenaeus chinensis Pond

Stable isotope methods can be used to determine the food sources and prey items of aquatic organisms accurately andreliably.This study examined the relative contribution of artificial foods (the formulated feed and Artemia) and natural foods toshrimp growth in an intensive Fenneropenaeus chinensis pond by using carbon and nitrogen stable isotopes.The results showed that the nutrition utilization efficiency of the harvested shrimp was low,only 33.18% of feed nitrogen and 21.73% of feed carbon beingconverted to shrimp flesh.Our stable isotope results showed that the shrimp obtained nutrition for maximum growth from artificialfoods,whose contribution was 93.5%,with the remaining attributed to the natural foods.However,there was 0.94 t harvested shrimpderived from natural foods (the rest of 13.56t harvested shrimp derived from artificial foods) in lha intensive pond with a shrimpproduction of 14.50 tha-1.Therefore,unit area shrimp production can be increased by increasing the contribution proportion of natu-ral foods in intensive shrimp farming.     

Vaccination in three different ways against vibriosis of <Emphasis Type="Italic">Seriola dumerili</Emphasis> caused by <Emphasis Type="Italic">Vibrio hollisae</Emphasis>

Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili （amberjack） suffering from vibriosis. Healthy S. dumeriIi were vaccinated by respective procedures of intramuscular injection, immersion, and orally administration. Results of the three different vaccinations were compared. Blood was drawn from the vaccinated fish every 7 days, and the antibody titers and lysozyme activities of the sera were determined. The antibody titer of injected fish was 1：40 at 7 d, and reached its peak of 1：320 at 28 d, while the fish vaccinated by immersion and orally administration exhibited weak antibody responses, the antibody titres of 〈1：10, 1：20, 1：160 were observed at 7 d, 14 d, 35 d respectively. Compared with the control, the vaccinated fish exhibited significantly higher lysozyme activities （P〈0.05）. Upon challenge with virulent strain, the relative percent survival （RPS） of injected, immersed and oral administrated fish were 75%, 45%, and 40% respectively, and the injected fish showed significantly higher RPS than immersed and oral administrated fish. The results suggested that vaccination of S. dumerili by the injection would be the best strategy to prevent the vibriosis in S. dumerili farm.     

Nitrogen Budget in Recirculating Aquaculture and Water Exchange Systems for Culturing <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>

In order to investigate the culture characteristics of two indoor intensive Litopenaeus vannamei farming modes, recirculating aquaculture system (RAS) and water exchange system (WES), this study was carried out to analyze the water quality and nitrogen budget including various forms of nitrogen, microorganism and chlorophyll-a. Nitrogen budget was calculated based on feed input, shrimp harvest, water quality and renewal rate, and collection of bottom mud. Input nitrogen retained in shrimp was 23.58% and 19.10% respectively for WES and RAS, and most of nitrogen waste retained in water and bottom mud. In addition, most of nitrogen in the water of WES was TAN (21.32%) and nitrite (15.30%), while in RAS was nitrate (25.97%), which means that more than 76% of ammonia and nitrite were removed. The effect of microalgae in RAS and WES was negligible. However, bacteria played a great role in the culture system considering the highest cultivable cultivable bacterial populations in RAS and WES were 1.03×10¹⁰ cfu mL^?1 and 2.92×10⁹ cfu mL^?1, respectively. Meanwhile the proportion of bacteria in nitrogen budget was 29.61% and 24.61% in RAS and WES, respectively. RAS and WES could realize shrimp high stocking culture with water consuming rate of 1.25 m³ per kg shrimp and 3.89 m³ per kg shrimp, and power consuming rates of 3.60 kw h per kg shrimp and 2.51 kw h per kg shrimp, respectively. This study revealed the aquatic environment and nitrogen budget of intensive shrimp farming in detail, which provided the scientific basis for improving the industrial shrimp farming.     

Isolation and identification of a bacterium from marine shrimp digestive tract: A new degrader of starch and protein

It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp (Litopenaeus vannamei) intestines by using multiple selective media.The selected isolate STE was identified on the basis of its morphological, physiological,and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus Pseudoalteromonas.This study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract.     

Hematological changes in white spot syndrome virus-infected shrimp, Fenneropenaeus chinensis (Osbeck)

The pathological changes of hemocytes in the haemolymph and hepatopancreas were examined in experimentally and naturally WSSV (white spot syndrome virus) infected Fenneropenaeus chinensis. The results showed that the pathological manifestations of hemocytes were similar among moribund shrimps infected via injection, feeding and by nature. Firstly, the total hemocyte counts (THCs) in WSSV-infected shrimp were significantly lower than those in healthy shrimp. Secondly, necrotic, broken and disintegrated cells were often observed, and a typical hematolysis was present in the haemolymph smear of WSSV-infected shrimp. Thirdly, necrosis and typical apoptosis of hemocytes were detected with TEM in the peripheral haemolymph of WSSV-infected shrimp. Hyalinocytes and semi-granulocytes with masses of WSSVs in their nuclei often appeared, whereas no granular hemocytes with WSSV were found in the hepatopancreas of moribund infected shrimps. All our results supported that hemocytes were the main target cells of WSSV, and hyalinocytes and semigranular hemocytes seemed to be more favorable for WSSV infection in F. chinensis.