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Xu W.-N.,Nanjing Agricultural University | Liu W.-B.,Nanjing Agricultural University | Shen M.-F.,Freshwater Fisheries Research Institute of Jiangsu Province | Li G.-F.,Nanjing Agricultural University | And 2 more authors.
Aquaculture International

We evaluated the effect of dietary protein and lipid on growth and body composition in juvenile red swamp crayfish (Procambarus clarkii). Nine groups of crayfish were fed nine experimental diets containing three levels of protein (24, 27, and 30 %) and three levels of lipid (4, 7, and 10 %) for 8 weeks. We used a 3 × 3 factorial model with four replicates and 12 crayfish (initial average weight, 2. 52 ± 0. 04 g) per replicate. We measured weight gain ratio (WG), specific growth rate (SGR), and body composition. WG and SGR were significantly (P < 0. 05) affected by dietary lipid but not significantly (P < 0. 05) affected by dietary protein. When grouped by lipid levels, the WG of crayfish fed diets containing 7 % lipid was higher than that of crayfish fed diets containing 4 or 10 % lipid. The diet containing 30 % protein and 7 % lipid promoted the most efficient growth (WG: 483. 38 %, SGR: 3. 14 % day-1). Dietary protein and lipid had no effect on condition factor or the viscous content (VC). Dietary protein, but not lipid, had a significant (P = 0. 038) effect on the muscle content (MC). Crayfish fed a diet containing 27 % protein and 4 % lipid had the highest (P < 0. 05) MC (16. 16 %). Dietary protein levels also had a significant (P = 0. 04) effect on the shell content (SC). SC was higher in crayfish fed a 30 % protein diet than in those fed 24 or 27 % protein. Proximate analysis suggested that crayfish fed a diet containing 27 % protein had a significantly higher nutritive composition than fish fed 24 or 30 % protein. Dietary protein also affected both whole body and muscle dry matter (DM) content. Similarly, both dietary protein and lipid affected whole-body crude lipid. Hepatopancreas DM, lipid content, and protein content were affected by dietary lipid. In conclusion, a diet containing 4-7 % lipid and 27 % protein with a protein to digestible energy ratio of 17-21 g protein·MJ-1 appeared optimal. © 2012 Springer Science+Business Media Dordrecht. Source

Lu S.,Shihezi University | Meng Y.,Freshwater Fisheries Research Institute of Jiangsu Province
Food Control

The microbial ecology of fermented sausages inoculated with different starter cultures (Pediococcus pentosaceus + Staphylococcus xylosus, batch A; Lactobacillus farciminis + Staphylococcus saprophyticus, batch B) was studied by culture-dependent and independent methods. The concentration of biogenic amines, pH and aw (water activity) were followed. The starter B can inhibit indigenous bacteria effectively judged by traditional microbiological method and PCR-DGGE fingerprint. There was no statistical difference in pH between batches A and B at 2 days when substantial amounts of BAs were produced, while the amounts of histamine, putrescine, cadaverine and tyramine in batch B was lower than in batch A significantly (P < 0.001). As a result, the starter cultures which can complete, grow well and inhibit amine-positive bacteria play an important role in reducing the production of BAs during ripening of fermented sausage. © 2009 Elsevier Ltd. All rights reserved. Source

Ge J.,Nanjing Normal University | Li J.,Freshwater Fisheries Research Institute of Jiangsu Province | Zhang J.,Nanjing Normal University | Yang Z.,Nanjing Normal University
Bulletin of Environmental Contamination and Toxicology

We studied the antioxidant responses of macrophyte Vallisnerria natans seedlings to combined ammonia (0, 0.21, and 0.85 mg L -1) and microcystin-LR (MC-LR) (0, 10, and 50 μg L -1) for 7 days. Results showed that superoxide dismutase, catalase (CAT), peroxidase, and glutathione were significantly induced by the mixtures of ammonia and MC-LR, and there were significant interactions between ammonia and MC-LR. Specially, CAT increased about fivefold at ammonia 0.85 mg L -1 and MC-LR 50 μg L -1 on day 3. Malondialdehyde fluctuated with both ammonia and MC-LR, and significant interactions were detected between the two stressors. Changes in all the measured variables were time-dependent. © Springer Science+Business Media, LLC 2012. Source

Chen Y.,CAS Nanjing Institute of Geography and Limnology | Li J.,Freshwater Fisheries Research Institute of Jiangsu Province | Sun H.,Nanjing Normal University | Yang Z.,Nanjing Normal University
Journal of Freshwater Ecology

Ammonia is one of the most common pollutants in aquaculture systems and its elevated concentration in surface water is a critical concern in fish larvae production. The purpose of this study was to assess the effects of un-ionized ammonia (NH3) on hatch success of fertilized eggs of silver carp Hypophthalmichthys molitrix and bighead carp Hypophthalmichthys nobilis, two ecologically and commercially important species in freshwater ecosystems. The results showed total hatch rates and viability of newly hatched larvae 24 h post-hatch decreased significantly with increasing NH3-N concentration for both silver carp and bighead carp, whereas abnormal rate increased significantly with increasing NH3-N concentration. When fitted to the data of total hatch rates and viability of newly hatched larvae 24 h post-hatch, it is clear that the logistic model with three parameters can be fitted to ecotoxicological data well and can describe dose-dependent effects of un-ionized ammonia on hatching success of fertilized eggs of both silver carp and bighead carp. According to the model, the EC50 for the hatch rates of silver carp and bighead carp was 0.98 and 0.86mg L-1, respectively. Our results should be useful to hatchery managers and fingerling producers in establishing acceptable water quality parameters for the hatchery and nursery ponds. © 2013 Taylor & Francis. Source

Qiu S.,Nanjing University | Huang S.,Nanjing University | Huang J.,Nanjing University | Pan J.,Freshwater Fisheries Research Institute of Jiangsu Province | Zhang W.,Nanjing University
Toxicology and Industrial Health

As a freshwater pearl mussel, Hyriopsis cumingii is widely cultured in China to produce pearls. This study was made to explore the antitumor activity of water-soluble polysaccharide (WSP) from mantles of H. cumingii. Cell viability of human hepatocarcinoma HepG2 cells was estimated by MTT method. Cell cycle analysis was determined by flow cytometry. Apoptosis was observed under fluorescence microscopy and confirmed by DNA fragment assay. Reverse transcriptase-polymerized chain reaction (RT-PCR) and immunocytochemistry were carried to evaluate c-myc, bcl-2 and cyclinD1 gene expressions in HepG2 cells. Furthermore, intracellular reactive oxygen species (ROS) production was assessed by flow cytometry. After WSP treatment, the growth of HepG2 cells was inhibited and most of cells arrested in G0/G1 phage (p <.01); apoptotic changes in nucleus and cytoplasm were also observed in WSP-treated cells; percentage of apoptotic rate significantly increased in a dose-dependent manner (p < 0.001); DNA fragmentation was detected in treated HepG2 cells; The mRNA level and protein level of c-myc, bcl-2 and cyclinD1 were decreased in the treated HepG2 cells. ROS was significantly increased in a dose- and time-dependent manner as well. The results suggested that WSP has potent antitumor activity. © The Author(s) 2010. Source

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