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11.
Rekha D. Chakraborty P. K. Surendran 《World journal of microbiology & biotechnology》2008,24(9):1929-1935
This study was aimed for the detection of Vibrio parahaemolyticus by biochemical and molecular methods in seafood samples collected from the markets of Cochin located at the southwest coast
of India. A total of seventy-two V. parahaemolyticus cultures were isolated by selecting sucrose and cellobiose non-fermenting colonies. All the biochemically confirmed strains
were found to have 368-bp toxR gene fragment, while an additional 24% of the samples were confirmed as V. parahaemolyticus by toxR based polymerase chain reaction (PCR) from enrichment broths. PCR based methods are used to detect tdh, trh, and orf8 genes for the identification of pathogenic and pandemic V. parahaemolyticus. Only one out of two urease positive isolates amplified the trh (500bp) gene. About 10% of the isolates showed weak haemolysis and none were found to amplify tdh (269 bp) and orf8 (746 bp) genes, thus indicating the meager incidence of pandemic strains from this area. The incidence of trh positive isolates from market samples signals towards the adoption of stringent seafood safety measures for the products
meant for human consumption. 相似文献
12.
Amir Neori 《Journal of applied phycology》2008,20(5):567-570
Ecologically friendly aquaculture crops, such as seaweeds, herbivores, omnivores, and detritivores can be cultured using relatively
less of our limited natural resources and produce relatively less pollution. They also top FAO’s estimates of aquaculture
crops for the 21st century. These crops already comprise nearly 90% of global aquaculture tonnage, >90% of all aquaculture
production in China and >60% of production even in North America. Consumers prefer them, most likely due to their low prices.
Production costs of organisms low on the food chain are low due to the ability of these organisms to efficiently utilize low-cost,
mostly plant-based diets and to recycle their own waste. Thus, ecologically friendly aquaculture is not a dream but a dominant
global reality. The less ecologically-friendly aquaculture of salmon, sea bream, fed shrimp, among others, has attracted public
opposition to aquaculture, but these crops totaled approximately only 10% of global production in 2004. The profitability
of industrialized monocultures of these crops is threatened further by rising costs of energy and feed, environmental regulation
compliance, disease, and public opposition. Current monoculture practices and perceptions intrinsic to the aquaculture industry
can be turned around into a vision of sustained profitable expansion of carnivores production with trophically lower organisms
in ecologically-balanced aquaculture farms. This category of aquaculture, which is the modern intensive form of polyculture
practiced in Asia, feeds the waste of carnivore culture to lower trophic level organisms, primarily algae and mollusks. Species
are selected based on their ecological functions in addition to their economic potential. Ecologically-balanced farms turn
the costly treatment of carnivore waste outside the farm to a revenue-generating process of biofiltration, conversion, and
resource recovery into plant and mollusk crops inside the farm. In doing so, they solve several of the major problems faced
by modern aquaculture. The aquaculture industry can protect its own interests – and reap major benefits – by understanding
the importance of ecological balance, the potential of seaweeds as components in feeds, and the importance of the culture
and R&D of low trophic level organisms. The industry should also accept the relevance of environmental, social, and image
aspects of aquaculture to its success. Governments have the tools to reward multi-trophic farms with seaweeds by means of
tax credits and nutrient credits and to penalize unbalanced monoculture approaches by means of ‘polluter pays’ fines, thereby
providing the multi-trophic farms with a significant economic advantage. Such measures have been discussed, but their implementation
has been slow. 相似文献
13.
Friederike Ziegler Daniel Valentinsson 《The International Journal of Life Cycle Assessment》2008,13(6):487-497
Background, aim, and scope Two fishing methods, creeling and conventional trawling, are used to target Norway lobster (Nephrops norvegicus), economically the second most important species in Swedish west coast fisheries. The goal was to evaluate overall resource
use and environmental impact caused by production of this seafood with the two different fishing methods using life cycle
assessment (LCA) methodology.
Materials and methods The inventory covered the entire chain starting by production of supply materials and the fishery itself, through seafood
auctioning, wholesaling, retailing, to the consumer. That portion of the life cycle occurring on land was assumed to be identical
for Norway lobsters regardless as to how they were caught. The functional unit was 300 g of edible meat (i.e., Norway lobster
tails), corresponding to 1 kg of whole, boiled Norway lobsters. The seafloor impact of trawling was quantified using a recently
developed methodology.
Results Major differences were found between the fishing methods with regard to environmental impact: creeling was found to be more
efficient than conventional trawling in all traditional impact categories and in the two additional fishery-related categories
involving seafloor impact and discarding. Since the quality of the creel-caught Nephrops was higher, the difference was probably even higher than indicated here.
Discussion Major improvement potential was identified in the more widespread use of creels and species-selective trawls. The only deficiencies
of creel fishing were poorer working environment and safety, and a potentially higher risk of recruitment overfishing. However,
these issues could be handled by technological development and fisheries regulations and should not hamper the development
of creel fishery.
Conclusions Improvement options were identified and quantified for the Swedish Nephrops fishery. The study demonstrates how LCA can be used to compare the environmental performance of different segments of a fishery.
Recommendations and perspectives Shifting to creeling and species-selective trawling would lead to considerably lower discard, fuel use, and seafloor impact
while providing consumers with the same amount of Norway lobsters.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
Salmonella enterica subsp. enterica Typhimurium and Salmonella enterica subsp. enterica Derby strains isolated from different seafood were genotyped by PCR-ribotyping and ERIC-PCR assays. This study has ascertained the genetic relatedness among serovars prevalent in tropical seafood. PCR-ribotyping exhibited genetic variation in both Salmonella serovars, and ribotype profile (II) was most predominant, which was observed in 10/18 of Salmonella enterica subsp. enterica Typhimurium and 7/17 Salmonella enterica subsp. enterica Derby isolates. Cluster analysis of ERIC-PCR for Salmonella enterica subsp. enterica Typhimurium strains exhibited nine different banding patterns and four strains showed >95% genetic homology within the cluster pairs. ERIC-PCR produced more genetic variations in Salmonella enterica subsp. enterica Typhimurium; nevertheless, both methods were found to be comparable for Salmonella enterica subsp. enterica Derby isolates. Discrimination index of PCR-ribotyping for Salmonella enterica subsp. enterica Typhimurium isolates was obtained at 0.674 and index value 0.714 was observed for Salmonella enterica subsp. enterica Derby strains. Molecular fingerprinting investigation highlighted the hypothesis of diverse routes of Salmonella contamination in seafood as multiple clones of Salmonella enterica subsp. enterica Typhimurium and Salmonella enterica subsp. enterica Derby were detected in same or different seafood throughout the study period. 相似文献
15.
Protective effects of selenium against mercury toxicity have been demonstrated in all animal models evaluated. As interactions
between selenium and mercury and their molar ratios in seafood are essential factors in evaluating risks associated with dietary
mercury exposure, considering mercury content alone is inadequate. In this study, the absolute and molar concentrations of
mercury and selenium were determined in edible portions from 420 individual fish representing 15 species of pelagic fish collected
from the central North Pacific Ocean near Hawaii. Selenium was in molar excess of mercury in almost all fish species evaluated.
The rank order of mean Se/Hg molar ratios was striped marlin (17.6) > yellowfin tuna (14.1) > mahimahi (13.1) > skipjack tuna
(12.8) > spearfish (11.4) > wahoo (10.8) > sickle pomfret (6.7) > albacore tuna (5.3) > bigeye tuna (5.2) > blue marlin (4.1) > escolar
(2.4) > opah (2.3) > thresher shark (1.5) > swordfish (1.2) > mako shark (0.5). With a Se/Hg molar ratio of less than 1, mako
shark was the only fish containing a net molar excess of mercury. A selenium health benefit value based on the absolute amounts
and relative proportions of selenium and mercury in seafood is proposed as a more comprehensive seafood safety criterion. 相似文献
16.
Fish and seafood are main contributors of arsenic (As) in the diet. The dominating arsenical is the organoarsenical arsenobetaine (AB), found particularly in finfish. Algae, blue mussels and other filter feeders contain less AB, but more arsenosugars and relatively more inorganic arsenic (iAs), whereas fatty fish contain more arsenolipids. Other compounds present in smaller amounts in seafood include trimethylarsine oxide (TMAO), trimethylarsoniopropionate (TMAP), dimethylarsenate (DMA), methylarsenate (MA) and sulfur-containing arsenicals. The toxic and carcinogenic arsenical iAs is biotransformed in humans and excreted in urine as the carcinogens dimethylarsinate (DMA) and methylarsonate (MA), producing reactive intermediates in the process. Less is known about the biotransformation of organoarsenicals, but new insight indicates that bioconversion of arsenosugars and arsenolipids in seafood results in urinary excretion of DMA, possibly also producing reactive trivalent arsenic intermediates. Recent findings also indicate that the pre-systematic metabolism by colon microbiota play an important role for human metabolism of arsenicals. Processing of seafood may also result in transformation of arsenicals. 相似文献
17.
18.
The ‘Wild Seafood’ Provisioning Service (WSPS), on which commercial fisheries rely, is probably one of the best studied marine ecosystem services due to its economic relevance and because extensive information sources exist for assessment purposes. Yet, the indicators often proposed are not suitable to describe the capacity of the ecosystem to deliver the WSPS. Therefore this study proposes surplus production (SP), a well-established concept in fisheries science, as the basis to calculate the capacity of marine ecosystems to provide the WSPS. SP is defined as the difference between stock production (through recruitment and body growth) and losses through natural mortality. This is, therefore, the production of the stock that could be harvested sustainably without decreasing the biomass. To assess the sustainability of the exploitation of the WSPS we also developed an indicator for this based on SP and compared it to existing fisheries management indicators. When both SP-based indicators showed a decreasing trend, contrasting with an increasing trend in the existing fisheries management indicators, the calculation of the SP-based indicators was scrutinized revealing that the weighting of the stocks into an aggregated indicator, strongly determines the indicator values, even up to the point that the trend is reversed. The aggregated indicators based on SP-weighted stocks can be considered complementary to existing fisheries management indicators as the former accurately reflect the capacity of the commercial fish to provide the WSPS and the sustainability of the exploitation of this service. In contrast the existing fisheries management indicators primarily reflect the performance of management towards achieving fisheries-specific policy goals. 相似文献
19.
Parvathi A Sanath Kumar H Kenchanna Prakasha B Lu J Xu X Hu W Feng Z Karunasagar I Karunasagar I 《Experimental parasitology》2007,115(3):291-295
Clonorchis sinensis is a fish-borne trematode endemic to East Asia, which infects over 35 million people globally. In the study described here, we developed a nested polymerase chain reaction (PCR) method for the specific and reliable detection of C. sinensis. The primers designed from the nucleotide sequence data derived in this study were evaluated for their specificity and sensitivity for the detection of C. sinensis. The specific amplification products were obtained only with C. sinensis and no amplifications occurred with the DNA of closely related trematodes including Opisthorchis viverrini demonstrating the specificity of the assay. The novel PCR method described here will be useful for the quarantine of fishery products and evaluation of transmission status of clonorchiasis in the endemic areas. 相似文献
20.
副溶血弧菌是水产食品中的一种重要食物中毒菌,它在沿岸海水和海产动物体上都有广泛的分布,所以它又是海产动物的一种条件性致病菌。本文报告了该菌在青岛近岸海水和几种常见的水产食品上污染了该菌的情况,在检测方法上也进一步修定了一种选择性较强的培养基(SAC)。调查发现青岛近岸海水中副溶血弧菌的出现率为68~463CFU/100ml,几种常见海产食品中平均含量值为745~6900CFU/100克,其中贝类含量最高达6900/100克。采用常用的选择培养基“TCBS”等与修定的“SAC”对该菌进行检测比较,结果表明“SAC”法较“TCBS”法检出的阳性率和灵敏性均较高,两种方法X~2=4.28,P>0.05,效果有显著的意义。 相似文献