Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Publisher：日本環境毒性学会  

Exposure of animals to dioxin or similar environmental pollutants evokes responses by some drug-inducible genes that are measurable in the transcriptional level for using in the early detection system. Dioxin responsive elements (DREs) located in the 5' upstream regions of the <I>CYP1A</I> genes of fish and other animals play a key role in the drug-inducible genes expression. Of the two <I>CYP1A</I> genes reported in Japanese eel, several DREs are found to exist in the 5' upstream region of the <I>CYP1A1</I> (MC1) gene. However, no DREs was found within the 1631 bp upstream region of the second form of <I>CYP1A1</I> (MC2) gene in a &lambda; phage clone. In order to sequence further beyond the 1.6 kbp upstream region of the MC2 gene, a cosmid library was constructed with longer genomic fragments. We succeeded in obtaining a clone which contained both the MC1 and the MC2 genes including the further upstream region of the MC2 gene. Sequence analysis revealed that the clone contained, in addition to the 1.6 kbp region, a 3295 bp further upstream region containing eleven DREs. In MC1 as well as mammalian <I>CYP1A1</I> genes, the functional DREs are found in the proximity of transcription start site, whereas the DREs of the MC2 gene were localized beyond the 1.7 kbp upstream region, which contains unusual TAA repeats.

DOI： 10.11403/jset.6.45

Publisher：公益社団法人 日本水産学会  

A freshness index for fish muscle (K-value) was measured for six species of fish using freshness testing paper (FTP) and column chromatography. The correlation coefficient between these K-values determined by both methods was 0.917, although K-values of reddish muscle of big-eyed tuna, flying fish and common horse mackerel were evaluated lower by FTP than by column chromatography. The changes of K-values which were determined at regular intervals by FTP indicated that the decrease in freshness of amberjack and big-eyed tuna muscles was due to a first-order reaction. The kinetic parameters for the freshness-lowering, activation energy and frequency factor were obtained from Arrnhenius' plots of K-values at the storage temperatures between -1 and +20&deg;C, and then it was clarified that the quality of amberjack and big-eyed tuna with the different history of storage temperature should be predictable on the basis of these kinetic parameters.

DOI： 10.1046/j.1444-2906.2000.00024.x

Publisher：Japanese Society of Fisheries Science  

Publisher：水産増殖談話会  

小亜粒子リボゾームRNA遺伝子 (SSU rDNA) の2領域を対象に, スサビノリとアサクサノリのPCR-SSCP法による迅速判定を試みた。その結果, Tris-Glycine緩衝液と10%グリセロールを含む5もしくは6%アクリルアミドゲル (クロスリンクモノマー比2.0%) を用いることで銀染色による簡易検出が可能となった。アマノリ属SSU rDNAで多型の多くみられた586bpの解析には, 制限酵素断片のSSCP解析が1塩基変異を検出するのに有効であった。養殖ノリ13品種のPCR-SSCPパターンは, すべてスサビノリの泳動パターンを示した。本実、験に用いたPCR-SSCP改良法は, 4ステップ, 8時間で両種の判定が可能であった。

DOI： 10.11233/aquaculturesci1953.47.1

Publisher：公益社団法人 日本水産学会  

Lipases (triacylglycerol acylhydrolase, EC 3. 1. 1. 3) were purified from <i>Aspergillus repens</i> and <i>Eurotium herbariorum</i> NU-2 strain by using a DEAE-Sephadex A-50 column and preparative electrophoresis. The purified enzymes from <i>A. repens</i> and NU-2 had molecular weights estimated by SDS-PAGE to be 38, 000 and 65, 000, respectively. Lipase from <i>A. repens</i> had a pH optimum of 5.3 and a temperature optimum of 27&deg;C, while for the NU-2 strain corresponding values were pH 5.2 and 37&deg;C. The specific activity of NU-2 was about twice that of <i>A. repens</i>. Substrate specificity toward olive oil or triolein and positional specificity for hydrolyzing the 1 (3)-position ester bonds of triacylglycerol are discussed for both enzymes.

DOI： 10.2331/fishsci.65.274

Publisher：公益社団法人 日本水産学会  

DOI： 10.2331/fishsci.65.788

Publisher：Japanese Society of Fisheries Science  

Publisher：公益社団法人 日本水産学会  

DOI： 10.2331/fishsci.65.665

Publisher：Japanese Society of Fisheries Science  

Publisher：公益社団法人 日本水産学会  

The effects of urea concentration on the gel forming ability of shark muscle were investigated at two characteristic temperatures: aggregation was measured at 40&deg;C; and gelation was measured at 70&deg;C. When heated to 40&deg;C, the gel rigidity of myosin B decreased when the urea concentration was less than or equal to 1.0M, but it increased when the urea concentration was between 1.0 and 2.0M. The increase of gel rigidity can be attributed to the formation of an apparent network structure resulting from increasing disulfide bond levels. When heated to 70&deg;C, the rigidity decreased as the uniform network structure broke down with the increase of urea concentration. The microscopic observation and water distribution analysis revealed that the combined denaturing action of urea and heating resulted in a porous gel with a compact configuration and condensed myosin B network structure.

DOI： 10.2331/fishsci.64.776

Publisher：公益社団法人 日本水産学会  

Partial nucleotide sequences in the exonic region of a small subunit ribosomal RNA gene (ssr DNA) were analysed for nine commercially utilized species of <i>Porphyra</i> and eight laver cultivars in order to examine whether these sequences can be used to identify and discriminate between these species and cultivars. Pairwise comparisons of a total of 555 nucleotides revealed that there were from one to ninety-one nucleotide differences (substitutions and insertions/deletions) among the nine species. The one nucleotide difference found between <i>Porphyrayezoensis</i> and <i>P. tenera</i> was authentic, confirmed by repetitive sequence analyses of ssr DNA exonic regions using thalli of these species collected from five different locations. The nucleotide sequences of eight laver cultivars were identical to each other and also identical to field-collected <i>P. yezoensis</i> but not <i>P. tenera</i>. These results suggest that the nine <i>Porphyra</i> species can be distinguished from each other by comparison of the partial nucleotide sequences of the ssr DNA exonic region, while discrimination of laver cultivars is not possible by the comparison of only these sequences.

DOI： 10.2331/fishsci.64.886

Publisher：Japanese Society of Fisheries Science  

Publisher：公益社団法人 日本水産学会  

<i>Aspergillus repens</i>, a popular saprophyte in &ldquo;<i>katsuobushi</i>&rdquo; molding, induced the lipase and phospholipase production in the semi-defined liquid media containing 1% casamino acid and 20% glycine with the addition of olive oil or phosphatidylcholine, respectively. The mold consumed the free fatty acids, liberated from lipids contained in medium. These enzymes were detected inthe sliced product medium of broil-dried skipjack meat during the molding process, and the growth of <i>A. repens</i> caused the decrease of lipid content.<br> The distribution of glucosamine, indicator of mycelium growth, in commercial &ldquo;<i>katsuobushi</i>&rdquo; revealed that <i>A. repens</i> grew only on the surface. The results indicate that the molding process contributed to the hydrolysis of lipids by the enzymes andthe subsequent decrease of lipid concentration by the consumption of liberated free fatty acid on the surface of &ldquo;<i>katsuobushi</i>&rdquo;.

DOI： 10.2331/fishsci.62.594

Publisher：Japanese Society of Fisheries Science  

Publisher：Japanese Society for Food Science and Technology  

Conger eel (<I>Astroconger myriaster</I>) is prepared with a seasoning sauce prior to broiling or boiling. The sauce is discarded due to contamination by foreign materials and microbiological populations. Plant scale regeneration of the waste sauce was attempted by the combination of pasteurization, hydrolysis, concentration, centrifugation and filtration. Suspended proteins and meat particles were hydrolyzed with proteases to nitrogenous substances and amino acids. Unhydrolyzed solids were removed by centrifugation and filtration. Bacterial and fungal populations were decreased by pasteurization. Microorganism growth was suppressed by concentrating the dry matter to 45% along with the addition of sodium chloride up to a final concentration of 15% by weight. Recycling of waste sauce provided a regenerated seasoning sauce acceptable for conger eel processing and a reduction in the burden of waste water treatment.

DOI： 10.3136/nskkk.42.446

Publisher：The Japanese Society of Fisheries Science  

The quantitative method of ATP in fish muscle was investigated by the measurement of emitted light intensity using luciferase of the American firefly. The peak of the emitted light spectrum was shown at 554nm. The sensitive assay for ATP was improved by increasing the concentration of the enzyme with the presence of bovine serum albumin, DTT, and EDTA. The regression line was obtained between the emitted light intensity and the ATP concentra-tion in the ranges from 1 to 50&mu;M. The bioluminescent reaction was not inhibited by the dilu-tion of neutralized perchlorate as extractive solvent with 100 volumes of distilled water.<br> The ATP contents in the extracts of fish muscle were determined both by bioluminescent reaction and by column chromatography. The values obtained by the two different methods almost agreed. Consequently, the bioluminescent reaction of American firefly luciferase could be used for the rapid determination of the ATP contents in fish muscle.

DOI： 10.2331/suisan.58.1751

Publisher：日本水産學會  

To study the effects of urea on the denaturation of myosin B prepared from smooth dogfish, myosin B was kept at 20&deg;C for 10 min with various concentrations (0-3.0_M) of urea, and the reduced viscosity was measured as a parameter for structural changes in myosin B. The decrease in the reduced viscosity of myosin B containing urea above 1.0_M was similar to that of myosin in the presence of urea, However, the reduced viscosity of F-actin was slightly affected by urea even above 1.0_M.<br> The reduced viscosity of myosin B did not recovered to its initial level through the removal of urea at concentrations above 1.0_M urea, but that of myosin recovered perfectly through the re-moval of urea at concentrations up to 3.0_M urea. In the presence of urea above 1.0_M, myosin B irreversibly dissociated into myosin and actin. Therefore, it is concluded that the urea denaturation of myosin B would be attributed to its dissociation into myosin and actin as well as the conforma-tional changes of myosin molecules in the presence of urea above 1.0_M. Accordingly, shark myosin B is fairly stable under physiological concentrations of urea below 1.0_M.

DOI： 10.2331/suisan.58.1091

Publisher：The Japanese Society of Fisheries Science  

DOI： 10.2331/suisan.57.571

Publisher：The Japanese Society of Fisheries Science  

Effects of temperature on gel hardness of heat-induced meat paste gel and turbidity of myosin B solution prepared from shark muscle were investigated by applying to kinetics.<br> Their changes with time apparently proceeded to first-order reaction. The Arrhenius plots of their change rates for gel hardness and turbidity showed two straight lines with different slopes and indicated in the transition at 50 and 51&deg;C, respectively. On the other hand, the gel hardness changed little up to 40&deg;C and then increased to 70&deg;C. The turbidity increased at 40-50&deg;C and then decreased gradually on increasing the temperature. The typical network structure of heat-induced myosin B gel was observed above 50&deg;C by scanning electron micrographs.<br> The results described above showed that the gel-forming reaction system of meat paste from smooth dogfish muscle during heating could be divided into two characteristic temperature ranges: below and above 50&deg;C. The aggregation reaction takes place below 50&deg;C and the gelation reaction occurs above 50&deg;C.

DOI： 10.2331/suisan.56.1285

Event date： 2014.9

Language：Japanese  

Venue：福岡  

国内学会

Event date： 2013.9

Language：Japanese  

Venue：三重  

国内学会

Event date： 2012.9

Language：Japanese  

Venue：山口県下関市 独立行政法人水産大学校  

国内学会