魚肉の鮮度低下中における炭酸ガス発生について

　魚肉の鮮度と肉中の炭酸ガス(CO2)量との関係を見るために，この実験は行われた. 　サパ(Scomber jatonicus) の精肉を用い，鮮度低下過程中のCO2量をアルカリ吸収逆滴定の方法で実測した結果，発生CO2量は鮮度低下の初期においては急増したが，腐敗期においては漸減した. 従ってCO2量を以てその魚肉の鮮度指標とすることは良法ではないと論じた. 　魚肉中に発生するCO2は，無菌および菌接種試験の結果，その大部分が微生物作用により， 小部分 が筋肉の自己消化作用によるものであることを知った. 　なお，微生物の脱炭酸酵素の至適pHは酸性側にあるとされているが，微アルカリ性の魚肉からも相当量のCO2が発生した.これについて，微生物の脱炭酸酵素は適応酵素であるから， 例えば遊離のアミノ酸などの基質が豊富に存在するならば，微アルカリ性になった魚肉からもCO2は発生しうると推論した.Carbon dixoide (C02) content in the muscle of the mackerel (Scomber japonicus) during putrefaction was measured. (1) The quantity of C02 produced and accumulated in the sample of fish muscle increased quick to some degree in process of time, and then gradually decreased after the complete spoilage of the fish muscle. Accordingly, the C02 content of fish muscle might to be of little significance as a better index of the freshness of the fish flesh. (2) A large amount of C02 was produced by microbial actions, while a little amount of the gas was produced by muscle's autolysis. (3) Though the optimum pH for decarboxylases are on the acidic side, not a small quantity of CO2 was produced in fish muscle also at an alkaline pH. In this connection, it was discussed that microbial decarboxylases were inducible enzymes, and that they might therefore produce C02 to some extent on the alkaline side if such substrates as free amino acids were present in sufficient amounts, as it was often the case in a putrefying fish flesh

A study on the vertical distribution of vibrio parahaemolyticus in sea bottom

　腸炎ビブリオVibrio parahaemolyticusの底質における垂直分布状態、を知るために， 人工海底へ本菌を接種した実験，及び天然海底を垂直的に採泥した調査を行なった.その結果次のことが推定された. (1) 本菌の生物1型菌は， 底質の表層部に棲息分布しても深層部lこは生存し難い.この傾向は砂質において特lこ強かった.従って，前報で使用した採泥器の性能に砂質で1型菌が高率に検出された. (2) 生物2型菌は底質の砂・泥質にかかわらず，叉浅・深層に広く生存し得る.従って， 前報で2型薗が砂・泥質lこ広く検出された. (3) 生物1型菌が棲息する所lこは2型菌も分布する傾向があった. (4) 生物1型菌あるいは2型菌の生存とその環境底質のpH及び酸化還元電位とは，殆んど相関が認められなかった. (5) 泥質は，砂質に較べ有機物や窒素源が多量に含まれていた.このことは，本菌の分布と重要な関係があるものと考えられた.The present study was undertaken to investigate the distribution of Vibrio parahaemolyticus within columns of marine sediments in relation to the distance from the water-bottom interface. Both the laboratory experiment employing the 'artificial sea bottom' and the field survey in nearshore waters were conducted. The biotype 1 organisms of the bacteria were found only in the upper layers of the sediment in the case of sandy bottom, while their occurrence sometimes extended to somewhat deeper layers in the muddy bottom. The biotype 2 organisms inhabited both sandy and muddy bottom, ranging from water-bottom interface to a depth of 10 or 15 cm. It is therefore suspected that the tendency for the biotype 1 organisms to have been detected at high ratios from the sandy bottom, which was reported in the previous papers, was most probably due to the functional deficiency of the employed bottom sampler which was prone to sample the surface layer of sandy bottom and the deeper layers of soft muddy bottom. It is inferred that the want of nutriments was one of the major factors which precluded the occurrence of the biotype 1 organisms in deeper layers of sandy sea bottom

Distribution of vibrio parahaemolyticus in the Seto Inland Sea II : On the survey in winter

　1964年3 月12~16 日瀬戸内海中部水域における脱炎ビプリオ(Vibrio parahaemolyticus) の分布を調査した. ( 1 ) 生物1型菌が小豆島の南方海底と四国の高縄半島四方海底から分離検出された.生物2型菌は多度津沖の海底，広島湾の海水，呉沖の海底，三原港外の海水および福山港外の海水中から検出された. ( 2 ) 各生物型菌の検出頻度は夏季調査1) と較べて非常に少ない. しかし海水試料の層別および底質試料の組成別の検出頻度の傾向は夏季と相l似していた. ( 3 ) 生物l型菌が本調査で分離されたことは， その調査地点で越冬をしていたのではないかと思われるが，越冬条件については明らかでない.In the previous survey of this series') in which the distribution of Vibrio parahaemolyticus (FUJINO et al. 1951) SAKAZAKI et al. 1963 in the Seto Inland Sea in summer was investigated, the biotype 1 organisms of the bacterium were isolated at high ratio from the sandy sea bottoms. A similar survey was carried out in the central part of the Sea in March of 1964. The location of sampling stations is shown in Fig. 1 and Table 1. Biotype 1 (abbreviated I in Tables 2 and 3) were detected in the bottom samples from St. D and St. I, biotype 2 (abbreviated II in the Tables) were detected in the bottom samples from St. F and St. M and in the sea waters from St. L, St. N, and St. P. As is seen in Table 2, biotype III, an allied species, were detected only in one case, i. e., from the bottom sample of St. K. Detected frequencies of the organisms were very few, but as listed in Table 3, the results of the present and the previous surveys resembled each other in the tendency of the detected frequency. It was interesting to note that the biotype 1 organisms were found in sandy sea bottom in winter as well as in summer

A laboratory study on the resistivity of vibrio parahaemolyticus against low temperature

(1) 腸炎ビプリオVibrio parahaemolyticus の0℃以下における低温抵抗力を調べた. (2) 寒天培養基lこ接種し純粋培養状態で-20℃，-10℃ および0℃に放置すると，接種菌量により多少の長短はあるが，接種菌全部が相当短期間内lこ死滅した. (3)市販マグロ切身に接種して同様な放置試験を行なった結果は，短期間では全部が死滅しなかった. (4) 腸炎ビプリオ付着の恐れのある魚貝類を冷蔵・冷凍することによって，短期間に本菌を死滅させて食中毒を予防しようとすることはできないであろうと論じた.Vibrio Parahaemolyticus, a major causative organism of food poisoning in Japan, is known to bewidely distributed in the coastal sea areas, and it is supposed that the marine products, such as fishand cuttlefish, may be previously contaminated with the organisms in sea water before landing.Furthermore. it has seemed that the organism is weak under low temperature conditions. The present study was carried out on the resistivity of the organism for the culture at low temperature. On the pure cultures with an agar medium at -20, -10, and 0°C, they became extinct in a short period of storage time (Table 1 ). But on the similar experiments using tuna meat pieces inoculated with the organisms, a considerable number of them survived for a long time unexpectedly (Table 2). Therefore, from the food hygiene point of view, it was found that the insufficient refrigerated or frozen marine products which had been attacked by the organisms are no safe foodstuffs from the susceptible of poisoning

Distribution of vibrio parahaemolyticus in the Seto Inland Sea I : On the survey in summer

　1963年9月瀬戸内海東部水域， 1964 年9 月同西部水域の合計36 地点につき腸炎ビプリオ( Vibrio parahaemolyticus) の分布を調査した. (1) 生物1型菌は大阪湾，播磨灘，水島灘および周防灘南部から比較的多く検出された2型菌と類似菌は全水域から多く検出された. (2) 生物1型菌は海底砂質から2型薗は水深には無関係に海水から高率に検出された.類似歯は海水・底質共に広く分布しているようであった. (3) 本菌の分布と海況との関係については， この調査では特に有意と思われる相関は見出せなかった.The present survey was undertaken to investigate the distribution of Vibrio parahaemolyticus (FUJINO et al. 1951) SAKAZAKI et al. 1963 in the Seto Inland Sea in summer. The survey was carried out aboard the Toyoshio-maru, research vessel of Hiroshima University, in the eastern part of the Sea in September of 1963, and in the western part in September of 1964. The location of sampling stations is shown in Fig. 1 and Table 1. A selective liquid medium was prepared with 3% NaCI containing arabinose ethyl-violet broth as described by HoRIE et aJ. 4 ) and a BTB teepol agar medium was used to detect the bacteria according to the official method10 ) of the Japanese Ministry of Health and Welfare. Biotype I organisms (abbreviated I in Tables 2 and 3) of the bacterium, being believed to cause acute gastro-enteritis to man, were found to be widely distributed in Osaka Bay, Harima-nada, Mizushima-nada, and the southern part of Suo-nada as seen in Table 2. As listed in Table 3, moreover, biotype I was isolated at high ratio from sandy sea bottom. Biotype 2 (abbreviated II in the Tables) was isolated from extensive areas of the Sea and irrespective of the depths from the surface. An allied species (abbreviated III in the Tables) was felt to constitute considerable proportions in both sea water and sea bottom. In so far as this survey was concerned, the distribution of the bacteria had no relation to the values of such oceanographic properties as chlorinity, dissolved oxygen, or temperature

An Experiment on the Sulfate Reducing Activity of Sea Bottom Mud

古坂が水田土壌中の硫酸還元菌群の活性度をワールブルグ検圧計を用いて測定する方法を考案した.それを養殖場の海泥に応用した.即ち, 1. 海泥中に常在する呼吸基質を洗瀞除去する前処理を加えるならば,古坂の法が応用できることを知った. 2. 養殖場内外の海泥につき夏,秋および冬季について測定した結果,硫酸還元菌群の活性は2cmぐらいまでの表層部には全く認められず,10cmほどの深層部では夏季よりも秋季に強い傾向があり,冬季は全く認められなかった. 3. 硫酸還元菌群の活性の強弱と硫化物量とは必ずしも相関しないことを論じた.A method of the Warburg's manometry was reported by C. FURUSAKA for the evaluation of the activity of a sulfate reducer in paddy field soil. It was found that this method could be applied for sea bottom mud, if the mud were washed thrice in advance with a non-oxygen 3% sodium chloride solution in order to remove the sulfate present in the sample. According to his definition, the activity of hydrogen uptake was designated as a hydrogenase activity of mud (HA value in Table 1). In addition of a sulfite solution to the mud a significant increase in the rate of hydrogen uptake was further observed, the increment caused by the addition of the sulfite solution was designated as a sulfate reducing activity of mud (SRA value in Table 2), which is caused by the action of sulfate reducing bacteria in the mud. The mud samples collected from a fish farm bottom in the Seto Inland Sea were determined by a modified method. Considering the results in Table 2, there was no activity (SRA) at the layer from 0 to 2 cm mud depth, but considerable activity at the 10 cm mud depth. Moreover, it was suggested that the activities varied seasonally, rather higher in autumn than in summer and null in winter

水産動物のカロチノプロテインに関する研究 : V. アメリカザリガニ甲殻の加熱赤変について

甲殻を種々の条件下で加熱し,カロチノイド含量,及び組成の変化を調べ,甲殻の赤変との関係について論じた。 甲殻の赤変はカロチノイドと蛋白質の結合の解裂によってのみ生ずるものではなく,なんらかの蛋白質部分の変化による色素蛋白質の赤変によっても生ずると考えられる。 甲殻を加熱することによりアスタシンの増加は認められず,他のカロチノイド成分より優先的に分解を受けることを認めた。The carotenoid composition of crayfish exoskeleton before and after heat-treatments was determined in order to explain the mechanism of thermal denaturation of carotenoprotein. (1) The reddening of exoskeleton by boiling resulted not only from the splitting of carotenoid-protein link, but also from some structural modifications of the protein. (2) There was no evidence of the yield of astacin caused by heating of exoskeleton. (3) Violent heating decomposed astacin more heavily than other carotenoids in the exoskeleton

水産動物のカロチノプロテインに関する研究 : II アメリカザリガニのカロチノプロテインの赤変について

1. 天然の甲殻に存在する赤いカロチノプロテイン(R)は青又は紫カロチノプロテイン(B，P)の自動酸化により生じたものと考える. 2. RはB又はPを100℃に加熱して生じた赤いカロチノプロテイン(Rh)とは二・三性質を異にする. 3. B及びPの自動酸化，加熱により生ずるR，RhはB，Pよりカロチノイド含量が少なく，分子量は大きい. 4. B及びPを100℃加熱して生じたRhを長期間保存すると部分的ではあるが元のB，Pに回復することを認めた. 5. 0.005MのFe++，Fe+++，Sn++，Hg++，Cu++の存在によりカロチノプロテインは不可逆的に変性する.1. The red carotenoprotein present in the native exoskeleton of the crayfish (Cambarus clarkii) seemed to be a derivative resulted from the oxidation of blue or purple carotenoproteins. 2. The red carotenoprotein extracted from the exoskeleton was different in physical properties from the reddened one resulted by boiling. 3. The red carotenoproteins resulted from boiling and autoxidation had a lesser carotenoid content and showed a higher molecular weight than the bluish carotenoproteins. 4. It was found that the carotenoprotein reddened by heating at 100°C was partially reconverted to the original bluish carotenoproteins. 5. The presence of 0.005 M Fe++, Fe+++, Sn++, Hg++, and Cu++ caused irreversible denaturation of the carotenoproteins

水産動物のカロチノプロテインに関する研究 : I. アメリカザリガニ甲殻におけるカロチノプロテインの分布

1. 0.6M硫安を用いてアメリカザリガニ甲殻より赤，紫，青の三種のカロチノプロテイン(以下CPと略記)を得た.精製後の可視部の最大吸収波長は紫CP615mμ，青CP655mμであった，赤CPの最大吸収は前二者に比較して不明瞭であるが，475mμ付近にわずかな吸収を示した. 2. 甲殻における三穫のCPの分布は部分によって異なり，尾部，頭胸部等の青い甲殻は青CP及び紫CPを多く含み，赤い甲殻では赤CPの占める割合が青い甲殻よりも大きいことを明らかにした. 3. CPを硫安水溶液で抽出後なお赤い色が甲殻に残ることから，甲殻の色はCPのみによるものではなく，非結合型のカロチノイドとCPとの共存によるものと考察した.1. The blue and the purple carotenoproteins with absorption maxima at 655 and 615 mµ in 0.05 M phosphate buffer at pH 7.3 were obtained from the exoskeleton of the freshwater crayfish (Cambarus clarkii). Besides the above carotenoproteins, the red carotenoprotein which revealed a weak absorption around 475 mµ in visual region was separated in the exoskeleton. 2. Three kinds of carotenoproteins were distributed in various colored exoskeleton in different proportions. In the claws and limbs, the red carotenoprotein was found in somewhat larger degree than in the bluish carapace. 3. A fair amount of carotenoid-pigment remained in the exoskeleton after extraction by aqueous solution. This suggested the coexistence of carotenoproteins and unbound carotenoids in the pigmented exoskeleton

Changes of a Few Constituents in Purple Laver (Red Alga Porphyra) after Some Peiods of Storage in Frozen State

Changes in the TTC reducing ability and in the contents of a few chemical constituents were studied periodically on the fronds of Porphyra sp. during a six months storage in frozen state (-25℃). The results obtained can be summarized as follows: 1) The TTC reducing ability declined in the frozen fronds either stored in the air or in nitrogen gas; it dropped to one tenth and one fifth of the initial level, respectively, after six months storage. In both cases, rapid decrease occurred during the first two months of freezing storage. 2) Chlorophyll a contents were almost constant in the fronds during the storage. 3) Little changes were observed in the total nitrogen contents of the fronds regardless to the storage period. 4) Extractive amino acids such as aspartic acid, glycine, alanine, isoleucine and threonine and/or serine showed tendencies to decrease during the storage. Among these amino acids, aspartic acid and isoleucine had the most conspicuous rates of diminution. 5) Extractive nitrogen contents in the frozen thalli decreased gradually to about 60% in the air and to about 70% in nitrogen gas within the six months