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Volume 53, Issue 2
Displaying 1-26 of 26 articles from this issue
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Masaharu Ohgai, Kaoru Takesue1987 Volume 53 Issue 2 Pages 173-175
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe study dealt with the relationships between the quality of nori fronds and the diatoms attached to them in the nori cultivation ground. The investigations were carried out for quantita-tive analyses of total nitrogen and total phosphorus in each frond collected monthly and classified into five specimens according to the cell numbers of diatoms.
The quality gradually declined after the middle period of cultivation, and declined further as the diatoms were attached to the fronds. The contents of total nitrogen and total phosphorus were high in the fronds with few cell numbers of diatoms, and as the cell numbers increased, the contents decreased. It was concluded that in the case of the fronds with over 2.5×104 cells/cm2 of diatoms attached, the fronds were inferior in quality. The validity was ascertained on commercial sheets of dried nori.View full abstractDownload PDF (210K) -
Toyomi Takahashi, Tatsuaki Maeda, Yasuhiro Tsuchiya, Toshikuni Nakatan ...1987 Volume 53 Issue 2 Pages 177-187
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSFrom August 1977 to February 1983, the distributions and food habits of righteye flounders Limanda herzensteini and L. yokohamae in Mutsu Bay, Aomori Prefecture, were investigated. Results of tagging experiments conducted for six years suggested that both species in the bay hardly migrated outside it. In winter they were found chiefly in West Bay. In the other seasons L. herzensteini concentrated in West Bay or western part of East Bay, or both, while L. yokohamae in the eastern part of East Bay. L. herzensteini fed chiefly on polychaetes, sea-hares, bivalves, and ophiuroides from spring to autumn and in winter fish and macrurans became very important in their diet. On the other hand, L. yokohamae fed exclusively on polychaetes throughout the year. There was a considerable difference in species selection for prey and food composition in stomachs between the two species. However, ingested-food compositions did not differ very much between the two species in the same area, suggesting that they need a similar food resource and so compete potentially for food and habitat.View full abstractDownload PDF (921K) -
Toyomi Takahashi1987 Volume 53 Issue 2 Pages 189-194
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIntraspecific relationships for food in righteye flounders Limanda herzensteini and L. yokohamae in Mutsu Bay, Aomori Prefecture, were studied. In both species, body length distributions did not differ very much among sea areas. In spring (May), the size (by wet weight) of prey in L. her-zensteini stomachs was independent of fish length. But in summer, the prey size ingested by L. herzensteini became larger sequentially with increase of fish length, indicating the existence of strong size selection for prey. The same was apparent for L. yokohamae. Intensity of size selection of both species was closely related to the food availability and the intensity of food requirement in relation to their annual life period. Namely, the size selection was found as high abundance of food and inactive feeding of fish. These results suggested that the intraspecific competition for food in L. herzensteini may possibly occur in spring but in summer it becomes weak because they ingested prey of different size with fish length. On the other hand, for L. yokohamae, considering that in spring the kind of prey ingested by them depended on fish length, it seems probable that there is less likelihood of intraspecific competition for food at least during spring and summer.View full abstractDownload PDF (461K) -
Tadahisa Seikai, Takeshi Watanabe, Masumi Shimozaki1987 Volume 53 Issue 2 Pages 195-200
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThree geographically different strains of Artemia (Brazil 1981, Tien-tsin; China 1981 and San Francisco Bay; USA 1981) were used in this study, Chemical components of these 3 strains of Artemia were analyzed and the influences of their nauplii on occurrence of albinism in hatchery -reared Paralichthys olivaceus were examined.
Larval flounder of 9-10 days post-hatching (5.50±0.32mm TL) which had been fed initially with only rotifers were given one of 3 different strains of Artemia nauplii mixed with rotifers until the flounder's completion of metamorphosis. Then the percentage occurrence of albinism was compared among 3 groups of flounder (BA, TA and SA) fed respectively on Artemia nauplii in Brazil, Tien-tsin and San Francisco. The percentage occurrence of albinism was highest (99.5-100.0%) in BA, intermediate (81.3-84.6%) in TA and lowest (21.1-26.1%) in SA. Population density, feeding level and the other rearing conditions in BA were almost the same as those in SA. These results suggest a close relationship between some chemical components of Artemia nauplii and the occurrence of albinism in flounder. However, principal factors in Artemia responsible for abnormal coloration were not specified from the difference of chemical components among these 3 different strains in terms of minerals, heavy metals, lipid class, fatty acids and residual pesticides.View full abstractDownload PDF (472K) -
Fulvio Salati, Yuji Ikeda, Riichi Kusuda1987 Volume 53 Issue 2 Pages 201-204
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe effects of Edwardsiella tarda lipopolysaccharide (LPS) on the immune response of eel were studied by determination of antibody titer and phagocytic activity of the blood and by determina-tion of survival rate to experimental challenge. Crude LPS and formalin killed cell (FKC) of E. tarda were injected twice intramuscularly in the eels. To compare the protective effect of the pre-parations, the eels were challenged with 2.4×107 cells/fish of live E. tarda, strain EF-1.
The agglutination antibody titer of both LPS and FKC immunized eels was high when com-pared to the controls. In vitro phagocytic activity of the total blood was high in both LPS and FKC immunization groups than that found in the control group, whereas the higher average ac-tivity was shown in the LPS immunization group. Only the eels immunized with LPS preparation showed survival to the experimental challenge. The results in the eel confirm the capacity of the LPS to increase not only the antibody titer, but also the level of phagocytosis and the protection to the infection.View full abstractDownload PDF (294K) -
Riichi Kusuda, Yuji Ikeda1987 Volume 53 Issue 2 Pages 205-209
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSStudies on morphological characterization of eel leucocytes and phagocytosis against Edward-siella tarda were performed. For morphology, peroxidase-Giemsa stain was used, For in vitro phagocytosis test, both whole blood culture and separated leucocyte culture were used. The morphological study revealed: lymphocyte-like cell of 5-10μm, round, round nuclei and dark gray cytoplasm. Thrombocyte-like cell of 8-10μm in length, 3-5μm in width, spindle shape, oval nuclei and light pink cytoplasm. Neutrophil-like cell of 10-15μm, round or oval, oval or bilobed nuclei and whitish-gray or whitish cytoplasm. Monocyte-like cell of 10-15μm, round, round or oval nuclei and light to dark gray cytoplasm. Only a few neutrophil-like cells showed peroxidase positive granules. Many neutrophil-like cells and other leucocytes showed no pero-xidase positive granules. Phagocytosis was observed with thrombocyte-like, neutrophil-like and monocyte-like cells, Lymphocyte-like cells showed no phagocytosis. Thrombocyte-like cells showed very weak phagocytosis. Neutrophil-like and monocyte-like cells showed active phago-cytosis.
As results it may be appropriate to conclude that the eel leucocytes could be classified as lymphocytes, thrombocytes, neutrophils and monocytes.View full abstractDownload PDF (1982K) -
Riichi Kusuda, Itsuro Kawahara, Masami Hamaguchi1987 Volume 53 Issue 2 Pages 211-214
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSActivities and partial characterization of lysozyme in the skin mucus extract, serum and kidney extract of yellowtail Seriola quinqueradiata, were investigated. The lysozyme activities were measured using acetone-ether dried cells of Micrococcus lysodeikticus as substrate. The lysozyme activities in the skin mucus extract, serum and kidney extract were 0.69, 3.00 and 2.23μg/mg protein, respectively. The optimal pH for the lysozyme activities of skin mucus extract was around 7.0, whereas that of serum and kindey extract were around 8.0. The optimal temperature for the lysozyme activity of skin mucus extract was around 40°C, and similar results were obtain in serum and kidney extract. The lysozyme activities were relatively stable to heat, and remained active when heated at 50°C for 10min. The lysozyme activities were inhibited by incubation with EDTA and were inactivated when chitin coated cellulose was added to the samples.View full abstractDownload PDF (325K) -
Tsutomu Kobata1987 Volume 53 Issue 2 Pages 215-218
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe annual catches of adult yellowtail Seriola quinqueradiata by large set nets in the three regions, Sagami Bay, Mie and KÔchi along the Pacific coast of Japan agree in long-term fluctuation, but do not agree in short-term fluctuation. In order to grasp this phenomenon, correlation coef-ficient in the voluntary periods more than 4 years between the catches have been investigated by the long-term catch records after 1899.
The results are summarized as follows;
1) There are no fixed relations of the catches between any two regions in the short-term cor-relation which change by age.
2) Frequency of significant positive correlation coefficient increase with the increase of time scale of data. Ratio of the frequency arrives at 100% in the long-term correlation for more than 30 or 45 years. This result agrees with those of past researches.
3) Significant negative correlation coefficients appear in the short-term correlation within about 10 years. But ratio of the frequency is very low and is almost negligible for more than 10 years correlation.
4) Based on scatter diagram of the catches, long-term fluctuations of correlation between the catches are constructed with short-term fluctuation of the correlations which are shaped as blocks by centering nearby years.
5) The correlation coefficients within each block are negative correlation. This result agrees with the fishermen's opinion.View full abstractDownload PDF (318K) -
Jun Kohbara, Shiro Murachi, Kenji Nanba1987 Volume 53 Issue 2 Pages 219-222
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe vascular architecture of hyaloid vessel in carp eye was investigated using the trypsin digestion method. At the center of the optic disk, the hyaloid arteries branch off in radial direc-tions and proceed to the peripheral region of the retina. The branching of hyaloid arteries was divided roughly into two types. One is the dichotomous (Y-shaped) branching having two branches of equal diameter. The other is the side-arm branching which comes off at right angles from thick arteries. It was suggested that the former plays an important role in the blood trans-portation to the peripheral region. On the other hand, the latter contributes to extending the region of blood supply by making capillary plexus between the thick arteries. The capillaries come together again and form veins between the thick arteries. Both the capillaries and the veins anastomose to the annular vessel which run circularly on the ora terminalis. In addition, in contrast with almost all vessels anastomosing to the annular vessel, some capillaries seen in the neighborhood of the optic disk come back again to this disk. Thus, there are two efferent blood streams in the hyaloid vessels.View full abstractDownload PDF (1190K) -
Ichiro Hara1987 Volume 53 Issue 2 Pages 223-227
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe flight surveys were conducted in the waters off the southeast coast of Hokkaido where a big catch of sardine Sardinops melanosticta has been taken during summer and autumn seasons. In order to examine the swimming speeds of schools, two kinds of survey, such as experiments and observations, were conducted near the fishing ground on Oct. 9 and Sept. 29, 1985 respectively. In the experiments five floaters were airdropped at a regular interval to intersect the target schools from the rear to the front. After that, relative changes between the school and the floaters were compared. On the other hand, the observations was carried out shuttling the same transect in order to observe the movements of a number of schools. From the results of the experiments the cruising speeds lie between 1.2-4.1BL/s (0.4-1.5kt). The result obtained by the observation was 4.3kt, which was larger compared with the data described above. The schools which were chosen as the subject in the experiments were elongate in shape and the longest dimensions of the schools ranged from 300-1, 500m. The results may suggest that the size of schools have an effect on the speed, as the speed of school decreases with an increase in size.View full abstractDownload PDF (349K) -
Somsri Ngamvongchon, Law Yean Kok, Fumio Tahashima1987 Volume 53 Issue 2 Pages 229-234
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSLHRH analogue [(D-Ala6-desGly10) LHRH ethylamide] injection at a dose of 30μg/kg body weight accelerated spermiation in carp. The amount of collectable milt increased rapidly at 12h after injection and was maintained at high levels for 24h. The spermatocrit gradually in-creased throughout the experiment, and motility of the spermatozoa did not appear to be affected.
Plasma gonadotropin (GtH) level showed a significant rise at 5min after the LHRH analogue injection. The level decreased at 40min but increased again gradually and reached a peak at 24h. The control group had a lower plasma GtH level than the injected group throughout the experiment. Plasma testosterone increased significantly from 1h and was maintained at a high level for 24h. Plasma 11-ketotestosterone also showed a similar pattern of changes. No signi-ficant changes were recognized for both androgens in the control fish.
From these results, it is possible to postulate that exogenous LHRH analogue stimulated an early and rapid discharge of gonadotropin from the pituitary gland, and that spermiation was enhanced by the action of the successive secretion of gonadotropin and androgens.View full abstractDownload PDF (1553K) -
Takashi Nakanishi1987 Volume 53 Issue 2 Pages 235-237
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSOxygen consumption (VO2) of larvae and post-larvae of king carb Paralithodes carntschaticus was measured at 3, 8, 13 and 18°C. Effect of hypoxia on ?? 02 was also measured at 3, 8 and 13°C.
The oxygen consumption from first zoeal stage to first adult-form larva stage at 3C° was almost the same. The oxygen consumption at third zoeal stage at 8°C peaked and then decreased from this stage.
A homoeostasis of ?? 02 at zoeal, glauchothoe and first adult-form larva stage was observed at oxygen saturation of 70-80% but the gradient at first adult-form larva stage was above those at zoeal and glauchothoe stage.View full abstractDownload PDF (177K) -
Mamoru Yoshiya, Akihiko Kuwahara, Yuichi Hamanaka1987 Volume 53 Issue 2 Pages 239-247
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe present study examined the influence of algal vegetation and hydrographic conditions on the growth and survival of the young topshells. These were artificially incubated and cultured in tank until growing up to 8-10mm in shell height during about one year, and then were released to several shallow and rocky coastal areas of Kyoto Prefecture.
Favorable algae for growth of the topshells were Gelidiaceae, Ulva and microalgae such as Ceramium sp. and Herposiphonia subdisticha which were growing on the Corallinoideae. However, Corallinoideae and Sargassum spp. were unfavorable algae for the young topshells. For example, in the case of Port Niizaki, the topshell released in the patch of Pterocladia capillacea grew up to 28.5mm in mean shell height in 124 days, whereas the topshell released in the area where only Corallinoideae and Dictyota dichotoma grew up to 21.0mm only.
The survival rates of the topshell in the experimental areas exposed to relatively little wave action were 53.6-93.8%. On the other hand, the rate was only 12.1% in Aoshima exposed to the oceanic swell and wave action.
According to the above results, it is suggested that favorable areas for the topshell of 8-10mm in shell height were under conditions covered with Gelidiaceae and Ulva, and without oceanic swell and strong wave action.View full abstractDownload PDF (681K) -
Osame Tabeta, Hisomu Terasaki1987 Volume 53 Issue 2 Pages 249-251
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSAn ovary-like organ was observed on the lower side of the right preopercle of a male puffer Takifugu rubripes (Temminck et Schlegel), which had a body weight ca 6kg and a testis weight ca 600g. This puffer was caught in Ainoshima Island, Kitakyushu City, Japan, on January 24, 1982. The organ was oval in shape, and the size of a ping-pong ball (ca 20g), and was separated by thin membranes into more than 4 parts. Two groups of eggs were observed: large-sized (0.75-0.95mm; mean 0.80mm in diameter) and small-sized (0.45-0.55mm; 0.50mm). The latter were far more numerous than the former. Histologically, yolk vesicles or yolk globules in all the eggs formed a large mass and were in a state of liquefaction. No clear nucleuses were observed in almost all the follicle and ovarian stomal cells and the eggs, indicating deterioration. The organ and surrounding muscles were found to be non-toxic (less than 5 MU/g). The extra-regional ovary-like organ from T. rubripes, and migration of primordial germ cells to the intermuscular connective tissues of the head region in teleost were recorded for the first time.View full abstractDownload PDF (1308K) -
Yasuhiro Fujioka1987 Volume 53 Issue 2 Pages 253-260
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSParr-smolt transformation, growth rate, maturity and appearance or disappearance of red spots on the body were observed in juvenile biwa salmon Oncorhynchus rhodurus indigenous to Lake Biwa, reared in pond for eighteen months, and compared with those of amago salmon reared under the same conditions. Biwa salmon transformed from juvenile parr to silvery smolt in underyearling June to July (standard length 7.5-8.0cm), and 60-80% remained as smolt till yearling autumn, Smolts of amago salmon appeared mainly in underyearling September to yearling March, and all of them transformed back to parr or silvery parr by yearling May. Most of the smolt of biwa salmon, unlike those of amago and masu salmon, did not show complete silvering of body color or intense blackening at outer extremities of dosal fin. Growth after smolt transformation in biwa salmon was slower than that of amago salmon, though there was no significant difference between the juveniles of biwa and amago salmon in underyearling April to May. Almost all of the amago salmon matured in yearling autumn, wherease only a part of the biwa salmon males matured at the same time. Red spots appeared on body of almost all of the amago salmon, and the number and density increased with growth. On the contrary, those of biwa salmon decreased during smolt transformation, though a few red spots existed at parr stage. Thus biwa salmon differed from amago salmon in several characteristics during smoltification.View full abstractDownload PDF (1449K) -
Attaya Kungsuwan, Yuji Nagashima, Tamao Noguchi, Yasuo Shida, Sunee Su ...1987 Volume 53 Issue 2 Pages 261-266
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSFurther attempts were made to identify the toxins of the horseshoe crab Carcinoscorpius rotundicauda which causes sporadically food poisonings in Thailand.
Toxic C. rotundicauda eggs were crushed and extracted with water repeatedly. After being defatted with dichloromethane, the combined extracts were ultrafiltered to cut off more than 1, 000 dalton-substances. Toxic fractions were obtained from the filtrate by column chromatography on Bio-Gel P-2 and Bio-Rex 70.
Cellulose acetate strip electrophoresis, TLC, HPLC, and other instrumental analyses demon-strated that the horseshoe crab toxin was essentially composed of tetrodotoxin and related sub-stances, along with paralytic shellfish poisons as minor components.View full abstractDownload PDF (375K) -
Takuma Sasaki, Hiroyuki Uchida, Noriko A. Uchida, Nobuo Takasuka, Yaku ...1987 Volume 53 Issue 2 Pages 267-272
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe liquid from heat treatment of the well-known scallop Patinopecten yessoensis which would normally be discarded as waste has been found to contain a new glycoprotein antineoplastic agent. The fraction composed of 16.8% carbohydrate, 64.5% protein, 2.7% lipid, and 1% nucleic acid exhibited strong antitumor activity. We studied the effects of this fraction on the in vivo growth of tumors. It inhibited tumor growth when injected locally or systematically. Inhibition was not due to direct toxic effects but probably to stimulation of host-mediated responses.View full abstractDownload PDF (515K) -
Shuichi Satoh, Toshio Takeuchi, Takeshi Watanabe1987 Volume 53 Issue 2 Pages 273-279
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSChanges in mineral composition at some defined stages of developing eggs of rainbow trout and after feeding swim up fry with diets with or without supplement of various trace metals for 40 weeks were determined. The contents of K, Mg and Na changed largely until 12th week after feeding, and then became constant. Levels of Ca and P reached almost plateau at the stage of 20 weeks after swim up, which was 8 weeks later than those of K, Na, Mg and Fe. Concentrations of Ca and P in whole body were affected by available Zn levels in diets. Contents of Zn and Mn in whole body also changed significantly in each experimental group during 12 weeks feeding, being affected by deletion of these metals from the mineral mixture in diets. The results of this study have demonstrated that the mineral composition in whole body of rainbow trout changed markedly over the 12 weeks period from swim up fry to fingerlings, especially after receiving diets, and then became stable between 12th and 40th week.View full abstractDownload PDF (421K) -
Shuichi Satoh, Toshio Takeuchi, Takeshi Watanabe1987 Volume 53 Issue 2 Pages 281-286
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe effect of deletion of various trace elements from the mineral mixture in the fish meal diets on mineral composition of gonads was examined by feeding fingerling of both rainbow trout and carp with various diets for 93 and 83 weeks, respectively. Deletion of one of each trace element or total deletion of trace metals from the mineral mixture in fish meal diets greatly affected the mineral compositions of both ovary and testis in rainbow trout and carp. Especially mineral compositions in gonads were found to be significantly affected by Zn or Mn deletion. The content of Zn in both testis and ovary of carp was three to four times higher than that of the rainbow trout. A similar result of Zn was also obtained in the concentration of Mn in testis, being higher in carp than in rainbow trout. However, the content of Mn in ovary of carp was much less that of rainbow trout. Thus, it is suggested that quality of eggs in terms of rate of eyed eggs and hatchability is affected by mineral status in broodstock and eggs through diets.
These results have also demonstrated that although white fish meal containing various kinds of minerals is used as a protein source, a supplement of dietary trace elements is essential for normal growth and reproduction of both rainbow trout and carp.View full abstractDownload PDF (423K) -
Haruo Sugita, Mikio Tsunohara, Michikazu Fukumoto, Yoshiaki Deguchi1987 Volume 53 Issue 2 Pages 287-290
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn order to determine the feasibility of the examination of fecat pellets hanging on the anus offish to determine the microflora of the intestine, the microflora of fecal pellets of goldfish andtilapia was compared with that of their intestinal contents. There were no significant differences inthe viable counts of the major components of bacteria between the two specimens from the samefish although the minor bacteria were not necessarily detected in both specimens. These resultsshow that the fecal pellets hanging on the fish are useful specimens to determine the intestinal microflora of the fish, and that serial sampling is possible in the same individual by this method.View full abstractDownload PDF (343K) -
Omar Shaban, Yoshihiro Ochiai, Shugo Watabe, Kanehisa Hashimoto1987 Volume 53 Issue 2 Pages 291-296
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSKuruma prawn Penaeus japonicus was kept frozen at -20°, -30°, -40°, -50°, -60° and -80°C for 9 months or stored in ice for one week. At due time intervals, the muscle was an-alyzed for changes in various parameters such as water holding capacity, tyrosine content, protein composition, etc.
During frozen storage at -20° and -30°C, expressible drip increased from 22% at the start to 41% after 9 months, and tyrosine content from 5mg/100g at the start to 15mg/100g after 7 months. The pH of muscle showed a little increase. In contrast, all the parameters did not change significantly at or below -40°C.
Muscle protein composition remained roughly constant during frozen storage up to 9 months irrespective of temperatures adopted; 48-63% myofibrillar, 29-36% sarcoplasmic, and 2-12% alkali-soluble plus stroma proteins.
One-week ice storage gave results similar to those obtained during frozen storage at -20° and -30°C. The pH of muscle increased sharply from 7.0 at the start to around 7.9 after one week.
From these results, it was concluded that -40°C is reasonable to keep the quality unchanged for a long-term storage, though -20°C is low enough for a short-term storage up to a few months.View full abstractDownload PDF (1303K) -
Nazrul MD. Islam, Hiroshi Oda, Terushige Motohiro1987 Volume 53 Issue 2 Pages 297-303
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSClupeine sulfate, a fish protamine is shown to significantly alter the morphology of washed cells of Bacillus subtilis, Shaking incubation with protamine resulted in the lysis of the cells. Electron microscopy with the thin sections of protamine treated cells revealed that protamine causes great damage to the cell-wall particularly to the outer layer of the wall. Protamine is adsorbed in fairly large amounts by isolated cell-wall, The observed pattern of uptake, measured under different pH indicates that uptake involves firm but reversible adsorption to the ionized sites on the cell, Protamine produces rapid and marked damage to cell membranes of B. subtilis causing leakage of 260nm absorbing material, inorganic phosphate and pentose from the washed cells. An optimum concentration of protamine is necessary to cause maximum leakage of cellular material. Investigations indicate that membrane damage caused by bactericidal concentration of protamine is irreversible. It is concluded that the action of polycationic protamine resembles with the action of some surface active cationic agents and polypeptide antibiotics.View full abstractDownload PDF (2670K) -
Michiko Kono, Takashi Matsui, Chiaki Shimizu1987 Volume 53 Issue 2 Pages 305-310
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThis study was conducted to examine the role of chitin-decomposing bacteria on the digestion of chitin in cultured fishes. Chitin-decomposing bacterial counts in the digestive tract contents of red sea bream and Japanese eel fed 0 and 20% chitin supplemented diet were recorded in both diet groups as 102-105 CFU per g and 104-107 CFU per g, respectively. The values were not elevated when chitin was supplemented to the diet. While the bacterial counts in the digestive tract contents of red sea bream decreased extremely when fed diets had two types of antibiotics added to them, the chitinase activities in the tissues of digestive tracts were not changed. Optimum pH of bacterial chitinases isolated from the stomach and intestinal contents of red sea bream were shown to be 6.9 and 7.1, respectively. These values were different from that of chitinase purified from stomach tissue of red sea bream as defined to be 5.5. These results suggest that there may be two types of chitinases which are of bacterial and non-bacterial origins which are involved with digestion in cultured fishes and that the latter plays a more important part.View full abstractDownload PDF (704K) -
Mampei Suzuki, Takashi Horii, Ryo Kikuchi, Toshio Ohnishi1987 Volume 53 Issue 2 Pages 311-317
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSA purified laminarinase preparation was obtained from the Antarctic krill Euphusia superba through successive chromatographies on DEAE-Sephadex A25, Sephadex G200, Sephadex G100, and DEAE-Sephadex A50. A purified laminarinase preparation showed a single protein band on disc electrophoresis. Its molecular weight was estimated to be 65, 000-70, 000. The optimum pH of this enzyme was between 4.3-5.0 and this enzyme was stable until 45°C on heating for 10min at pH 5.0. This enzyme hydrolyzed laminaran and laminarioligosaccharides except laminari-biose. The activity was inhibited by Hg2+, N-bromosuccinimide and gluconolactone.
The amounts of reducing sugars produced from laminaran at the initial stages of the reaction with this enzyme considerably surpassed the amounts of liberated glucose. The rate of hydrolysis on the periodate-oxidized and reduced laminaran by this enzyme was comparable to that on un-treated laminaran, This enzyme split laminaran into yield glucose and laminarioligosaccharides. These results indicate that this enzyme is endo-type.View full abstractDownload PDF (1421K) -
Hiroshi Yabu, Kuniyoshi Maru1987 Volume 53 Issue 2 Pages 319
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSDownload PDF (849K) -
Seinen Chow, Shigehiro Abe, Yasuhiro Ueno, Masaru Torisawa, Yoshihisa ...1987 Volume 53 Issue 2 Pages 321
Published: 1987
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSDownload PDF (869K)
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