The factors affecting the germination of spores of alkalophilic Bacillus species have been studied. The optimum pH for germination of spores of alkalophilic Bacillus No. 2b-2 was about 10 and NaCl (Na⁺) stimulated germination considerably. The optimum concentration of NaCl for germination was about 0.2M. Other cations such as K⁺, NH₄⁺, Rb⁺, Cs⁺ and Ca²⁺ did not stimulate germination. Li⁺ showed a weak activity for stimulating germination. Na+ ions stimulated the early step of germination. It was necessary for Na⁺ ions to co-exsist with the germinants in the germination of spores and the effect of Na⁺ was reversible. The same results were obtained for the germination of alkalophilic Bacillus No. 16-2 and No. 20.

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Fourteen kinds of amylase inhibitor (AI) were obtained by active carbon column chromatography and other procedures. The molecular weights of the AIs were estimated to be 310-1300 by gel filtration. They seem to have 1-4 glucose residues and one nitrogen per molecule. All the AIs have almost the same inhibitory activity against glucoamylase. High molecular weight AIs have much stronger activity toward α-amylase and phosphorylase α than low molecular weight AIs, but the latter have much stronger inhibitory activity toward sucrase and α-glucosidase than the former. Four kinds of AI were hydrolyzed by β-amylase which changed their inhibitory activities.

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Cell walls of alkalophilic Bacillus No. C-125 and No. A-59 which grew in different pH conditions were prepared and analyzed. In the walls from cells grown at pH 10.3 (pH 10.3-cell wall) and the walls from cells grown at pH 7.5 (pH 7.5-cell wall) of the alkalophilic bacilli, the contents of neutral sugar and phosphorus were low as compared with those of Bacillus subtilis 6160, while uronic acid and amino acids were abundant. The uronic acid content of the pH 10.3-cell walls was higher than that of the pH 7.5-cell walls in both strains. The insoluble fraction (peptidoglycan) of cell walls of Bacillus No. C-125 consisted of muramic acid, glutamic acid, alanine, diaminopimelic acid and glucosamine as in neutrophilic bacilli. In the TCA soluble fraction of pH 10.3-cell walls of Bacillus No. C-125, uronic acid was a polymer of glucuronic acid containing a small amount of hexosamine, and 2/3 of the ninhydrin positive material was glutamic acid which was derived mainly from poly γ-L-glutamic acid.

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A Perigo-type antibacterial factor (PTF) was produced when tryptone (a pancreatic digest of casein) medium was heated with nitrite at 121°C for 20 min. This PTF was inhibitory against Staphylococcus aureus, Bacillus subtilis and Clostridium botulinum, but was not against Escherichia coli and Salmonella typhimurium. The inhibitory activity varied with the concentration of nitrite (5-100 ppm) and tryptone (1, 2, 4%), and with pH (4, 5, 6, 7). The maximum inhibitory activity was observed when the medium containing 4% tryptone and 0.2% thioglycolate was heated with more than 50 ppm nitrite at pH 6. The tryptone was separated into three fractions by gel filtration and PTF was produced in every fraction, although the inhibitory activity was different in each. Our PTF might be unstable towards oxygen because its activity was lost completely by shaking for more than 16 hr.

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Bluish fluorescent and phenolic components were produced in cassava roots in response to cutinjury, and in relation to physiological deterioration and microbial deterioration. The former proved to consist of five coumarin components, the main three of which were scopoletin, scopolin and esculin, and the other two were scopoletin- and esculetin-containing conjugates. A main component of the latter was (+)-catechin. Some enzymes pertaining to the production of the secondary metabolites such as acid invertase, phenylalanine ammonia lyase and peroxidase were formed in cut-injured tissue and in non-infected tissue adjacent to the soft-rotten part.

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Some phosphorus derivatives of oxadiazoles were synthesized to seek insecticidal lead compounds. The 1, 3, 4-oxadiazol-2-ones were converted via the N-methylol derivatives to the corresponding N-chloromethyl derivatives. From these derivatives a variety of 0, 0-dimethyl phosphorodithioates 4, 0, 0-dimethyl phosphorothioates 5 and 0, 0-di-i-propyl phosphorothioates 6 were prepared.
These phosphorus derivatives were examined for insecticidal activity towards houseflies and for anti-acetylcholinesterase (anti-AChE) activity using the housefly heads as an enzyme source. Most of the compounds 4 and 5 showed contact toxicity as high as the analogous methidathion insecticides, which appeared to correlate with the strong anti-AChE activity. On the other hand, all the compounds 6 showed a high activity in AchE inhibition but only a poor insecticidal activity.

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An acid α-glucosidase was purified from pig liver by fractionation with ammonium sulfate, chromatographies on DEAE-Sepharose, Sephadex G-100 and Bio-Gel P-150, and preparative disc electrophoresis. The molecular weight was estimated to be 1 × 10⁵ by sodium dodecylsulfate-disc electrophoresis. The optimum pH was found to be 4.5. The α-glucosidase showed a high activity not only toward maltose but also toward α-glucans, soluble starch, glycogen, amylopectin, β-limit dextrin and amylose. The Km values for maltose and glycogen were 6.7mM and 10mg/ml, respectively, and the ratio of maximum velocities of hydrolysis of the two substrates was 100:71.3, in that order.
The purified enzyme from pig liver was a typical acid α-glucosidase of mammalian origin.

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The substrate specificity of pig liver acid α-glucosidase was investigated. The enzyme showed a wide specificity on various substrates. The Km values for maltose, malto-triose, -tetraose, -pentaose, -hexaose and -heptaose, and maltodextrin (mean degree of polymerization, 13) were 6.7mM, 4.4mM, 5.9mM, 11mM, 4.0mM, 5.6mM and 7.1mM, respectively. The relative maximum velocities for maltooligosaccharides consisting of three or more glucose units were 82.6 to 92.3% of the maximum velocity for maltose. For disaccharides, the rates of hydrolysis decreased in the following order : maltose > nigerose > kojibiose > isomaltose. The acid α-glucosidase also hydrolyzed several α-glucans, such as glycogen, soluble starch, β-limit dextrin and amylopectin. The Km value for β-limit dextrin was the lowest of those for α-glucans.
The nature of the active site catalyzing the hydrolyses of maltose and glycogen was investigated by kinetic methods. In experiments with mixed substrates, maltose and glycogen, the kinetic features agreed very closely with those theoretically predicted for a single active site catalyzing the hydrolyses of both substrates. Cations, Na⁺, K⁺ and Mg^{+ +}, were about equally effective in the activation of the enzyme action on maltose and glycogen. The inhibitor constants of tris (hydroxymethyl) aminomethane (Tris) and turanose were nearly the same for maltase activity as those for glucoamylase activity. From these results, the enzyme was concluded to attack maltose and glycogen by a single active site mechanism.

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The irradiation effect on components of a commercial fish meal and their storage effect were investigated. The numbers of contaminating microorganisms in the fish meal were as follows : total aerobic bacteria, 3.5×10⁵ ; coliforms, 1.4×10³ ; osmophilic moulds, 4.8×10² ; and fungi, 2.8×10² per gram. The osmophilic moulds, fungi and coliforms could be eliminated below their identification limit at 0.2, 0.3 and 0.5 Mrad, respectively, while the number of total aerobic bacteria could not be eliminated even at 1.0 Mrad. The crude protein content, pepsin digestibility, amino acid compositions and crude lipid content were not changed by irradiation up to 5.0 Mrad, while acid value and peroxide value were slightly increased. The increase in peroxide value by irradiation was depressed in the deoxyganated condition.
The number of osmophilic moulds in unirradiated fish meal, in which the moisture content was adjusted to 15.5%, increased during storage at 30°C. The number of moulds increased after 1 month storage of the 0.5 Mrad irradiated sample but the occurrence of the moulds was inhibited in the 1.0 Mrad irradiated sample during 2 months storage. The crude protein content and pepsin digestibility were unchanged during storage in both the irradiated and unirradiated samples, while the acid values increased. As the number of moulds increased, the moisture content and peroxide value increased, with the crude lipid content decreasing markedly during storage of the unirradiated samples. On the other hand, changes in irradiated samples could be controlled during storage.

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Volatile flavor compounds of boiled buckwheat flour were collected using a Likens and Nickerson apparatus type and were fractionated into acidic, weak acidic, basic and neutral fractions. The neutral fraction was further fractionated by silica gel column chromatography. All fractions were analyzed by gas chromatography and gas chromatography-mass spectrometry.
Two hundred and nine compounds were thus identified. Among them, 168 were newly identified as volatile flavor compounds of buckwheat flour ; special note is made of 2-(1'-ethoxyethyl)pyrazine and 2-(1'-ethoxyethyl)-5-methylpyrazine being found which are compounds previously unreported in any literature.

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As a result of screening for Dragendorff-positive substances of fungal origin, from wheat bran cultures, 2 new metabolites named nigerazine B (I) and A (II) were isolated from Asp. niger I-639. The structure of the main component, nigerazine B, was determined to be N-methyl-trans-2, 5-dimethyl-N'-cinnamoyl-piperazine from the physicochemical data and confirmed by synthesis. It was inactive against the microorganisms tested, but exhibited some inhibitory activity toward the root growth of lettuce seedlings.

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The heat-treated acid precipitated proteins (H-APP), as intermediates in the commercial, production of isolated proteins from defatted soybeans, were dispersed under an ultrasonic power field over a protein concentration range from 5.4 to 12.6%.
The ultrasonically untreated H-APP dispersions showed a pseudoplastic flow behavior, which was characterized by shear rate thinning, giving a yield value above 9.0%. With prolongation of the ultrasonic exposure duration, a rapid decrease in the apparent viscosity of resultant dispersions was observed under the condition of 200W/100g, with a rapid increase in flow behavior index according to the power law. In addition, ultrasonication induced the rise in critical concentration for the yield value up to 12.6%. As a result, the flow of 120 sec-irradiated dispersions became almost Newtonian at a concentration of 5.4-9.0%, but remained pseudoplastic above this range.
The result obtained from gel filtration revealed that these changes in flow properties are derived from a dissociation of the protein aggregates which have formed through heat treatment of the APP prior to ultrasonication. Furthermore, the ultrasonic-induced structural alteration was considered to be associated with a partial cleavage of intermolecular hydrophobic interactions rather than with peptide-, or disulfide-bonds.
Mechanical treatment such as ultrasonication is considered to be practically applicable in the production of soy protein foods, providing a significant improvement in the efficiency of unit processes such as pumping, piping, and spray drying, due to its ability to modify the flow properties of protein dispersions.

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The solubility characteristics of isolated soy protein (ISP) in high ionic environments were measured in accordance with an NSI (nitrogen solubility index) method in order to study the effect of the thermal process in its commercial production. When the acid precipitated protein (APP) dispersions were heated to above 60°C and subsequently spray dried, the solubility of the resultant ISP in 0.5 M (molar) NaCl was lowered with increasing temperature, ranging from 91% at 60°C to 43% at 90°C, while the solubility in H₂O remained at almost the 100% level regardless of heating condition. Solubility changes in 90°C-heated ISP in various 0.5m (molal) salt solutions indicated that salting-out of this protein preparation can be represented as a function of molal surface tension increment of the salt used ; the solubility of ISP in ionic environments can be determined by its hydrophobicity, which seems to increase with a rise in the heat treatment temperature of APP. Therefore, there was a significant difference in salting-out behavior depending upon the order of addition of ingredients to the system ; when salt was added to the slurry after the ISP was thoroughly rehydrated, no salting-out was observed in 0.5m ionic environments. Ultrasonication of 90C-heated APP prior to spray drying was tested to examine the possibility of improving the solubility profiles of resultant ISP, with the result that a remarkable increase of solubility in 0.5 M NaCl was attained. The effect of such ultrasonication was probably due to its ability to increase the hydrophilic nature of proteins.

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Quinoxalines derived from various homoglucans by the alkaline OPD method were subjected to GLC and GC-MS analyses.
The main quinoxalines derived from amylose and curdlan were identified as 2-hydroxymethyl-3-(2', 3'-dihydroxypropyl) quinoxaline (M- 1) and 2-(2', 3', 4'-trihydroxybutyl) quinoxaline (G-1), respectively, using a 2% OV-210 column after trimethylsilylation. Two quinoxalines M-1 and G-1 were formed from barley glucan and lichenan, and the approximate molar ratios of the 1, 4- to 1, 3-linkage in both glucans were estimated to be 1.6 and 2.2, respectively. From scleroglucan, G-1 and 2-(2', 3'-dihydroxy-4'-D-glucopyranosyl) quinoxaline were produced, reflecting a 1, 3- and branched 1, 6-linkage in the glucan. The ratios of the 1, 4- to 1, 3-linkage of barley glucan and lichenan, or the 1, 6- to 1, 3-linkage of scleroglucan estimated from the formed quinoxalines were in accordance with those obtained by conventional methylation analysis.

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Quinoxalines derived from D-xylose and o-phenylenediamine (OPD) in an acidic medium under reflux were studied, using GLC, GC-MS and NMR measurements.
Three quinoxaline derivatives (XA-I, XA-II and G-2) were separated from the reaction mixture of D-xylose with OPD (0.2 mol, each) in a 46% total yield. Their approximate molar ratio was 3:3:2. Two newly isolated XA-I and XA-II derivatives were identified as 2-methyl-3-(2'-hydroxyethyl) quinoxaline and 2-(1', 2', 3'-trihydroxypropyl) quinoxaline, respectively. The other was G-2 [2-(2', 3'-dihydroxypropyl) quinoxaline], which has previously been obtained from D-glucose or D-xylose in an alkaline solution. XA-I may be regarded as a partially reduced form of G-2 at the side chain of the quinoxaline, with XA-II as an oxidized form. A possible mechanism for quinoxaline formation is discussed.

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Potato tubers contain 3 debranching enzymes separable by polyacrylamide gel electrophoresis. One of them, isoamylase, has been purified to apparent homogeneity on disc gel electrophoresis by isoelectric precipitation, fractionation with ammonium sulfate, gel filtration on Sepharose 6B and finally affinity chromatography on Sepharose 4B-soluble starch, successively. The purified enzyme has a specific activity of 8.0U/mg of protein. It hydrolyzes the α-1, 6-glucosidic bonds in glycogen and phytoglycogen not only as rapidly as those in amylopectin but also completely, but cannot hydrolyze pullulan. From these results potato isoamylase was found to have the same substrate specificity as that of Pseudomonas isoamylase. However, different from the latter, it has an optimum pH of 5.5-6.0, optimum temperature of 50°C and was reversibly inactivated by p-chloromercuri-benzoate.

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cis-Abienol-transformable bacterium JTS- 131 was identified as Rhodococcus erythropolis. This bacterium had a plasmid, pCA4. Cured strains which had no plasmid were obtained by mitomycin C treatment. These cured strains lost the ability to oxidize the C-18 methyl of cis-abienol and sclareol. From these results, it was considered that C-18 methyl oxidation of these labdanes was determined by the plasmid, pCA4, in this bacterium.

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Rhodococcus erythropolis JTS-131, a cis-abienol and sclareol transformable bacterium, converted manool and accumulated manoyl oxide in the culture broth. In the presence of metabolic inhibitors, 13β-hydroxylabda-8(17), 14-dien-18-oic acid and its methylester (a new compound) were accumulated as the transformation products. This strain also transformed (12Z)-labda-8(17), 12, 14-triene and accumulated (12Z)-labda-8(17), 12, 14-trien-18-al in the culture broth. In the presence of metabolic inhibitors, two compounds, (12Z)-labda-8(17), 12, 14-trien-18-ol and 4, 18, 19-trinor-3, 4-seco-5-oxo-(12Z)-labda-8(17), 12, 14-trien-3-oic acid were accumulated. Based on the experiments on the degradation sequence, transformation pathways for these two labdanes by the bacterium are proposed.

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(R)-(-)-10-Methyl-2-tridecanone, the pheromone of Diabrotica undecimpunctata howardi Barber, was synthesized from (R)-(+)-citronellyl acetate.

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The optically active monocyclic β-lactams 1 were synthesized from L-aspartic acid α-benzyl ester by the four-component-condensation method. The conversion of the amides 1 to the corresponding methyl esters 2 were accomplished via imino chlorides. The tricyclic β-lactam 4 and 5 were prepared by intramolecular Friedel-Crafts acylation, whose ketone groups were reduced to the methylene analogues 8 and 10, respectively. Further transformation of the furan derivative 10a to a bicyclic 1-carbacephem compound 12 by oxidative ring cleavage was also investigated.

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Growing rats with silver loading (250μg/g diet as silver acetate) were examined for silver and selenium contents and glutathione peroxidase activities in various tissues. Silver was found at a much higher level in the livers than in the kidneys. Silver loading for 4 weeks caused a decrease in the selenium contents and glutathione peroxidase activities in the tissues without affecting rat growth. Since addition of silver to the diet led to a few-fold increase in fecal selenium excretion, the decreased selenium availability in silver-loaded rats was considered to arise from obstruction of selenium uptake in the intestine. In another experiment, selenite, selenomethionine and selenocystine were administered via intraperitoneal injection (50μg/kg once a day for 7 days) to rats previously given silver for 3 weeks. The glutathione peroxidase activities in the livers and kidneys were markedly elevated by the selenium administration, although they were inferior to those in rats not receiving silver. The selenium availability in silver-loaded rats varied with the chemical form of selenium and was to a lesser extent in the case of selenite administration. On the other hand, a significant difference was observed between the rats with and without silver loading regarding the selenium contents in the 105, 000×g pellets of liver and kidney homogenates. The accumulation of selenium there was accompanied by that of silver of about ten or a hundred times as much as selenium in concentration (μg/g tissue). Such excess silver accumulation may be explained with the assumption that silver ions undergo reduction by selenite or selenocysteine, but not by selenomethionine, to accumulate as non-charged silver metal within the cells.

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The effect of β-ovomucin on the solubility of α-ovomucin was studied in the presence or absence of lysozyme. The α-ovomucin content in a mixed solution of α-ovomucinwas calculated with a simultaneous equation devised on the basis of the differences in the protein and carbohydrate contents of the two ovomucin.
β-Ovomucin inhibited the formation of α-ovomucin aggregates in a salt-free solution or in a slightly acid one. α-Ovomucin formed an insoluble complex with lysozyme below pH 10 at the ionic strength of 0.01, and β-ovomucin formed an insoluble complex with lysozyme below pH 6. β-Ovomucin inhibited the formation of an insoluble α-ovomucin complex with lysozyme in neutral or slightly alkaline pH regions.
It was presumed that bound β-ovomucin inhibits the aggregation of the α-ovomucin-lysozyme complex in thick egg white and results in the formation of a gel structure.

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Studies were initiated to examine the formation of urea and/or ammonia from arginine and some other amino acids, and the metabolism of arginine, citrulline, ornithine, and proline in a starved rumen ciliate protozoal suspension. Not urea but ammonia was produced from arginine and also from citrulline, ornithine, aspargine and glutamine of the 10 amino acids tested. Urea was not hydrolysed. Using labeled compounds, citrulline was paper- and column-chromatographically identified as the first intermediate in arginine metabolism. Citrulline, ornithine and proline were converted to ornithine, proline and δ-aminovalerate (DAV), respectively. DAV underwent no more degradation. The ability to reduce proline to DAV decreased with the incubation time for preparing the starved ciliate suspension. Appreciable amounts of arginine and arginine with citrulline were synthesized from citrulline and ornithine, respectively.

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Aziridinylphosphinothionates were prepared from optically active ethyl hydrogen phenylphosphonothionates and 1-bromo-2-alkanamines derived from leucine or valine. The aziridine ring was opened by the action of some nucleophiles. Refluxing the aziridinylphosphinothionates in acetone with sodium iodide caused hydrolysis accompanied by the rearrangement of the sulfur atom to give β-mercaptoethylphosphonamidates. The reaction mechanism was discussed with stereochemical considerations. The insecticidal activity of the products was also examined.

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In the presence of an alkaline ion-exchange resin (Amberlite IRA-410), 2-acetamido-2-deoxy-5, 6-O-isopropylidene-3-O-methyl- and -3-O-(tetrahydropyran-2-yl)-D-glucofuranoses, and 2-acetamido-2-deoxy-5, 6-O-isopropylidene-D-allofuranose, as well as 2-acetamido-2-deoxy-5, 6-O-isopropylidene-D-glucofuranose were converted into 2-acetamido-2, 3-dideoxy-5, 6-O-isopropylidene-α-D-erythro-hex-2-enofuranose. The β-elimination was also observed in the case of 2, 5-diacetamido-2, 5-dideoxy-D-xylo- and -D-ribo-furanoses, to give 2, 5-diacetamido-2, 3, 5-trideoxy-D-glycero-pent-2-enofuranose. C-3-Deoxy-furanoses, such as 2-acetamido-2, 3-dideoxy-5, 6-O-isopropylidene-D-arabino- and -D-ribo-hexofuranoses, and 2, 3, 5-triacetamido-2, 3, 5-trideoxy-Dribofuranose, however, did not give β-eliminated compounds under the same condition.

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A variety of N-(acyl)muramoyl-dipeptides were synthesized and their immunoadjuvant activities were examined on the induction of delayed-type hypersensitivity to N-acetyl-L-tyrosine-3-azobenzene-4'-arsonate in guinea pigs. It was found that introduction of acyl groups to the 2-amino group in muramoyl-L-valyl- or -L-seryl-D-isoglutamine reduced the activity with the increasing length of the acyl group, although all N-(acyl)muramoyl-L-alanyl-D-isoglutamines were active as an adjuvant. The results suggest that development of the adjuvant activity of N-(acyl)muramoyldipeptides is closely related to both the length of the acyl group and the bulkiness of the peptide moiety.

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The odor-producing volatiles produced by electron beam irradiation for the sterilization of polyethylene film were examined and identified using gas chromatography and gas chromatography-mass spectrometry. The main volatile products in low density polyethylene irradiated with an. electron beam were aliphatic hydrocarbons, aldehydes, ketones, and carboxylic acids. Aliphatic hydrocarbons accounted for ca. 35% of the total peak area, and saturated hydrocarbons up to C₁₃ were predominant. Four aldehydes with C₂ to C₅ carbon atoms, six ketones with C₄ to C₈, and five carboxylic acids with C₂ to C₅ were detected. Aldehydes and ketones accounted for ca. 26% of the all volatiles, and carboxylic acids for ca. 18%. Small amounts of alcohols, toluene, and phenol were also found. In a sensory test of the odor from the mixed solution of identified compounds, the odor was found to resemble the off-odor of the irradiated polyethylene.

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3-Chloro-D-alanine chloride-lyase, which occurs in the cells of Pseudomonas putida CR 1-1, catalyzes the β-replacement reaction of 3-chloro-D-alanine in the presence of a high concentration of sodium hydrosulfide to form D-cysteine. Using the β-replacement reaction, the synthesis of D-cysteine from a racemate of 3-chloroalanine by resting cells was investigated. In order to depress the synthesis of L-cysteine from 3-chloro-L-alanine and the enzymatic degradation of 3-chloro-L-alanine, treatment of the cells with 5mM phenylhydrazine was utilized. Under the optimal conditions, 94% of the added 3-chloro-D-alanine could be converted to D-cysteine and 81% of the added 3-chloro-L-alanine was recovered.

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Seven optically active analogues which were (4S)-, (8S)- and (4R)-analogues of the aggregation pheromone of the red flour beetle, Tribolium castaneum, were stereoselectively synthesized from optically pure (R)-(+)-citronellic acid (100% e.e.) and/or (S)-(-)-2-methyl-l-butanol (93% e.e.) to elucidate the structure-activity relationship of the pheromone. The (8S)-configuration was derived from (S)-(-)-2-methyl-1-butanol, and the (4S)- or (4R)-configuration was from (R)-(+)-citronellic acid.

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A plasmid, YRp7, carrying the yeast TRP1 gene transformed a trpl strain JH of Saccharomyces cerevisiae without spheroplasting. The transformation conditions were that intact cells were incubated with the plasmid DNA in chilled CaCl₂ solution and then the incubation temperature was raised. The transformation frequency changed markedly with the CaCl₂ concentration of the solution and the temperature rise after incubation at 0°. The optimal CaCl₂ concentration and temperature for strain JH were 200 mM and 37°, respectively. Polyethylene glycol and the age of cells showed little effect on the transformation. The highest transformation frequency obtained was 300 colonies per μg plasmid DNA, and this was comparable to that obtained with the JH strain by the conventional method using spheroplasts. Transformation was confirmed genetically.

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Male Sprague-Dawley rats were fed diets containing linseed oil, safflower oil, or cacao butter for 27 weeks. The collagen-induced aggregation of washed platelets decreased only in rats fed linseed oil. Dietary oils did not influence the phospholipid composition of platelets, but did influence the fatty acid composition of platelet phospholipids. Compared with the other diets, the linseed oil diet markedly decreased the arachidonic acid content in platelet phosphatidylcholine and accumulated the eicosapentaenoic acid in all phospholipids. A similar change was not found in platelets from rats fed the other diets. These results indicate that the feeding of linseed oil, which has a high linolenic acid (a precursor of eicosapentaenoic acid) content, alters the fatty acid composition of platelet phospholipids similar to the feeding of fish oils, and thereby reduces the aggregation tendency of platelets.

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An in vitro DNA replication system having a high specific activity could be prepared as a clear solution from isolated nuclei of Saccharomyces cerevisiae as described below. The isolated nuclei were treated with 0.4% Nonidet P-40 and precipitated by centrifugation in 20% sucrose. From the precipitate thus obtained, DNA-replicating activity was extracted with 0.5 m KC1. The extract has the ability to incorporate ³H-dTMP into the acid-insoluble fraction (DNA)in the presence of a template DNA, such as pJDB 219 or YRp 7. After 10 min incorporation reaction, in the template DNA, formation of a "replication eye" could be demonstrated under an electron microscope. The sum of the lengths of the eyes was found to be equivalent to the amount of the synthesized DNA calculated from incorporated ³H-dTMP.The specific activity (4.9 nmol dTMP incorporation/mg protein of solubilized fraction/60 min, at 28°C) of the DNA-replicating reaction measured with the present system was approximately 60-fold higher than the highest one previously reported.^{1, 2)}

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