Many kinds of salts were antioxidative on the autoxidation of linoleic acid (LA) and linoleic acid hydroperoxide (LAHPO). These effects of salts were the most remarkable at 1M of them. The effect of KI was the strongest among tested salts. LA in KI solution did not absorb any oxygen, and LAHPO in that solution consumed 1/7 of absorbed oxygen by LAHPO in KI free solution, even by additional supply of FeSO₄. One mole of LA and LAHPO purified from the above oxidizing mixture consumed 1.76 and 0.78 mole of oxygen, respectively. Besides, the addition I^- to LA was not observed by analysis with GLC-MS. Then, LA and KI mixture in methanol was excited with 315 nm wavelength, and the fluorescence peak was observed at 412 nm. Intensity of this peak depended on the concentration of LA. These results supported the possible antioxidation mechanism of KI on the autoxidizing LA involving the complex formed between LA and KI in the solution.

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Dextransucrase (EC. 2. 4. 1. 5) of Leuconostoc mesenteroides was purified from the culture filtrate by precipitation with solid ammonium sulfate in the presence of egg white albumin followed by successively treating with columns of DEAE-cellulose and Bio Gel P-150.
The purified enzyme lost the activity upon dialysis against EDTA, and was reactivated by the addition of alkaline arth metal ions. The best reactivation was brought about by calcium ion. The enzyme inactivated by EDTA was unstable and readily denatured irreversity. Several other properties of the purified enzyme were also investigated and discussed.

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Two auxotrophic mutants of Corynebacterium glutamicum were found to produce a large amount of L-proline in the culture medium. High concentration of MgSO₄ or MnSO₄ in the medium stimulated the L-proline production by an isoleucine auxotroph. Optimum concentration of L-isoleucine was 200 μg/ml, and the higher concentration of L-isoleucine reduced the L-proline production. The auxotroph produced 14.8mg/ml of L-proline when cultured in a medium containing 12% glucose, 1.7% NH₄Cl, 0.6% MnSO₄•7H₂O, 0.06% MnSO₄•4H₂O and 200 μg/ml of L-isoleucine. The other mutant, whose growth responds to the bases of nucleic acids, produced 7 to 13mg/ml of L-proline in a cane molasses (15%, as glucose concentration)-medium containing 2% of the acid-hydrolyzate of soybean meal. The L-proline production by this mutant increased to a level of 27 to 31mg/ml when the growth was suppressed by the addition of 4% NH₄Cl to the medium, or by the addition of 2mg/ml of polyoxy-ethylenestearylamine, a surfactant, to a culture at an appropriate stage of the fermentation.

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The spoilage rates of unirradiated and irradiated (0.1 Mrad) Bombay duck (Harpodon nehereus) homogenates stored at 0°C, 10°C and 30°C in terms of organoleptic score (OS) total bacterial count (TBC), trimethylamine content (TMA), and total volatile basic nitrogen (TVBN) followed a linear response with increase in temperature. Unirradiated Bombay duck stored at 0°C were found to spoil faster than those irradiated at 0.1 Mrad; the spoilage rates derived for TBC, TMA, TVBN and OS were 0.42, 0.67, 1.93 and -0.86 respectively for unirradiated samples as compared with corresponding values of 0.31, 0.55, 1.19 and -0.19 for the irradiated samples. The spoilage rates of unirradiated Bombay duck stored at 10°C and 30°C measured as a function of OS, TMA and TVBN were consistently higher than their irradiated (0.1 Mrad) counterparts. In the case of irradiated samples, TBC was not a satisfactory index of spoilage.

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The plastein formation by α-chymotrypsin from an ovalbumin hydrolysate was affected in an order of valency of salts when the concentration of each salt was 1M. Monovalent cations were rather effective at this concentration and enhanced the plastein yield by 10%. In the presence of NaCl, the plastein formation showed two distinct maximal rates at its concentrations of 0.1M and 0.8M. The first maximum was considered to be resulted from an increase in enzyme activity, since chymotryptic hydrolysis of both N-acetyl-L-tyrosine ethyl ester and benzyloxycarbonyl-L-phenylalanine p-nitrophenyl ester was activated at an NaCl concentration of 0.1_??_0.2M. The second maximum was ascribed to the salting-out of the product due to the higher concentration of NaCl. A salt-tolerant protease was also used to confirm the above conclusions. It was observed that this enzyme was much effective in producing a plastein at a high NaCl concentration. This may be due to the fact that both the enzyme activation effect and the product salting-out effect participate co-operatively.

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Acid carboxypeptidase of Penicillium janthinellum IFO-8070 was produced effectively in submerged culture on a medium of 4_??_5% rice bran. The enzyme production was enlarged to volume cultivation of 150-liters in a 200-liters jar fermentor, and the yield of acid carboxy-peptidase per milliliter filtrate reached to the maximum 3 days after inoculation.
Acid carboxypeptidase of low molecular weight (M. W.=51, 000) produced in the liquid culture broth was purified and crystallized in a large scale. Purification steps include Amberlite CG-50 treatment, ammonium sulfate precipitation, dialysis using “Diaflow, ” activated charcoal treatment, and condensation using collodion-bag, or condensation and dialysis using “Diaflow.”
The crystals of the acid carboxypeptidase suspended in 50mM acetate buffer (pH 3.7) were completely stable for six months at 5°C. On the other hand, at low enzyme concentration (0.01 U/ml) in 50mM acetate buffer (pH 3.7), crystallized enzyme was somewhat labile, whereas, this inactivation was completely depressed by covering enzyme solution with toluene.

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A microorganism, strain KI 72 capable of utilizing ε-aminocaproic acid cyclic dimer as sole carbon and nitrogen sources was isolated from sludge and identified as Achromobacter guttatus. This bacteria utilized 1% of the cyclic dimer in a day and was not inhibited by the higher concentration of the dimer. The growth rate was independent of the cyclic dimer concentration in the medium, but the maximum cell concentration increased with the increase of substrate concentration. The cell yield was 0.7mg dry cell/mg ε-aminocaproic acid cyclic dimer. Bacterial growth with the cyclic dimer as substrate was significantly stimulated by the addition of yeast extract. Ferric chloride was also stimulatory. Maximal growth was obtained in cultures incubated at pH 6 and at 33°C. Synthesized nylon oligomers, ranging from ε-aminocaproic acid up to its linear hexamer, were found to be catabolized by this organism.

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Microorganisms were tested for production of cephalosporin acylase. Some bacteria showed strong acylase activity for all of cephalexin, cephaloridine, cephalotin, penicillin G and ampicillin. Some showed a rather specific activity for cephalexin. Pseudomonas melanogenum KY 3987 showed specific activity only for cephalexin and ampicillin which contain a side chain of D-phenylglycine. Most of these acylase-producing bacteria had the ability to synthesize cephalexin and other cephalosporins from 7-aminocephem compounds and organic acid esters. Among them, Kluyvera citrophila KY 7844 was one of the most promising organisms for enzymatic synthesis of cephalosporins. This organism had the ability to catalyze N-acylation of 7-aminocephem compound not only with α-amino acid ester, but also with such acid esters as 1-(1-H)-tetrazolylacetate methylester which has no α-amino group.

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Feeding rats with a fat meal caused marked reduction in the level of plasma urea and urinary output of urea and total nitrogen. Experiments were carried out to examine the possible intervention of some hormones in these phenomena. Protein sparing action of fat was exerted even in the alloxan-diabetic, adrenalectomized, hypophysectomized and thyroi-dectomized rats. Feeding rats with a fat meal caused no appreciable change in the level of cyclic AMP in liver and gastrocnemius muscle. The overall results obtained here are throught to suggest that the action of fat may be exerted independently of any hormones examined; insulin, glucocorticoids, cyclic AMP and other hormones excreted from adrenal, hypophysis and thyroid gland.

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Metabolites arising from the catabolism of lysine by the mixed rumen bacteria were chromatographically examined by using radioactive lysine. After 6 hr incubation, 241 nmole/ml of lysine was decomposed to give ether-soluble substances and CO₂ by the bacteria and 90 nmole/ml of lysine was incorporated unchanged into the bacteria. δ-Aminovalerate, cadaverine or pipecolate did not seem to be produced from lysine even after incubation of the bacteria with addition of those three amino compounds to trap besides lysine and radioactive lysine. Most of the ether-soluble substances produced from radioactive lysine was volatile fatty acids (VFAs). Fractionation of VFAs revealed that the peaks of butyric and acetic acids coincided with the strong radioactive peaks. Small amounts of radioactivities were detected in propionic acid peak and a peak assumed to be caproic acid. The rumen bacteria appeared to decompose much larger amounts of lysine than the rumen ciliate protozoa did.

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A growing culture of Clostridium saccharoperbutylacetonicum partially lost its turbidity in the presence of 0.3 to 0.6M sucrose without any extraneous supplements for cell wall degradation. The maximum effect was shown at 0.35M of sucrose and the culture lost 40 to 50% of initial turbidity. The rate of lysis depended on the age of culture. The most rapid lysis occurred in the organisms of early exponential growing cultures, but no lysis was observed on those of late exponential and stationary phase cultures. The optimal pH was 5.5 to 6.0, and the optimal temperature 30 to 35°C. The sucrose-induced lysis was inhibited by bivalent cations (such as Ca²⁺, Mg²⁺), heavy metal cations (such as Cu²⁺, Pb²⁺), enzymic inhibitors (such as PCMB) and fixative agents (such as formalin, glutaraldehyde), while organisms whose growth had been inhibited by antibiotics (such as chloramphenicol, tetracycline) were also resistant to sucrose-induced lysis. The sucrose-induced lysis was accompanied by striking morphological conversion from original rod cells (3.0_??_6.0×0.4_??_0.6 μ) to spherical cells (1.0_??_1.2 μ diameter).
The sucrose-induced lysis was also observed on the relative strains of C. saccharoperbutylacetonicum and C. sporogenes, but not observed on many other species of Clostridium and aerobic bacteria tested. It was suggested that sucrose-induced lysis was a kind of bacterial autolysis which was induced by sucrose treatment. The bacterial spheres developed during the lysis may be the protoplasts.

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Chemical changes in lysozyme during heating at 150_??_250°C for 20min were investigated by means of IR, ESR, and CD spectroscopies and gel permeation chromatography, and further a tryptic hydrolysate from the lysozyme heated at 200°C was analyzed by ion exchange chromatography. At 150°C, polymerization through disulfide linkages was observed, and at 180C, both polymerization and degradation occurred. When the temperature was raised to 200°C, remarkable changes in the structure of lysozyme, such as cleavage and recombination of peptide bonds, occurred. Over 200°C, polymerization and degradation occurred more violently.

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The aroma concentrates from Vietnamese green tea and lotus tea were prepared and analyzed. Characterization of the components were carried out using coupled gas chromatography and mass spectrometry and infrared spectrometry, besides gas chromatographic retention data.
Anethole and 1, 4-dimethoxybenzene have been identified for the first time as the flavor constituents in green tea. Linalool, two linalooloxides (cis and trans, five membered), 3, 7-dimethyl-1, 5, 7-octatriene-3-ol, 2, 5 (or 2, 6)-dimethylpyrazine and 1-ethyl-2-formylpyrrole were the predominant components in Vietnamese green tea.
1, 4-Dimethoxybenzene has been identified as the main component in lotus tea. The compound was also isolated from both dried and fresh lotus pollen.

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Glutamate kinase activity was separated into two different protein fractions, i.e. glutamate kinase I and II, through the purification of twice carried out ammonium sulfate fractionation and DEAE-cellulose column chromatography, and both specific activities were raised nearly ten times higher. Each kinase was found to catalyze kinase reaction stoichiometrically. The optimum pH range of both kinases was between 7.5 and 8.0. The Km value of kinase I and II for L-glutamatic acid were 1.7×10^-2M and 3.1×10^-2M respectively. Both kinases were specific for only L-glutamic acid, and formed L-glutamine from L-glutamic acid by the addition of ammonium ion instead of NH₂OH. No effect of L-proline on either kinase was detected. L-Glutamine markedly inhibited kinase II competitively with L-glutamic acid. Kinase I catalyzes the so-called forward transfer reaction more effectively than kinase II, whereas kinase II catalyzes the reverse transfer reaction four times effectively. Kinase II seems to be more closely related to L-glutamine biosynthesis and kinase I to L-proline biosynthesis.

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In an attempt to relate structure to anticoccidial activity, a number of 5-modified analogs of 4-deoxypyridoxol (4-DOP) and α⁴-norpyridoxol have been synthesized and their biological activities examined. The compounds prepared include the 5-(3-hydroxypropyl), 5-(2-hydroxyethyl), 5-(1-hydroxyethyl), formyl and acetyl analogs of 4-DOP, and 5-(3-hydroxypropyl), formyl, ethoxycarbonyl, carbamoyl and hydroxyl analogs of α⁴-norpyridoxol. Among these compounds, 4-deoxyisopyridoxal and α⁴-norisopyridoxal were found to exhibit anticoccidal activity.

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Some analogs of α⁴-norpyridoxol in which 3-hydroxyl group is replaced by amino and substituted-amino groups have been prepared and evaluated for anticoccidal activity. 3-Aroylamino analogs of α⁴-norpyridoxol have some coccidiostatic effect towards Eimeria tenella.

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The cholinesterase of Pseudomonas aeruginosa A-16 was purified approximately 11, 150-fold with an overall recovery of 15.2% and proved to be homogeneous by electrophoresis, ultracentrifugation and chromatography. The molecular weight of the enzyme was determined as approximately 30, 000 by equilibrium centrifugation and gel filtration methods. The sedimentation coefficient, s_{20, w} was determined to be 3.3 S. Isoelectric focusing electrophoresis with carrier ampholite revealed that the enzyme had an isoelectric point around pH 8.1.
The purified cholinesterase, which was considered to be an acetylcholinesterase from its substrate specificity, hydrolyzed acetylthiocholine and acetylcholine at the highest rates among the various esters tested.
The estimated values of Km at pH 7.5 and 25°C were 1.5×10^-4M for acetylthiocholine and 1.9×10^-4M for acetylcholine. The enzyme also hydrolyzed the acetyl and propionyl esters of several aliphatic and aromatic alcohols at a lower rate which was entirely dependent on the properties of the alcohol moiety of those esters.

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Cephalosporin C negative mutants, lacking a certain step in the pathway of cephalosporin C biosynthesis, were obtained from Cephalosporium acremonium ATCC 14553 by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. Among these mutants, the strains Nos. 20, 29, 36 and 40 were found to exclusively accumulate a cephalosporin compound other than cephalosporin C. The compound was isolated as crystals from the culture broth of the mutant No. 40, and identified as deacetylcephalosporin C, possessing a D-α-aminoadipyl side chain at C-7 by physical and chemical methods. Deacetylcephalosporin C production profile and examination of degradation rate of cephalosporin C in fermentation medium led us to the conclusion that deacetylcephalosporin C would be produced through de novo synthesis in these mutants.

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Cephalosporin C acetyl-hydrolase, which had not yet been found in Cephalosporium acremonium cultures, was partially purified from the culture fluid of the mutant No. 81 by ammonium sulfate fractionation, dialysis and DEAE-cellulose column chromatography. The optimum pH and temperature of the enzyme reaction were found to be about 8.0 and 50°C, respectively. The enzyme activity was hardly affected by Mg²⁺, Mn²⁺, Zn²⁺, Co²⁺, Ni²⁺, Na⁺, K⁺, EDTA, PCMB and 2, 4-dinitrophenol, but markedly inhibited by diisopropylfluoro-phosphate at 1mM. The product formed from cephalosporin C by the enzyme reaction was proved to be deacetylcephalosporin C by physical and chemical analyses and chromatographic behaviors.

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The bacteriostatic activity of kojic acid derivatives, where various substituents are introduced into the 2- and/or 7-positions was analyzed in terms of the physicochemical characteristics of the substituents using the method developed by Hansch and his co-workers. Analyses show that 1) activity is attributable to the neutral form of the molecule in the medium, 2) the site of action seems to be in a region close to the bacterial cell surface, and 3) the higher the hydrophobicity of the substituents at the 7-position and the greater the electron withdrawal from the 3-hydroxyl group, the stronger the activity.

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Potent L-valine producers were screened among 2-thiazolealanine resistant mutants derived from three typical L-glutamic acid producing bacteria: Brevibacterium lactofermentum, Corynebacterium acetoacidophilum, Arthrobacter citreus. By strain No. 487, the best producer derived from Brevibacterium, 31mg/ml of L-valine was produced after 72 hr when 10% glucose was supplied as a carbon source, thus giving the yield of 31% from glucose. Accumulation of the other amino acids was negligible. The addition of L-isoleucine and L-leucine in the culture medium did not reduce the L-valine production, indicating that the L-valine biosynthesis is insensitive to these end products in the L-valine producer.

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