This work aimed at establishing a process for removal of phenylalanine from the enzymatic hydrolysate of a milk whey protein preparation to obtain a low-phenylalanine peptide mixture. Rhodotorula rubra IAM 4989 was screened as the most suitable strain for metabolizing phenylalanine with no appreciable product inhibition. The intact cells indiscriminately consumed all the constituents of the enzymatic hydrolysate, but cells entrapped in a polypyrrole matrix consumed only low-molecular-weight components to give a low-phenylalanine peptide mixture in a high yield. This selectivity was due to the different permeabilities of the constituents of the hydrolysate through the polypyrrole membrane. The entrapped cells retained their phenylalanine-decomposing activity for at least 4 weeks.

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Weiner's model, originally presented for a multi-phase-transition problem for alloys, was applied to analyze the freezing of food gels in which the fraction of frozen water gradually changes with temperature. This model includes Neumann's model as its special case. The effect of the temperature-dependency of the fraction of frozen-water, measured by differential scanning calorimetry, was well incorporated into the theoretical model consideration. Theoretical predictions compared well with the experimental results. The advantages of this model are discussed compared with other theoretical models for freezing and thawing of food materials.

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Pore size distribution was measured for two kinds of rice grains differing in the tendency of digestibility to investigate the relationship between the fine structure and digestibility.
The solute exclusion method was used to measure the pore size distribution. The center of the distribution in steeped rice was about 10Â in diameter and there was little difference between the two kinds of rice. The pore size distribution in swollen steamed rice varied by the conditions of processing, and the tendency was different between the two kinds of rice. The digestibility also varied with the conditions of processing.
The relationship between the fine structure and digestibility was considered from these results.

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Two proteinases (I and II) from a marine luminous bacterium, FLN-108, were purified to homogeneity. The molecular weights of proteinases I and II were estimated to be 49, 000 and 46, 000, comprising a dimer of 23, 000 molecular weight subunits, respectively. These enzymes were most active at from pH 8.0 to pH 9.0 and 50°C, and stable below 45°C. These enzyme activities were inhibited by EDTA and orthophenanthrolin. Phosphoramidon inhibited the activity of proteinase II, but not that of proteinase I. Metal ions such as Cu²⁺, Hg²⁺, and Ni²⁺ strongly inhibited these activities. These results indicate that the proteinases I and II are metal-chelater-sensitive, alkaline proteinases.

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To obtain a lipase which effectively hydrolyzes castor oil, bacteria were isolated from 500 soil samples. The best strain was examined; its microbiological characteristics suggested that it belongs to the genus Pseudomonas. A lipase from this strain was purified by ammonium sulfate fractionation and chromatographies on DEAE-cellulose and DEAE-Toyopearl 650 M. The enzyme was purified about 400-fold with a yield of 13%. The purified enzyme was electrophoretically homogeneous and its molecular weight was 30, 000. The optimum pH and temperature for the hydrolysis of olive oil emulsion were 7.0 and 60°C. The enzyme was stable up to 35°C at pH 7.0 for 30min and also stable from pH 9.0 to 10.0 at 4°C for 22 hr. The activity was inhibited by Fe³⁺, Hg²⁺, pCMB, and anionic surfactants, and enhanced by nonionic surfactants and bile salts. The enzyme efficiently hydrolyzed castor oil.

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Microorganisms that enantioselectively hydrolyze 1-cyanoalkyl acetates (aldehyde cyanohydrin) were screened. Candida tropicalis was found to be the best. The enzyme system of this strain catalyzed the enantioselective hydrolysis of (S)-isomers, leaving behind the (R)-acetates. The optical purities of recovered acetates were high as measured by ¹H-NMR analysis in the presence of a chiral shift reagent.

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A glycopeptide was isolated from a peptic hydrolysate of chicken ovomucoid using gel filtration after reduction with 2-mercaptoethanol. The glycopeptide was thought to be derived from the sequence Gly⁵¹-Tyr⁷³ of chicken ovomucoid and retained the immunoreactivity to IgG of mouse antiserum and IgE of human serum specific to ovomucoid. About fifty percent of the immunoreactivity to mouse antiserum was inhibited by the sera of patients allergic to ovomucoid and also by the carbohydrate chains on ovomucoid. These results suggested that the glycopeptide, connecting the first domain and second domain of chicken ovomucoid, participated in egg allergy, and the ovomucoid carbohydrate chains contributed to the immunoreactivity of the glycopeptide.

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From 1.2 × 10⁶male adult heads of the silkworm, Bombyx mori, 0.16mg of bombyxin-IV was isolated, which was a novel molecular species of bombyxin, previously called 4K-prothoracicotropic hormone. Injection of 0.1 ng of bombyxin-IV into a dauer pupa of the Eri-silkworm, Samia cynthia ricini, evoked adult development. Microsequencing, chemical modification, enzymatic digestion, and fast atom bombardment mass spectrometry showed that bombyxin-IV consisted of two heterogeneous peptides linked by disulfide bonds and had a considerable sequence homology (62.5%) with bombyxin-II.

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Two strains of Bacillus species capable of producing α-D-xylosidase were isolated from soil samples by a novel method using glucose oxidase. They were facultatively anaerobic, gramnegative, and mesophilic, and formed ellipsoidal, central/terminal endospores. The guanine+ cytosine content of the DNA were 50.8mol% for strain No. 208-918-1 and 44.5mol% for strain No. 693-1. The profiles of physiological and biochemical features of both strains were almost identical and differed from those of the previously described species of Bacillus. It was found that α-D-xylosidase of strain No. 693-1 was a typical inducible enzyme induced by methyl α-D-xyloside and isopropyl α-D-xyloside. The optimum conditions for the production of α-D-xylosidase were found to be a 1:1 ratio of glucose/peptone and an inducer concentration (methyl α-D-xyloside) of 1.0% in the medium. Moreover, the addition of CaCl₂ into the medium enhanced α-D-xylosidase production.

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Bile pigments in the bile of the rainbow trout, Salmo gairdneri, tilapia, Tilapia nilotica, and pejerrey, Odonthetes bonariensis, were analyzed by HPLC and TLC.
Major bile pigments of rainbow trout and pejerrey were bilirubin glucuronides and ditaurobilirubin, respectively. Ditaurobilirubin was not detected in rainbow trout and bilirubin glucuronides were scarcely found in pejerrey. Biliverdin seemed to be the sole bile pigment in tilapia, but it was a minor component in the other fish. These results are in accord with the previous reports in which the diversity of bile pigment composition was demonstrated in some fish.

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Two lytic enzymes (enzyme I and enzyme II) that lysed Micrococcus lysodeikticus were isolated from the crude extract of Polysphondylium pallidum myxamoebae grown in the presence of Klebsiella aerogenes by precipitation with protamine sulfate and by chromatography on DEAE-Sepharose CL-6B. Enzyme I was further purified by gel filtration on a Superose12 column, and enzyme II by chromatography on a MonoQ HR 5/5 column and gel filtration on a Superose12 column. Enzyme I was a basic protein, while enzyme II was acidic. The molecular weights of enzyme I and II were about 14, 000 and 22, 000, respectively by SDS-polyacrylamide gel electrophoresis. Optimum pHs for the activity were 5.0 for enzyme I and between 3.5 and 4.0 for enzyme II. The maximum activity of enzyme I and II was obtained at 65°C and 45°C to 55°C and at ionic strength of 0.0075 to 0.03 and 0.06, respectively. Both enzymes cleaved the glycosidic bond of β(1, 4)-N-acetylmuramyl-acetylglucosamine of the cell wall peptidoglycan of Micrococcus lysodeikticus. These results indicate that the two lytic enzymes of Polysphondylium pallidum myxamoebae are N-acetylmuramidases.

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A gene complementing a ura3 mutation in Saccharomyces cerevisiae was isolated from Kluyveromyces lactis. Its nucleotide sequence showed an open reading frame of 801 bp, corresponding to 267 amino acid residues. These are homologous to the coding region of URA3 gene of S. cerevisiae, 71% and 82% at the nucleotide and the amino acid levels, respectively. Although transcription started at -30 to -40 from the initiation codon ATG, which is comparable to S. cerevisiae, the regulatory sequences identified in the 5' flanking regions of URA1 and URA3 genes of S. cerevisiae are not found in the URA3 gene of K. lactis.

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Two NAD-dependent dehydrogenases which oxidize secondary alcoholic groups at the C_α-position of dimeric lignin model compounds were purified from Pseudomonas sp. TMY1009. These enzymes have been designated C_α-dehydrogenase I and II (DH-I and DH-II). DH-II was purified to electrophoretic homogeneity. The molecular weight of DH-II, which is composed of four identical subunits, is 125, 000. DH-I was partially purified and the molecular weight of DH-I is 94, 000. Both DH-I and DH-II are active for three kinds of dimeric lignin model compounds related to major lignin substructures, although their specificities and affinities are different.

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Polymorphism exists in L-glutamic acid crystals where the α-form is a coarse pyramidal crystal, while the β-crystal usually has shapes like needles or leaflets with a high moisture content. A method to obtain good α-crystals stably was established. More than 95% pure α-crystal, which was prepared from a solution of less than 5% monosodium glutamate, was effective as seeds in the crystallization process with the standard neutralization curve. Separation of the inhibitory material for β-transition of α-crystals was pursued using two kinds of testing methods in fractions of beet molasses broth treated with ion exchange resins. The neutral part of the beet molasses broth contained an active agent which was identified as saponin.

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Under heterogeneous conditions, a lipase (Amano P) catalyzed the asymmetric ring opening of 3-substituted glutaric anhydrides with 1-butanol in diisopropyl ether to afford the R mono esters, which were converted to the 3-substituted δ-lactones having 60-93%e.e. This process offered a practical means for preparing optically active 3-methyl-δ-valerolactone (93%e.e.) which is a useful chiral building block. The enzyme hydrolyzed the corresponding dimethyl esters to give the S mono esters in an aqueous medium. In both reactions, the pro R carbonyl group was preferentially attacked to yield pairs of enantiomers.

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Mutagenicity of the anti-cancer agent mitomycin C was suppressed by incubation with the desmutagenic factor of Pseudomonas convexa 4-87 and NAD(P)H. The main reaction products were isolated and identified as 1, 2-cis- and l, 2-trans-2, 7-diamino-1-hydroxymitosene and 2, 7-diaminomitosene. A reaction scheme through reduction of the benzoquinone moiety, elimination of the methoxy group, opening of the aziridine ring, and formation of mitosene-type derivatives was proposed. The desmutagenic factor of P. convexa 4-87 was shown to be a quinone-reducing enzyme requiring NAD(P)H, but its physiological role in the cell remains unclear.

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We investigated the distribution of glutamate racemase (EC 5.1.1.3) in bacteria, and found that the enzyme occurs exclusively in lactic acid bacteria. Pediococcus pentosaceus IFO 3182 produces the enzyme most abundantly. The enzyme purified from extracts of the Escherichia coli clone cells carrying the plasmid pICR221, which contains the enzyme gene of P. pentosaceus, does not require cofactors for its catalytic activity [N. Nakajima, K. Tanizawa, H. Tanaka and K. Soda, Agric. Biol. Chem., 50, 2823 (1986)]. This cofactor dispensability was re-confirmed with the enzyme purified from cell extracts of P. pentosaceus. On the basis of kinetic parameters obtained by measurements of the initial velocities, the glutamate racemase reaction was categorized into a typical racemization with a calculated equilibrium constant of 1.05. D- and L-Glutamate were the specific substrates for the enzyme, although L-homocysteinesulfinate, a sulfur analog of L-glutamate, slightly served as a substrate. L-α-Aminoadipate behaved as a competitive inhibitor in the racemization of glutamate. The enzyme was inactivated significantly by treatment with various thiol-blocking reagents.

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A morphological mutant of Neurospora crassa, which showed great changes in cell wall β-glucan structures, was obtained. The mutant lacked spore-forming ability. Chemical analysis indicated that the mutant cell walls had more carbohydrates and less proteins than the wild type. In the structural polymers of cell walls, heteroglycan and chitin were not apparently changed in their sugar composition and structures. On the other hand, the alkali-soluble β-glucan of this mutant showed significant changes in the chemical structure, particularly, the number and length of branches. The mutant glucan had about 2.5 times as many branches as that from wild type and the number of 1, 3-linked glucose residues was greatly reduced.

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Expansion of a paraffin oil droplet in a gelatin gel was explained by an equation given by Gent and Tompkins which takes into account the effects of internal pressure, elasticity, and surface tension. The equation suggests that large bubbles monotonously expand as the internal pressure increases but small bubbles have to surpass maxima in the internal pressure for expansion. It was shown that there was a characteristic value in the initial bubble radius, r'_c, above which the bubbles expand monotonously as the internal pressure increased, and it was given as r'_c = 3σ/E (σ: surface tension, E: elasticity). The calculated value of r'_c, agreed with the minimum of radii of bubbles reported in the preceding paper, which expanded even at a constant temperature, absorbing the air released from other shrinking small bubbles. However, for the critical radius of bubble expansion at an elevated temperature, further study is needed.

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Curvularin, 8-dehydrocurvularin, and 8-hydroxycurvularin as well as a minor new metabolite, 8-methoxycurvularin, were isolated as fungal metabolites having cytotoxic activity toward sea urchin embryogenesis. Curvularin induced barrel-shaped mitotic spindles and 8-dehydrocurvularin caused miniature spindles. They were shown to act on components of the mitotic apparatus and to effectively inhibit cell division.

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The β-isopropylmalate dehydrogenase (β-IPMDH) gene of Acetobacter aceti No. 1023, which complemented the leuB mutation of Escherichia coli, was cloned and expressed in E. coll. Plasmids pCAL1 and pCAL4, carrying a 5.44 kilobase pairs (kb) HindIII-fragment in the opposite orientation, conferred the same β-IPMDH activity as that of the wild type strain of E. coli. Restriction mapping and deletion analysis indicated that the β-IPMDH gene was located on a 1.65kb AatII-HindIII fragment. Plasmids pMVL1 and pMVL2, composing the cloned β-IPMDH gene and plasmid pMV102, a plasmid indigenous to Acetobacter, were constructed as plasmid cloning vectors which allow selection of leu⁺ transformants in an A. aceti leu^- host. The A. aceti leu^- host was obtained through the insertional inactivation occurring as a result of homologous recombination between the chromosome of A. aceti and the cloned β-IPMDH gene, which was disrupted by insertion of the kanamycin resistance gene from pACYC177 into the BamHI site in the AatII-HindIII fragment. This system constitutes a relatively simple technique for gene disruption or replacement in Acetobacter that requires a single transformation.

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2-n-Heptyl-4-hydroxyquinoline-N-oxide (KF8940), isolated from Pseudomonas methanica, was a potent and selective inhibitor of the arachidonate 5-lipoxygenase of rat basophilic leukemia (RBL-1) cells. Kinetic analysis indicated that the inhibitory mode was non competitive. The Ki value was 3.5 × 10^-7 M. KF8940 also inhibited 12-lipoxygenase of bovine platelets in a noncompetitive manner, but with a Ki value of 7 × 10^-5 M. lonophore A23187-stimulated SRS generation from rat peritoneal cells and antigen-stimulated SRS-A generation from sensitized rat lung were significantly inhibited by KF8940. KF8940 at a dose of 10 mg/kg (p.o.) suppressed the passive anaphylactic bronchoconstriction in guinea pigs.

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The effects of different dietary levels of gamma-linolenic acid (GLA) on lipid metabolism was studied in rats using a combination of evening primrose oil (EPO) and palm oil (PLO). EPO compared to PLO significantly reduced liver cholesterol and triglyceride after 4 weeks of feeding, and the effect remained even when EPO was mixed with PLO at the same weight basis. The serum triglyceride level also tended to be low on feeding EPO. Neither liver Δ6-desaturase and phospholipase A₂ activities nor aortic production of prostacyclin and thromboxane A₂ production by platelets were influenced significantly by the fat type, suggesting a peculiar effect of PLO. The percentage of arachidonic acid in liver, serum, and aortic phosphatidylcholine depended on the dietary level of GLA. A more distinct increase in arachidonic acid was observed in tissue triglycerides of rats fed EPO. GLA appears to exert favorable effects on lipid metabolism even when the P/S ratio was lowered from 13.7 of EPO to 1.8 of the 1:1 mixture of EPO and PLO.

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Mouse myeloid leukemia cells, Ml, were induced to differentiate into phagocytes by treatment with ascofuranone (AF). AF also induced differentiation of human promyelocytic leukemia HL60 cells and human erythroid leukemia K562 cells into granulocytes and erythrocytes, as detected by nitroblue tetrazolium reducing activity and benzidine staining, respectively.
The antibiotic enhanced acetate incorporation of K562 cells. The increase was not observed with the cells of HL60 and two human B lymphoma lines, Daudi and Raji. The increase was diminished by the addition of a glycolysis inhibitor, deoxyglucose. Inhibitors of respiration, antimycin and sodium azide, also enhanced acetate incorporation of K562 cells specifically, which was diminished by the addition of deoxyglucose. Furthermore, antimycin induced differentiation of K562 and HL60 cells. These results suggest a possible relationship between cell differentiation and inhibition of respiration.

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Total lipid was extracted effectively by the acidified Blight and Dyer solvent system from Methanobrevibacter arboriphilicus A2 cells. The lipid content was 5.8% of dry cell weight. Cell disruption was required for the maximum yield of lipid from the cells. Eighteen polar lipids were detected and their composition was measured. Phosphoglycolipids from several species of Methanobacteriaceae which had the similar mobilities on thin-layer chromatograms were suggested as the common lipid of the family. The phosphoglycolipid (PGL1, 30%) from M. arboriphilicus was identified as gentiobiosyl caldarchaetidylinositol, which was identical to PGL1 of Methanobacterium thermautotrophicum. This confirmed that the lipid could be designated as the signature lipid of the family. The structure of the other major polar lipids were also identified as follows: gentiobiosyl caldarchaeol (GL1a, 9.9%), gentiobiosyl archaeol (GL1b, 12.6%), caldarchaetidylinositol (PL2a, 10.6%) and archaetidylinositol (PL2b, 3.1%).

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Most of the lipoxygenase (LOX) activity in cucumber seedlings was detected in the cotyledons. Other tissues, such as the hypocotyls and roots, showed low but appreciatable activities. During seed germination, LOX activity increased once, then declined in both the cotyledons and roots. The activity was predominantly recovered in the cytosol fractions after differential centrifugation of both tissues. The soluble enzymes were partially purified from both the roots and cotyledons. Root LOX was most active at pH 8.0, but the cotyledon enzyme was at pH 6.0. We propse that LOX in the cotyledons may differ from the enzyme in the roots.

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A fungal naphthoquinone, PO-1, was rapidly absorbed by alfalfa callus, and a prominent accumulation of 4', 7-dihydroxyflavone, 1-(2, 4-dihydroxyphenyl)-3-(4-hydroxyphenyl)-1, 3-propanedione and 6-hydroxy-4', 7-dimethoxyisoflavone was seen in the PO-1-treated callus. This 1, 3-propanedione (β-hydroxychalcone) showed pronounced antifungal activity.

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