There is high current interest in developing synthetic routes to oligosaccharides involved in glycoconjugates. Significant attention has been focused on the application of glycosidase-catalyzed transglycosylation for practical synthesis of oligosaccharides. The enzymatic synthesis has become more practical by the use of several glycosidases available in sufficient quantities. This review desbribes convenient syntheses of di- and trisaccharide units' which are related to molecular recognition, by using regioselective transgalactosylation, trans-N-acetylglucosaminylation, transfucosylation, and transmannosylation. The regioselectivity could be controlled to some extent by using the following techniques: (1) varying enzymed, (2) organic co-solvent system, (3) the configuration of the existing glycosidic linkage of the acceptor and (4) inclusion complex of acceptor glycoside with cyclodextrin. Furthermore, glycopolymers carrying a series of disaccharides containing β-D-galactosyl resideues were synthesized and used as a model in oligosaccharide-lectin interaction analyses. These water-soluble glycopolymers were shown to be useful as probes of carbohydrate recognition.

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Random amplified polymorphic DNA (RAPD) analysis was used to discriminate genotypes in five species of Microcystis cyanobacteria. Strains of each group with the identical allozyme genotype (T. Kato et al., Algol, Stud., 1991, 129-140; M. Watanabe, in "Toxic Microcystis, " ed. by M. F. Watanabe et al., CRC Press, Tokyo, 1966, pp. 13-34) gave similar RAPD patterns characterizing the respective group. On the other hand, no similarities in RAPD patterns were observed among strains of which allozyme genotypes were different. A good accordance between the RAPD analysis and allozyme divergence indicated a high reliability of both methods for discrimination of the affiliated groups of Microcystis. Several amplitied DNA fragment, which were expected to be markers for a particular taxon with identical allozyme genotype, were also observed on the RAPD patterns. Genetic homogeneities of M. novacekii, M. viridis, and M. wesenbergii were shown by RAPD analysis as well as the allozyme genotype. However, significant variations were observed in M. aeruginosa and M. ichthyoblabe in the levels of DNA and proteins (allozymes)

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The pathogenicity of Botrytis cinerea has been found to correlate positively with the β-glucosidase activity. In this report, the relationship between the induction of β-glucosidase and the components of host plant tissues was studied by the use of tissue fractions and cellulose-related compounds. The most active enzyme induced by the crude fiber fraction and Avicel was β-glucosidase, among the cell wall degrading enzymes tested. The β-glucosidase was very inducible in the strains with strong pathogenicity, and intensively degraded the fiber fraction made from apple fruit tissues. The same degradation of the cell wall fraction was demonstrated with the purified enzyme.

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^1H- and ¹³C-NMR spectroscopic analyses of cell wall microfibril β-1, 3-xylan from Caulerpa brachypus were performed in detail. The total assignment of all ¹H- and ¹³C-NMR signals in the β-1, 3-xylan was achieved by evaluating the 2D C-H COSY, DQF-COSY, and NOESY spectra. The results, including information on through-space interaction between the xylopyranose residues, were confirmed. The determination of the glycosidic linkages by NMR spectroscopic analyses agrees well with the results from a chemical analysis.

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GTP cyclohydrolase I (EC 3.5.4.16) has been purified for the first time from a higher plant, spinach leaves. The purified preparation appeared to be homogeneous on polyacrylamide gel electrophoresis. The molecular weight of this enzyme was estimated at 135, 000 by gel filtration and the subunit molecular weight was estimated at 35, 000 by SDS-PAGE. The latter method also suggested that this enzyme was composed of four identical subunits. The enzyme was stable to heat treatment at 50°C for 10 min, and the activity was maintained for at least six months when stored at -30°C. The enzyme had an optimum pH of around 8.0 in Tris buffer. The Hill coefficient of the enzyme was calculated to be 2.2. The pI of the enzyme was measured as 5.1 by chromatofocusing.

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To study the calcium sensitivity of sheep hair follicle transglutaminase, which was reportedly calcium-independent [H. W. Harding and G. E. Rogers, Biochemistry, 11, 2858-2863 (1972)], the enzyme was purified from a homogenate of merino sheep hair follicles and its calcium dependence was examined. As a result of purification, two types of transglutaminases (DEAE-unabsorbed and absorbed transglutaminase, DU-TG and DA-TG, respectively) were obtained. The molecular mass of DU-TG was 77 and 82 kDa by SDS-PAGE and gel filtration, respectively, while that of DA-TG was 40 and 80 kDa. Each enzyme was obviously calcium dependent and contained (a) cysteine residue(s) in the active site, like other known mammalian transglutaminases. Maximum activation of DU-TG and DA-TG was observed at 1 and 0.1 mM CaCl₂, respectively.

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The catalytic amino acid residue of Aspergillus niger α-glucosidase (ANGase) was identified by modification with conduritol B epoxide (CBE), a mechanism-based irreversible inactivator. The inactivation by CBE followed pseudo-first order kinetics. The interaction of CBE and ANGase conformed to a model with a reversible enzyme-inhibitor complex formed before covalent inactivation. A competitive inhibitor, Tris, decreased the inactivation rate. The incorporation of one mole of CBE per mole of ANGase was completely abolished the enzyme activity. A dissociated carboxyl group (-COO-) in the active site was suggested to attack the C-1 of CBE. ANGase was composed of two subunits (P1 and P2), of which P2 was modified by CBE. The labelled residue was included in a peptide (LY3) that was obtained from Lys-C protease digestion of CBE-bound P2. The sequence analysis of CBE-labelled LY3 showed that an Asp was the modified residue, that is, one of the catalytic amino acid residues of ANGase. The primary structure of LY3 was determined by analyiing the sequence of peptide fragments prepared by several proteases.

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We have investigated the effects of persimmon (Diospyros kaki) extract (PS) and related polyphenol compounds such as catechin (C), epicatechin (EC), epicatechingallate (ECG), epigallocatechin (EGC), and epigallocatechingallate (EGCG) on the growth of human lymphoid leukemia Molt 4B cells. We found that PS, ECG, EGC, and EGCG strongly inhibited the growth of the cells in a dose-dependent manner, while C and EC inhibited the growth of the cells only moderately. Ornithine decarboxylase (ODC), a rate-limiting enzyme of polyamine biosynthesis, was inhibited by 10-20% by these polyphenol compounds. The morphology of the Molt 4B cells indicated severe damage 3 days after treatment with PS, ECG, EGC, and EGCG. Irregular shape of the cells and DNA fragmentation were observed in PS, ECG, EGC, or EGCG-treated cells. These results suggest that PS, ECG, EGC, and EGCG induce apoptosis (programmed cell death) of Molt 4B cells.

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A protamine-degrading marine bacterium was isolated from marine soil and identified as Aeromonas salmonicida subsp. based on its taxonomical characteristics. An alanine-specific aminopeptidase, called aminopeptidase K, from an extract of the strain was purified and characterized. The aminopeptidase K was purified about 80-fold by fractionation with ammonium sulfate and column chromatography on QA-52 cellulose, Phenyl Superose and Superose 12. The purified enzyme is composed of 6 subunits of 86 kDa with a molecular mass of 520 kDa according to gel filtration and SDS-PAGE. The N-terminal sequence of the enzyme was H·Gly-Gln-Gln-Pro-Gln-Ile-Lys-Try-Tyr-His-Asp-Tyr-Asp-Ala-Pro-Asp-Tyr-Tyr-Ile-Thr-. It is inhibited by monoiodoacetate, N-ethylmaleimide, and puromycin. The Michaelis constant (K_m) and the maximal rate of hydrolysis (V_max) were, respectively, 0.28 mM and 49.4 μmol/min/mg for the L-Ala-β-naphthylamide substrate. The optimum pH and optimum temperature were 6.5 and 45°C, respectively. The purified enzyme was highly specific to L-Ala-β-naphthylamide.

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Enzyme activities of 2-oxoglutarate dehydrogenase complex and glutamate dehydrogenase of wild type Brevibacterium lectofementum, one of the typical glutamate-producing coryneform bacteria, were investigated by using cells cultured under glutamate-productive and glutamate-non-productive conditions. Significant reduction of the former enzyme activity was observed in the cells under the several glutamate-productive conditions, namely, in the cells cultured in media containing a) limited concentrations of biotin, b) sub-lethal amounts of penicillin, and c) sub-optimal amounts of a surface-active agent, as compared with those under the non-productive conditions. The activity of the latter enzyme was essentially unchanged in every condition. The relationship between glutamate production and the enzyme activities as well as permeability of glutamate through cell membrane was discussed from the results obtained.

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The Chitinase-producing bacterium Vibrio alginolyticus H-8 isolated from mud of Hamana Lake also produced two deacetylases for (GlcNAc)₂ extracellularly. Deacetylases DA1 and DA2 were purified from crude enzyme by column chromatography on Q-Sepharose FF, Phenyl Sepharose HP, Gigapite, and Superdex 200 HR. The final preparation was homogeneous in SDS-PAGE. The molecular weights were 48, 000 and 46, 000 for deacetylases DA1 and DA2, respectively. The pIs, optimum pHs, and optimum temperatures for deacetylases DA1 and DA2 were as follows; DA1, pI 3.3, optimum pH 8.5-9.0, optimum temperature 45°C, DA2, pI 3.5, optimum pH 8.0-8.5, optimum temperature 40°C. Both deacetylases were stable at pHs between 7.0 and 11.0 and at temperatures below 40°C. The activities of both enzymes were inhibited by Ag⁺ and Hg-<2+>. ¹H-NMR of the reaction product by deacetylase DA1 for (GlcNAc)₂ showed that the purified deacetylase selectively hydrolyzed the 2-acetamide group at the reducing end of (GlcNAc)₂.

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β-D-Gal-(1→4)-β-D-Glc-OC₆H₄NO₂-p and its isomers (β-D-Gal-(1→3)-β-D-Glc-OC₆H₄NO₂-p and β-D-Gal-(1→6)-β-D-Glc-OC₆H₄NO₂-p) were synthesized from lactose and β-D-Glc-OC₆H₄NO₂-p, using transglycosylation by the β-D-galactosidase from Bacillus circulans. This reaction was efficient enough for us to do a one-pot preparation of galactosyl-glucoside from lactose. The order of the production of the transfer products was (1→4) » (1→3) > (1→6) in the initial stage of the reaction, and the same relationship was observed for the hydrolytic rate toward the three galactosyl-glucosides. The production of (1→4)- and (1→3)-linkages greatly decreased during the subsequent reaction and much more of the (1→6)- than of the (1→4)- and (1→3)-transfer products was found in the later stage of the reaction.

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Some derivatives of 9-aminoacridine (1) were synthesized, and their frameshift mutagenicity and DNA binding affinity were studied. The introduction of a methyl group into the acridine ring of 1 reduced the mutagenic activity and the intercalative DNA binding affinity, while the introduction of chlorine increased them. Halogenated derivatived of 1 showed higher toxicity against Salmonella typhimurium TA1537.

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Thermally induced changes in pyruvate dehydrogenase complex (PDC) from B. stearothermophilus were examined mainly at temperatures from 60°to 70°C. Accompanied by inactivation of pyruvate decarboxylase, light scattering decreased, and ANS fluorescence increased. These changes including the inactivation were approximately first-order reactions, and the values of rate constants were greatly dependent on termperature. Chromatographic studies showed that any polypeptides were in associated forms and that final products were aggregates (> 230S) and an assembly (48S) smaller than PDC. The aggregates and assembly were rich in decarboxylase and lipoate acetyltransferase, respectively. It was suggested that, during the thermal denaturation, a decarboxylase was dissociated from PDC and immediately involved in aggregates.

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In order to elucidate the sterilization mechanism underlying the explosive decompression system, baker's yeast was pressurized with CO₂, N₂O, N₂, or Ar gas at 40 atm and 40°C for 4 h, and then explosively discharged. The survival ratio was markedly decreased only by the treatments with CO₂ and N₂O, which are relatively soluble gases in water, suggesting that the microorganisms' death may be highly correlated with gas absorption by the cells. Lower decompression rates to atmospheric pressure, however, led to neither any lower reduction of remaining cells nor any smaller release of total cellular proteins. Furthermore, operating with a longer treatment time and smaller number of repetitions was usually more lethal than with a shorter time and more frequent repetition. From these results, most of the yeast cells appear to have been sterilized during the pressurization process. The spore cells of B. megaterium are considered to have been killed in a somewhat different manner, because of their distinct sensitivity to the applied gases.

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A phenolic amide, N-p-coumaroyltyramine (1), was isolated as an α-glucosidase inhibitor from methanol extracts of Welsh onion (Allium fistulosum). The inhibitory activity of 1 against a yeast enzyme was as high as K_i 8.4×10^-7 M. From a structure-activity relationship study of 1 and its related compounds, the occurrence of α-glucosidase inhibitory activity required a p-coumaramide structure, with an amide hydrogen and alkyl or aralkyl substituent on the amide part.

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The isomeric ratio and level of natural xanthoxin (XAN) in tomato plants (Lycopersicon esculentum) were examined by a more reliable analytical method than has been reported before. Efforts were made to avoid artificial isomerization between c-XAN and t-XAN throughout the isolation, derivatization and GC-MS procedures. Natural XAN was separated from contaminating chlorophylls before rev. HPLC purification, derivatized to abscisic acid methyl ester (MeABA) in four chemical steps, and quantified with the deuterium-labeled internal standards on clear and reproducible full GC-EI-MS. It was revealed that the isomeric composition of natural XAN was exclusively shifted to c-XAN. The level of c-XAN was higher and more significantly induced by water stress in older plants. The significant role of c-XAN as an ABA biosynthetic precursor is suggested.

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Cyclomaltodextrin glucanotransferase from Bacillus stearothermophilus produced a series of glycosyl-trehaloses through the transglycosylation reaction with cyclomaltohexaose as the glycosyl donor and trehalose as its acceptor. After β-amylase treatment, five species of glycosyl-trehaloses were isolated by column chromatography. After chemical and enzymatic analyses, it was concluded that these oligosaccharides were α-maltosyl α-D-glucopyranoside, α-maltotriosyl α-D-glucopyranoside, α-maltosyl α-maltoside, α-maltotriosyl α-maltoside, and α-maltotriosyl α-maltotrioside. These were not hydrolyzed by salivary amylase, artificial gastric juice, or pancreatic amylase, however they were hydrolyzed by enzymes of the small intestine.

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The transport-enhancing effects of medium-chain fatty acids (caproic, caprylic, and capric acids) and their acylglycerols (mono-, di-, and triacylglycerols) were investigated by using Caco-2 cell monolayers as a model of the human intestinal epithelium. Penicillin V was used as a model for a hydrophilic bioactive compound. Among the fatty acids and acylglycerols tested, 1, 2-dicaproin, monocaprin, monocaprylin, and capric acid sodium salt effectively enhanced the transport rate, whereas other substances enhanced the rate only slightly or not at all. With each of these four substances, the rate of enhancement was proportional to the concentration at low concentrations, but leveled off at high concentrations. The transport-enhancing effects were well correlated with the reduction in surface tension and with a physico-chemical parameter, denoted by the surface energy-lowering coefficient, characterizing the surface activity of a substance.

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α_s1-Casein-specific CD8⁺ T cell clones expressed the interleukin (IL)-4 receptor, although they did not secrete detectable IL-4. We found that IL-4 significantly enhanced the secretion of interferon (IFN)-γ by these CD8⁺ T cell clones. IL-4 also enhanced the secretion of IFN-γ induced by stimulating the immobilized anti-CD3 antibodies of polyclonal CD8⁺ T cells which had been isolated from lymph nodes and were stimulated in vitro with the immobilized anti-CD3 antibody and IL-2. In addition, IL-4 added at the time of this first in vitro stimulation induced strong IFN-γ productivity, as well as IL-4 and IL-10 productivity, which were detectable upon restimulation of these cells. Results are discussed in relation to the inhibitory effects of IFN-γ production on IL-4-producing cells.

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Low sodium chloride-containing soy sauce samples were prepared by adding salty peptide and its related compounds to pre-soy sauce. The soy sauce obtained by adding Orn-Tau·HCl was very similar to commercial soy sauce in that it exhibited unadulterated saltiness and a good relative balance between salty and umami tastes. The soy sauce obtained by adding Gly-OEt·HCl exhibited a slightly stronger salty taste, while the one obtained by adding Lys·HCl had a slightly weaker salty taste at high concentrations than commercial soy sauce. The soy sauce obtained with added KCl produced a stronger umami taste at all concentrations than the commercial type. The influence of ingredients other than NaCl and MSG in soy sauce (amino acids, acids, sugars, and alcohol) on the salty and umami tastes of soy sauce was also studied. In comparison with the NaCl substituents studied here, these compounds were not as effective for influencing the apparent intensity of the taste of soy sauce when they were individually added.

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Glutamate decarboxylase (GAD) [EC 4.1.1.15] was purified from a cell-free extract of Lactobacillus brevis IFO 12005 by chromatographies on Sephadex G-100, DEAE-Sepharose CL-6B, and Mono Q. About 9 mg of purified GAD was obtained from 90.2 g of wet cells. The purified preparation showed a single protein band on SDS-PAGE. The molecular weights of purified GAD by SDS-PAGE and gel filtration on Superdex 200 were 60, 000 and 120, 000, respectively, indicating that GAD from L. brevis exists as a dimer. The N-terminal amino acid sequence of the purified GAD was NH₂-Met-Asn-Lys-Asn-Asp-Gln-Glu-Gln-Thr-. The optimum pH and temperature of GAD were at pH 4.2 and at 30°C. The GAD activity was increased by the addition of sulfate ions in a dose-dependent manner. The order of effect was as follows: ammonium sulfate > sodium sulfate > magnesium sulfate, indicating that the increase of hydrophobic interaction between subunits causes the increase of GAD activity. The purified GAD reacted only with L-glutamic acid as asubstrate and the K_m, k_cat, and k_cat/K_m values were 9.3 mM, 6.5s^-1, and 7×10² M^-1s^-1, respectively.

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We have devised a direct screening method to isolate mutations in the KAR2 gene, and have isolated a BiP/KAR2 mutant, kar2-404, from Saccharomyces cerevisiae as a small halo-forming mutant of secreted mouse α-amylase. The mutation site was identified as a point mutation at t1337 to c1337 resulting in the Ile404Thr mutation of mature Kar2-404p, located at the most NH₂-terminal first β-sheet structure (β1) of the putative peptide-binding domain. This isoleucine is highly conserved in the Hsp70 family. By pulse-chase experiments, no obvious difference was detected in the intracellular secretion rate of MFα1-prepro-signal-mouse-α-amylase between the wild type and the kar2-404 mutant. However, only about half the amount of secreted heterologous protein, mouse α-amylase, was detected in the mutant culture medium compared with wild type. A smaller amount of homologous protein, α-factor, was also detected and decreased faster in the mutant culture medium than in wild type. Kar2-404p was expressed about 3-fold more than wild type Kar2p, probably to cover its defective functions, and the turnover rates of Kar2p and Kar2-404p were about the same in vivo. The purified Kar2-404p was slightly more sensitive to chymotryptic digestion than Kar2p in vitro.

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Capillary electrophoretic methods were developed for analyzing yellow and red safflower pigments in food. Yellow safflower pigment was successfully separated by capillary zone electrophoresis (CZE) with a 300 mM borate buffer (pH 9.0), but this method could not successfully separate the red safflower pigment. The red safflower pigment was discolored in an alkaline solution. Both the yellow and fed pigments could be successfully separated by micellar electrokinetic chromatography (MEKC) with 2.0% butyl acrylate/butyl methacrylate/methacrylic acid copolymer sodium salts (BBMA), but neither pigment could be separated with 20 mM sodium dodecyl sulfate. The yellow safflower pigment was extracted from food samples (juice and candies) by solid-phase extraction cartridges and analyzed by the developed technique.

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A part of cell walls in soybean aleurone layers remained undigested after pectinase and cellulase treatments, and the features of the undigested cell walls were similar to those of Casparian strips. Glycine-rich polypeptides (GRPP) were extracted with 0.4 N NaOH from the undigested cell walls, Casparian strip-like tissues. Approximately 6.5-kDa GRPP obtained by gel-permeation chromatography from the extract was purified by anion-exchange HPLC and reverse-phase HPLC. The major amino acids of GRPP were glycine (69%) and serine (13%). The N-terminal amino acid sequence of GRPP was the some polyglycine as 30 kDa glycine-rich protein (GRP). GRPP would participate in adhesion between neighboring cells in aleurone layers because of fight binding to the cell wall.

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We constructed the plasmid pSUPmer2 by inserting tandem copies of the mercury resistance (mer) operon into a broad host range-vector, and introduced it into Escherichia coli HB101 and Pseudomonas putida PpY101 to increase their mercury resistance. Strains harboring plasmid pSUPmer2 had higher mercury resistance and mercuric reductase activity than those strains harboring the plasmid pSUPmer which had one copy of the mer operon. Mercury resistance of P.putida PpY101 was signiticantly increased by tandem insertion of the mer operon.

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Seven Cu-contaminated soils were measured for the number of bacteria grown on agar plates containing various concentrations of Cu, total Cu contents, and DTPA-extractable Cu contents. The relationship between the bacterial number grown on agar plates and concentration of Cu in the agar plates (0-1.5 mM) was well fitted to Duxbury's exponential equation. Total bacterial numbers in the soils positively correlated with the B values in the equation. The B value seemed to be a better index of biotoxic Cu amount in soil than DTPA-extractable Cu of soil. We offer a modification of Duxbury's exponential equation, in which the B value can be estimated once total soil bacterial number was counted.

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Pigskin gelatin was prepared and its molecular weight profile was examined by SDS-PAGE. The major molecular weights of gelatin were 214 kDa, 135 kDa, and 122 kDa. The secondary structure of a gelatin solution in the presence of chaotropic salt was studied by using circular dichroism (CD). The CD study clearly showed that the chaotropic salt increased the ordered secondary structure of the gelatin solution due to the altered water structure.

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α-Chymotrypsin-catalyzed transesterification of N-acetyl-L-tyrosine methyl ester in ethanol was markedly accelerated by addition of small amounts of divalent metal salts. The reaction rate depended not only on the nature of metal ions but also on the nature of anionic counter ions. Calcium acetate was the most effective among the metal salts used. The reaction followed Michaelis-Menten kinetics, and it was found that the reaction increase is due to the increase in k_cat.

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Novel fluorescence-labeled abscisic acid was synthesized by introducing a fluorescent functional group into the 4' position of abscisic acid via 4-aminophenylcarbohydrazide as a spacer. The inhibitory activity toward amylase induction by this chemical was evaluated by using aleurone protoplasts, and it was demonstrated that the analogue possessed abscisic acid-like activity.

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It is known that deaths attributable to pellagra, which is considered to be a disease caused by the disturbance of tryptophan metabolism, have been approximately two-fold higher in women than in men. We investigated the effects of the administration of female and male sex hormones on the contents of tryptophan and such metabolites as serotonin, nicotinamide, N¹-methylnicotinamide, N¹-methyl-2-pyridone-5-carboxamide, and N¹-methyl-4-pyridone-3-carboxamide, and on the conversion ratio of tryptophan to niacin in male rats. Feeding a diet containing estrone or testosterone had no effect on the concentrations of tryptophan and serotonin in the blood and brain, or on the concentration of 5-hydroxyindole-3-acetic acid in the brain. On the contrary, feeding a diet containing estrone caused to a decrease in the urinary excretion of nicotinamide, N¹-methylnicotinamide, N¹-methyl-2-pyridone-5-carboxamide, and N¹-methyl-4-pyridone-3-carboxamide, and of the conversion ratio of tryptophan to niacin when compared with the control rats. Feeding a diet containing testosterone had no effect on any parameter. We postulate from these findings that the cause of higher pellagra deaths in women than in men is attributable to the decrease in the formation of niacin from tryptophan, but not in the formation of serotonin by the female hormone. It seems likely that female sex hormones inhibit the synthesis of niacin from tryptophan, and that women, especially during pregnancy, will be more at risk to pellagra than are men.

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Structural features of the sulfated polysaccharide-peptidoglycan complex from an Arthrobacter species were examined. The molecular weight was estimated to be from 13, 000 to 15, 000. The complex mainly consists of galactose and glucose at a molar ratio of 5:1. Glutamic acid, glycine, alanine, and diaminopimelic acid (DAP) were found to be present at a molar ratio of 1:1:2:1.

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The effect of chitosan on calcium (⁴⁷Ca) metabolism was investigated in rats. The whole-body retention of ⁴⁷Ca by rats fed on a 5% chitosan diet was significantly decreased when compared with that of rats fed on a cellulose diet, but showed no significant difference from that of rats fed on a tiber-free diet. Although there was no significant differente in the fecal excretion of ⁴⁷Ca between the chitosan group and the cellulose or fiber-free group, the urinary excretion of ⁴⁷Ca was significantly increased in the chitosan group when compared with the cellulose group. These results suggest that dietary chitosan would affect thle calcium metabolism in animals.

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The solubility of iron ions with phosphoryl oligosaccharides (POs) from a potato starch hydrolysate was investigated in the presence of bicarbonate and phosphate salts. The oligosaccharides were separated into two fractions, PO-1 and PO-2. PO-1, having one phosphoryl residue, solubilized equivalent moles of iron, and PO-2, having two phosphoryl residues, solubilized more than 10-fold equivalent moles of iron. The number of phosphate groups attached to the molecule influenced the solubility of iron. The ability of PO-2 was equal to that of casein phosphopeptide (CPP) which is currently used as an iron solubilizer for food.

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A shuttle vector, pBLES100, was constructed by cloning a Bifidobacterium longum plasmid and a gene encoding spectinomycin adenyltransferase AAD(9) from Enterococcus faecalis into the Escherichia coli vector pBR322. Stable transformants with this plasmid were obtained with an efficiency of 2.2×10⁴ transformants/μg DNA or 6.9×10^-5 transformants/cell/μg DNA under the optimal conditions of 10.0 kV/cm, 200Ω, and 25μF, using B. longum 105-A harvested at late log phase of growth.

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The 4-acetoxyquinolines possessing 2-alkyl, alkenyl, and 6-fluoro groups were synthesized and their insecticidal activities were evaluated.

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An aminoacylase, inducibly formed in Bacillus thermoglucosidius grown with a synthetic compound, acetamidocinnamate, was used for enzymatic synthesis of L-phenylalanine from chloroacetamidocinnamate. The reaction system consisted of the hydrolysis of chloroacetamidocinnamate to phenylpyruvate by aminoacylase and the reductive amination of phenylpyruvate to L-phenylalanine by phenylalanine dehydrogenase. The coenzyme NADH consumed was regenerated by a coupled reaction with formate dehydrogenase. Under optimum conditions for L-phenylalanine production, more than 98% of the initially added chloroacetamidocinnamate was converted effectively to L-phenylalanine without appreciable decomposition or racemization.

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Coelenterazine is poorly soluble in water except at alkaline pH values that promote auto-oxidation. The solubility is markedly increased by adding hydroxypropyl-β-cyclodextrin in a neutral buffer solution, the solubilization being most effective in the pH range of 6.5 to 7.0. The concentration of coelenterazine dissolved in a pH 7.0 buffer containing 50mM hydroxypropyl-β-cyclodextrin was about 280-fold higher than that without the additive.

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We found that CPY production in Saccharomyces cerevisiae KS58-2D/pCY303 was increased by the addition of thiamine into the medium, while the addition of thiamine had no effect on cell growth. It became clear that the positive effect of thiamine was due to transcriptional increase, because the levels of CP YmRNA were increased according to the amount of thiamine added. Furthermore, it was suggested that thiamine generally increases the expression of yeast genes, since the expression of the luciferase gene that was artificially constructed was also increased to some extent by thiamine in S. cerevisiae.

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Magnaporthe grisea, the causal agent of rice blast disease, differentiates an appressorium to penetrate through the host cuticle with an infection peg elaborated from the appressorium. Similar reaction is observed on various synthetic substrata. By using a hardness-adjustable material, Hycel A-342, the correlation between appressorium formation and substratum hardness was evaluated. The results suggested that substratum hardness played an important role in triggering appressorium formation of M grisea. Furthermore, growth orientation of germ tubes was coerced by the hydrophobicity of the contact surfaces. When conidia germinated at the interface of two differently hydrophobic phases, the germ tubes grew preferentially towards the more hydrophobic phase. Mutagenesis studies suggested that loss of this anti-hydrotactic behavior impaired appressorium formation. Since water is a pre-requisite for germination, we propose that the anti-hydrotactic response initiates attempted penetration into the plants by germ tubes, then triggers appressorium formation by the surface hardness.

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A well-defined X-ray fiber pattern of chitosan acetate was obtained by immersing a tendon chitosan, prepared from a crab tendon chitin by a solid-state N-deacetylation, in an aqueous acetic acid-isopropanol solution at 110°C. This pattern was very similar to that of chitosan salts with some inorganic acids, such as HF, HCl, and H₂SO₄, in which chitosan chains form an 8/5 helix, indicating that chitosan acetate also take up this conformation. This information may give an influential clue to the chitosan conformation in the aqueous acetic acid solution, the most popular solvent for chitosan. However, after one month of storage of the chitosan acetate, the fiber pattern, the density and its IR spectrum changed to those of the anhydrous polymorph of chitosan, suggesting that the acetic acid was removed accompanied with water molecules from the crystal during storage and that the polymorph can be obtained not only by annealing chitosan, but also through the chitosan acetate.

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