A simultaneous assay method for L-glutamate and L-pyroglutamate contents in soy sauce using a 5-oxoprolinase (without ATP hydrolyzing activity)

L-Glutamine and L-glutamate, which are important flavor components in soy sauce, are converted to L-pyroglutamate during brewing. Therefore, it is necessary that the L-glutamate and L-pyroglutamate contents can be measured accurately. We developed a simultaneous assay method for L-glutamate and L-pyroglutamate by using 5-oxoprolinase (without ATP hydrolyzing activity) and glutamate oxidase. By this method, the L-pyroglutamate could be measured accurately in a range of 0.05 to 1.0 mM in the presence of 1.0 mM L-glutamate. This system is effective for process and quality controls.     

Hoarding of acorns by granivorous mice and its role in the population processes of Pasania edulis (Makino) Makino

In order to evaluate the role of granivorous mice, Apodemus speciosus Temminck and Apodemus argenteus Temminck, in the regeneration of Pasania edulis (Makino) Makino, an evergreen tree, we conducted field studies examining acorn crops, the population dynamics and hoarding behavior of mice and pre- and postdispersal acorn predation in an evergreen broad-leaved forest dominated by P.edulis in Kagoshima, southern Japan. The study was conducted from 1994 to 2000. Apodemus mice selected sound acorns and hoarded them in the soil after transporting them for distances ranging from 5.4 to 19.9m. This behavior appeared to be beneficial to the establishment of seedlings of P.edulis. However, the positive effects were negated by a high rate of recovery of the acorns hoarded by the mice. A life-table analysis of five cohorts of P.edulis indicated that postdispersal predation of acorns by Apodemus mice was a major contributor to annual variation in the number of new seedlings. A considerable number of acorns germinated only in years with a good acorn crop and a low level of resident mice. These results suggest that Apodemus mice are serious acorn predators rather than important dispersers. After germination, acorns were attacked by the acorn borer at a high rate. From these results, we can conclude that acorn production probably makes a smaller contribution to the regeneration of P.edulis than coppice shoot production at the study site.     

Isolation of Alkaline Protease Inhibitor Producing Microorganisms

For the purpose of obtaining microorganisms capable of producing alkaline protease inhibitor, screening test was carried out. One strain of microorganisms (No. S–3253) showed strong ability to produce alkaline protease inhibitor.

The morphological and physiological characteristics of strain S–3253 were studied. This strain was found to belong to Streptomyces albogriseolus.

When the strain S–3253 was cultivated at 45°C with a medium containing 4% polypepton, 2% starch, 0.1% yeast extract, 0.1% NaCl, 0.1% K₂HPO₄ and 0.05% MgSO₄-7H₂O in shake-flasks (pH 7.0), the highest activity was obtained after 40~48 hr cultivation.     

Purification of Two Avicelases from Aspergillus aculeatus No. F-50

An assay system for cellulases which are active on microcrystalline cellulose (Avicel) has been designed, that is, the cellulase activity was effectively assayed in the presence of endo-glucanase and β-glucosidase. Using this system, two electrophoretically distinct cellulases, which are called FI-Avicelase and FIII-Avicelase, have been purified from the culture filtrate of Aspergillus aculeatus No. F-50 to homogeneity by DEAE- and SP-Sephadex column chromatographies, and gel filtration with Sephacryl S-200. The molecular weights of the FI- and FIII-Avicelases were estimated to be 109,000 and 112,000, respectively, and their isoelectric points to be 4.7 and 4.0. Both cellulases are glycoproteins containing 20 to 30% sugar, but they differ from each other in amino acid composition.     

New Aspartate Aminotransferase Inhibitor (Gostatin) Produced by Streptomyces sumanensis nov. sp., NK-23

An isopropenyl ( = 3,3-dimethylallyl) 3-methoxyflavone (1) and its hydrate (5) were isolated from the roots of yellow lupin, Lupinus luteus L. cv. Topaz. Their structures were unambiguously determined to be 5,7,4′-trihydroxy-3-methoxy-6-(3,3-dimethylallyl)flavone (1) and 5,7,4′-trihydroxy-6-(3-hydroxy-3-methylbutyl)-3-methoxyflavone (5) by a combination of chemical and spectroscopic methods, and the new flavones were named topazolin and topazolin hydrate, respectively.

Antifungal tests against the growth of Cladosporium herbarum indicated that, in spite of its phenolic nature and the possession of an isopentenyl sidechain, topazolin (1) had only weak fungitoxic activity.     

S-SI,a New Alkaline Protease Inhibitor from Streptomyces albogriseolus S-3253

This study investigated the production of ethanol from unutilized branches pruned from pear trees by steam explosion pretreatment. Steam pressures of 25, 35, and 45?atm were applied for 5?min, followed by enzymatic saccharification of the extracted residues with cellulase (Cellic CTec2). High glucose recoveries, of 93.3, 99.7, and 87.1%, of the total sugar derived from the cellulose were obtained from water- and methanol-extracted residues after steam explosion at 25, 35, and 45?atm, respectively. These values corresponded to 34.9, 34.3, and 27.1?g of glucose per 100?g of dry steam-exploded branches. Simultaneous saccharification and fermentation experiments were done on water-extracted residues and water- and methanol-extracted residues by Kluyveromyces marxianus NBRC 1777. An overall highest theoretical ethanol yield of 76% of the total sugar derived from cellulose was achieved when 100?g/L of water- and methanol-washed residues from 35?atm-exploded pear branches was used as substrate.     

Isolation and Crystallization of Microbial Alkaline Protease Inhibitor,S-SI

S–SI, an microbial alkaline protease inhibitor, was produced in the culture broth of Streptomyces albogriseolus S–3253. S–SI was isolated from culture filtrate by salting out with ammonium sulfate, column chromatographies on DEAE-cellulose and Sephadex G–100. S–SI was also isolated by pH adjustment of the effluent from DEAE-cellulose column.

Crystallization of S–SI was carried out, and two distinct shaped crystals, needle shaped and rhombic crystal, were obtained. Homogeneity of these crystals were identified by polyacrylamide disc electrophoresis at various pHs.

S–SI retained its perfect inhibitory activity after treatment at 37°C for 25 hr in the pH range from 3 to 10, and 100°C for 10 min in the pH range from 4 to 6.

From the examination of molecular weight determination with Sephadex G–100, the molecular weight of S–SI was decided to be about 27,000.

S–SI was found to be highly specific towards microbial alkaline proteases.