Detection of Polygalacturonase in Kiwifruit during Ripening

Oligosaccharides produced during the course of the hydrolysis of 25% N-acetylated chitosan by Streptomyces griseus chitinase were fractionated by CM-Sephadex C-25 and Toyopearl HW-40F column chromatographies. Sugar compositions and sequences of main oligosaccharides were identified by N-acetylation, exo-splitting with β-GlcNAcase and β-GlcNase, and nitrous acid degradation. In addition to N-acetylated saccharides, GlcNAc, (GlcNAc)₂, and (GlcNAc)₃, hetero-chitooligosaccharides such as GlcN · GlcNAc, GlcN · GlcNAc · GlcNAc, GlcN · GlcN · GlcNAc, GlcN · GlcNAc · GlcNAc · GlcNAc, GlcNAc · GlcN · GlcNAc · GlcNAc, GlcN · GlcNAc · GlcN · GlcNAc, and GlcN · GlcN · GlcNAc · GlcNAc were identified. These results indicate that Streptomyces griseus chitinase specifically cleaves the N-acetyl-β-d-glucosaminidic linkages in partially N-acetylated chitosan.     

Effect of Drying Methods on Quality of Leaf Protein Concentrate

Glutathione thiol esterase activity in cell extracts of a yeast: Saccharomyces cerevisiae was separated into three peaks when filtered on a Sephadex G-150 gel column. One of the enzymes in these peaks was purified. The enzyme was a single polypeptide chain with a molecular weight of 28,000 and catalyzed the complete hydrolysis of S-acetylglutathione and S-lactoylglutathione. S- Methyl-, S-hexyl-, S-glyceryl-, S-succinylglutathiones, and acetyl CoA were not hydrolyzed. In addition to the hydrolytic activity, the purified enzyme showed a group transfer activity and catalyzed the formation of acetyl CoA from S-acetylglutathione and CoA. The purified enzyme was not identical with glyoxalase II in molecular weight, substrate specificity, or behaviors toward inhibitors.     

Effects of 1-Aminocyclopropane-1-carboxylic Acid Production on the Changes in the Polyamine Levels in Hiproly Barley Callus after Auxin Withdrawal

Contents of polyamines and 1-aminocyclopropane-1-carboxylic acid (ACC) in Hiproly barley callus were examined under different culture conditions. After auxin withdrawal, the contents of free polyamines changed conversely to the contents of ACC. In the absence of auxin, incorporation of l-[3,4–¹⁴C]methionine into polyamines and the activity of S-adenosylmethionine decarboxylase (SAMDCase) in the callus increased, then remained stable, but incorporation of l-[3,4- ¹⁴C]methionine into ACC, precursor of ethylene and ACC synthase activity once declined and increased again.

Aminooxyacetic acid (AOA) affected the increase in the levels of polyamines in the callus. 1- Aminoisobutyric acid (AIB) had a slight effect on the polyamine production. The incorporation of l-[3,4–¹⁴C]methionine into ACC and ACC synthase activity were inhibited by AOA, but not by « 4 AIB. AOA stimulated the activity of SAMDCase, and also enhanced the incorporation of l-[3,4- ¹⁴C]methionine into polyamines in the callus. Methylglyoxal-bis(guanylhydrazone) (MGBG) greatly enhanced the ACC production. The rate of incorporation of l-[3,4–¹⁴C]methionine into ACC and ACC synthase activity in the callus were significantly enhanced by MGBG. MGBG strongly inhibited SAMDCase activity and the incorporation of l-[3,4–¹⁴C]methionine into polyamines. Moreover, the synthesis of polyamines was inhibited by MGBG.

These results suggested that in Hiproly barley callus ACC production has an important effect on changes in the polyamine levels, and that polyamine and ethylene biosynthetic pathways are regulated by competition against each other.     

Production of a Gaseous Saturated-hydrocarbon Mixture by Rhizopus japonicus under Aerobic Conditions

The microbial production, by the genus Rhizopus, of a gaseous saturated-hydrocarbon mixture was studied under aerobic conditions. Rhizopus strains, comprising 13 strains of 9 species, were tested as to their ability to produce a gaseous hydrocarbon mixture. Except for one strain, all the strains tested produced more than two kinds of gaseous hydrocarbons simultaneously when grown in nutrient broth containing glucose. Rhizopus japonicus IFO 4758 was selected as being typical of these producers of mixed gaseous hydrocarbons. When this organism was cultivated in a synthetic medium supplemented with l-cysteine under aerobic conditions, the maximum production of the total gaseous hydrocarbon mixture reached ca. 10 nl/ml culture broth/hr. The gaseous hydrocarbon mixture produced was composed mainly of paraffin hydrocarbons, i.e., ca. 74% pentane, ca. 16% propane and a trace amount of methane. The ratios of saturated to unsaturated, and even to odd number hydrocarbons produced by this fungus were 95 : 5 and 90: 10, respectively. The biosynthetic pathways for the production of these gases are discussed in comparison with the biosynthetic pathways for ethylene and isobutene in microorganisms.     

Purification and Separation of Eight Steroidal Plant-growth Regulators from Dolichos lablab Seed

Purification and separation of eight steroidal plant-growth regulators, dolicholide, dolichosterone, homodolicholide, homodolichosterone, brassinolide, castasterone, 6-deoxocastasterone and 6-deoxodolichosterone, from immature seed of Dolichos lablab were accomplished using various chromatographic techniques. The reversed-phase HPLC of a number of steroidal plant growth regulators was also studied.     

Aggregation and Fragmentation of Phaseolus vulgaris Lectin

The effects of temperature on 6-O-α-maltosyl cyclodextrins (G₂-CDs) production from α- maltosylfluoride (α-G₂F) and cyclodextrins (CDs) by the transfer action of debranching enzymes such as pullulanase and isoamylase were studied.

The amounts of 6-O-α-maltosyl α-cyclodextrin (G₂-α-CD) production by purified pullulanase from Aerobacter aerogenes (A-pullulanase) and from Bacillus acidopullulyticus (B-pullulanase) increased with a rise in temperature, e.g., the amounts at 60°C were about 1.5 times higher than those at 30°C. Initial transfer ratios (G₂-α-CD formed/α-G₂F consumed) of A-pullulanase and B- pullulanase were about 62% and 25% (at 40°C), and about 50% and 15% (at 20°C), respectively. The transfer ratios of both A-pullulanase and B-pullulanase in the reaction using β-CD or γ-CD as acceptor also increased with a rise in temperature.

The transfer ratios were little affected by any change in temperature or any kind of acceptor CDs, in the case of isoamylase, and were about 60%.     

Studies on the Browning Compounds of Broad Bean,Vicia fava L.

Browning of green broad bean appears only in the seed-coat, and not in cotyledon. This phenomenon coincides with the facts that phenolic compounds such as l-tyrosine and 3,4-dihydroxyphenylalanine are localized in the seed-coat tissues. But little is known about the browning mechanism of the seed-coat at present.

In this study, the presence of dopa-o-β-d-glucoside was confirmed in addition to those phenolic compounds mentioned above, and the distribution of this substance in tissues of green broad bean was examined by paper chromatography. A clear indication of the relationships between the mechanism of brown pigmentation and the biosynthesis of dopa-o-β-d-glucoside in vivo was also presented.     

An abundant LEA protein in the anhydrobiotic midge,PvLEA4, acts as a molecular shield by limiting growth of aggregating protein particles

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Differences in sex expression and mating systems in three pollination morphs of Cimicifuga simplex

Cimicifuga simplex (Ranunculaceae) has three genetically distinct pollination morphs. Here, we report that each of the three pollination morphs of C. simplex differs from the others with regard to sex expression and mating system: morph I consists mostly of ramets with hermaphroditic flowers and ramets with only female flowers, morph II consists of ramets with hermaphroditic flowers and ramets with hermaphroditic and male flowers, and morph III consists mostly of ramets with hermaphroditic flowers. A microsatellite analysis of seed DNA showed that morph III has a high self-fertilization rate. Flowering season and flower visitor assemblages, which also differ among the three morphs, may influence the evolution and maintenance of the differences in sex expression and mating systems in the morphs.