Weexamined the distribution of mercury and selenium in fifteen tissues of striped dolphins (Stenella coeruleoalba). The total mercury level in the mature dolphins showeddifferences among the tissues and was highest in the liver. The total mercury concentration in most tissues increased with age, and reached a constant level at 20 to 25 years of age. The total mercury level in the tissues was not appreciably different among mature males, pregnant females, lactating females and resting females. In the muscle of mature individuals, the total mercury level of striped dolphins collected in 1977 and 1980 was appreciably higher than that of those collected 1978 and 1979. Methylmercury showed less variation in concentration amongthe tissues. The ratio of methylmercury to total mercury in muscle decreased with growth after about 10 years of age when the increase of methylmercury stopped. Selenium levels in the dolphins increased with age as total mercury levels did. High correlation coefficients were found between the total mercury and selenium levels in spleen, muscle, pancreas and liver. The concentrations of total mercury in the various tissues of immaturedolphins were muchlower than those of mature ones.

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Weexamined variations in the burden of total mercury and selenium with age in striped dolphins (Stenella coeruleoalba). The amount of total mercury accumulated in the whole body increased with age and reached a constant level at about 16 years of age. The constant total mercury burden level in males was slightly higher than that of females. A similar tendency was observed for the body burdens of methylmercury in males and females. The body burden of selenium remained constant for the dolphins of ages between 5 to 12 years, and after that it sharply increased with growth until about 17 years of age. The sum of total mercury in muscle, liver and blubber was about 90% of that in the whole body. Approximately 90% of the methylmercury in the whole body was in the muscle. The total selenium content in muscle, liver and blubber comprised 67 - 80%of that in the whole body of immature individuals and mature males. The accumulation of selenium in various tissues varied among mature males, pregnant females and lactating females. The con centration ratio of total mercury to selenium was lower in females at the later gestational stage than in mature males, and the ratio was the highest in females at the early gestational stage and lactating females.

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ω-Methyl- 11 -deoxy-7-oxaprostaglandin (5a-t), co-methyl-9, 11-bisdeoxy-7-oxaprostaglandin (6a-t) and their related compounds having a gem-dimethyl, gem-methylethyl, gem-methylpropyl, gem-methylbenzyl or gem-methylallyl group as the ω-chain (5b-5f, 6b-6e) were synthesized starting from cyclotene (1), 2-hydroxy-3-methyl-2-cyclopenten-1 -one, which is a principal constituent of coffee aroma and maple flavor.

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Glucose isomerization, catalyzed by an immobilized enzyme, was analyzed with a first-order rate equation. The overall reaction rate was measured in a batch reaction, and the rate constant and the effectiveness factor could be separated by use of the effective diffusion coefficient determined.
After the enzymatic properties were elucidated, the immobilized glucose isomerase was used in a reactor consisting of zigzag inclined channels. The particles of the immobilized enzyme were fluidized stably at flow velocities of up to one-tenth of the particle terminal velocity. The performance of the fluidized bed reactor was well described by the model of axial dispersion at an intermediate flow velocity, and the attainable degree of isomerization was more than 50%. The conversion, however, became worse at a liquid velocity lower than 0.5 cm/min.

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Amongthe polyphenols found in beer, proanthocyanidins were found to have a specific affinity for the haze-forming proteins in beer and retained their capacity to form a chill haze. Proanthocyanidins pentamer and tetramer had the highest affinities for the haze-forming proteins, followed by the trimer, dimer and catechins. During the brewing process, proanthocyanidin trimer and polymeric proanthocyanidins easily formed insoluble complexes with proteins in the wort as a result of their high affinity for proteins; consequently, these were not found in finished beer, whereas such proanthocyanidin dimers as procyanidin B₃, and catechin survived in finished beer. Procyanidin B₃ and catechin, when stored in beer or a buffer solution, seemed to undergo oxidative polymerization and increased their affinity for the haze-forming proteins to form a extensive chill haze.

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The effects of the colloidal properties of emulsion particles and the conformation of tryptic digests of soybean glycinin, the emulsifiers, on emulsion properties were investigated. Thedigests were separated into some fractions, and the properties of intact glycinin, two kinds of the best were examined. The diameter of the emulsion particles measured by spectroturbidimetry was not very different amongthe best emulsifiers and intact glycinin in spite of the difference in emulsifying ability; however, a new parameter, flocculation strength, which is the rigidity of the flocculated structure and is defined as the minimum detergent concentration for the dissociation offlocculation, closely and negatively related to the short term emulsion stability. The amount of adsorbed protein on the surface of the emulsion particles was also related to the long term emulsion stability. The two best emulsifiers were analyzed by gel filtration and circular dichroism. The emulsifiers contained large molecular componentswhosemolecular weight and secondary structures were similar to intact glycinin. The conformational stability of the emulsifiers was evaluated by the change in emission maximaof the intrinsic fluorescence of the proteins against changing urea concentration, and the surface hydrophobicity of the proteins was estimated by the binding of l-anilino-8- naphthalene sulfonate (ANS). The emulsion stability increased with decreasing conformational stability and increasing surface hydrophobicity of the emulsifier proteins.

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Soluble delipidated granule was fractionated into mainly two components by gel filtration and each component was purified by DEAE-cellulose chromatography. The phosvitins so prepared were designated as phosvitin 1 and phosvitin 2. Phosvitin 1 contained 59.2% serine and 10.2% phosphorus, while phosvitin 2 had 51.5% serine and 8.9% phosphorus. Phosvitin 1 was dissociated into nine protein fractions ranging in molecular weights from 1.33×10⁴-1.36×10⁵ daltons, in the SDS-polyacrylamide gel electrophoretic pattern. On the other hand, Phosvitin 2 was dissociated into thirteen bands ranging in molecular weights from 1.1×10⁴-1.37×10⁵ daltons, in t e SDSpolyacrylamide gel electrophoretic pattern. Onthe contrary, the major component of phosvitin 1 has a molecular weight of 2.29×10⁴ when determined by gel filtration with 6m guanidine hydrochloride, while the major components ofphosvitin 2 have molecular weights of 2.29×10⁴ and 1.0×10⁴. From these results, it seems that phosvitin is composed of several subcomponents.

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A nicotinamide adenine dinucleotide-linked p-hydroxybenzyl alcohol dehydrogenase activity was demonstrated in cells of Rhodopseudomonas acidophila M402 grown on p-hydroxybenzyl alcohol as a major carbon source under anaerobic-light conditions. The enzymewas purified to homogeneity on polyacrylamide gel electrophoresis. The molecular weight of the enzymewas estimated to be 27, 000 dalton by gel filtration and the isoelectric point was pH 7.4. This dehydrogenase requires NAD⁺ as an electron acceptor and has broad specificity for aromatic alcohols. This enzyme is also capable of oxidizing aliphatic primary alcohols with NAD⁺.
While this enzyme was induced by p-hydroxybenzyl alcohol, the final preparation showed the highest affinity for vanillyl and cinnamyl alcohols rather than p-hydroxybenzyl or benzyl alcohols. Para-derivatives (methyl, methoxy, nitro or chloro) of benzyl alcohol also underwent the dehydrogenation reaction. Moreover, the enzyme was also active on m-derivatives (hydroxy, methyl, methoxy, nitro or chloro) of benzyl alcohol, 39 to 55% of the activity seen for p-hydroxybenzyl alcohol. The most interesting characteristic of this dehydrogenase is its wide affinity range for aliphatic alcohols: 1-butanol, 1-pentanol, 3-methyl-l-butanol, 1-hexanol, 1-heptanol, 1- octanol and 1-nonanol. This substrate specificity resembles that of dye-linked alcohol dehydrogenase (PMS-linked vanillyl alcohol dehydrogenase) from the same organism, but the two enzymes differ in their mode of induction, electron acceptor requirement, ammoniumrequirement for activity, pH optima, molecular weight and other aspects. A typical NAD⁺-dependent alcohol dehydrogenase oxidizes ethanol and other primary alcohols, and acetaldehyde, but not methanol or aromatic alcohols such as benzyl alcohol, hydroxybenzyl alcohol and vanillyl alcohol. Therefore, the p-hydroxybenzyl alcohol dehydrogenase reported in this paper is a new type of alcohol dehydrogenase which is different from hitherto reported alcohol dehydrogenases.

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Enzymatic synthesis of α-glucosyl-sucrose through the transglucosidase action of immobilized buckwheat α-gl cosidase was attempted in a reaction system containing maltose and sucrose. Three kinds of nonreducing trisaccharides were produced, and a large portion of the trisaccharide was 4^G- α-D-glucosyl-sucrose (erlose). Another was a new trisaccharide, O-α-D-glucopyranosyl-(1→3)-O-α-D-glucopyranosyl-(1→2)-O-β-D-fructofuranoside (3^G-α-D-glucosyl-sucrose; [α]_D+120°, in water), and the other was 6^G-α-D-glucosyl-sucrose (theanderose; [α]_D+ 107°, in water). The new trisaccharide was named "esculose."

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Methyl viologen-linked nitrite reductase (EC 1.7.7. 1), an enzyme which catalyzes the 6-electron reduction of nitrite to ammonia, was isolated from bean roots. The isolated enzyme was homogeneous by disc electrophoresis with polyacrylamide gel. The molecular weight of the enzyme was estimated to be 62, 000 by SDS-polyacrylamide gel electrophoresis. In the oxidized form, the enzyme had absorption maxima at 280, 397 (Soret band), 535, and 573 nm (α band), indicating that siroheme is directly involved in the catalysis of nitrite reduction. The absorbance ratios, A₃₉₁ : A₂₈₀ and A₅₇₃ : A₃₉₇, were 0.3 and 0.39, respectively. Antiserum to spinach leafnitrite reductase failed to give a positive Ouchterlony result with bean root nitrite reductase, but this antiserum did inhibit the activity of the latter enzyme.

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A pyruvate kinase-lacking mutant of Brevibacteriumflavum produced 22.6 g/liter of L-aspartic acid with glutamic acid as a by-product, when cultured for 48 hr in a medium containing 100 g/litei of glucose. The production clearly depended on the amount of biotin added. This strain, 70, was derived by several steps of mutation from wild strain 2247 producing glutamate, successively via a citrate synthase-defective glutamate auxotroph, strain 214, a prototrophic revertant, strain 15-8 producing 10 g/liter of L-aspartic acid, and an S-(2-aminoethyl)-L-cysteine-resistant mutant, strair 1-231, having low pyruvate kinase and homoserine dehydrogenase and producing lysine. Strain 70. amethionine-insensitive revertant from strain 1-231, had a normal level of homoserine dehydrogenase but no pyruvate kinase. Its citrate synthase activity was about half that of the wild strain at saturated concentrations of the substrates with Michaelis constants for oxalacetate and acetyl- GoA of 1 10 and 6 times as high as those of the wild-type enzyme, respectively. The mutational step for these alterations in citrate synthase was strain 15-8. Phosphoenolpyruvate carboxylase of strain 70 showed 1.5-fold higher activity in the crude extract at saturated concentrations of phosphoenolpyruvate, a lower Michaelis constant (1.5mM). for the substrate, phosphoenolpyruvate, less sensitivity to the feedback inhibition by aspartate, and higher sensitivities to the activators, acetyl- CoA and fructose-1, 6-bisphosphate, than those of the wild strain. The concentrations of aspartate giving 50% inhibition were 6.2- and 4.5-fold higher in the absence and presence of acetyl-CoA. respectively.

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In order to easily prepare water-soluble polymers and oligomers investigated the optimum conditions under which kaki-tannin, purified from young and immature persimmon fruit, could be treated with a polyphenol in acidic solvents. Finally, we established the following conditions; ethanol containing 0.5 M acetic acid or formic acid is used as a solvent, the ratio ofphloroglucinol to kaki-tannin is 1 to 1, the tannin concentration is about 0.2 to 1.0%, and the incubation is performed with refluxing under a nitrogen stream. Then, various polymers and oligomers can be prepared by changing the incubation time (for example, 3 to 50 hr).
Four polyphenolic degradates were isolated from kaki-tannin after such phloroglucinol treatment of longer duration. Their chemical structures suggested that phloroglucinol acts as a unitcatching agent in the reaction, as well as toluene-α-thiol.

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When yeast protoplasts that were producing repressible acid phosphatase (r-APase) were treated with tunicamycin (TM), three specific proteins of 59k, 57k, and 55k daltons were accumulated in the membrane fraction in addition to the usual membrane proteins and these proteins were not detected in the secreted fraction. These proteins were immunoprecipitated with anti r-APase antiserum. Their molecular sizes were almost the same as those endo-H treated r- APase. Therefore these proteins were considered to be nonglycosylated forms of r-APase proteins. These results proved that nonglycosylated forms of r-APase produced by TM-treatment were not secreted by yeast protoplasts.

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(+)-Marmelo Lactones A (VA) and B (VB) were synthesized from erythro-γ-methyl-L-glutamic acid (IA) and threo acid (IB), respectively. The absolute configurations of natural marmelo lactones were thus determined to be (2R, 4S) for (+)-marmelo lactone A and (2R, 4R) for (-)-marmelo lactone B.

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(+)-Marmelo oxide A and (-)-marmelo oxide B were stereoselectively synthesized from dglutamic acid via (-)-marmelo lactones A and B. The absolute configurations of marmleooxides were thus determined to be the (+)-oxide A having the (2R, 4R) and (+)-oxide B having (2S, 4R) configurations.

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Weselected Streptomyces cellulosae bacause it secreted an unusual protease into the culture broth. The protease formed more turbidity in a 16% soybean protein hydrolysate in the initial stage of the reaction than α-chymotrypsin did, when the proteolytic activity of the protease was same as that of α-chymotrypsin. The protease was purified 564-fold from culture broth in 5.8% yield. The precipitated product from the soybean protein hydrolysate was a protein-like compoundcontaining mainly hydrophobic amino acids.

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The protease from Streptomyces cellulosae formed more turbidity in a 16% soybean protein hydrolysate in the initial stage of the reaction than α-chymotrypsin did, when the proteolytic activity of the protease was same as that of α-chymotrypsin. In highly concentrated solutions (2.5%) of various dipeptides, oligopeptides were produced by condensation by the protease. The oligopeptides formed were (L-Leu-Gly)₂ and (L-Leu-Gly)₃ from L-Leu-Gly, (L-Phe-L-Val)₂ from L-Phe-LVal, (L-Val-L-Phe)₂ and (L-Val-L-Phe)₃ from L-Val-L-Phe, and (L-Leu-L-Met)₂ and (L-Leu-L-Met)₃ from L-Leu-L-Met.

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Lysate of chloroplasts prepared from liverwort Marchantia polymorpha L. cell suspension cultures incorporated [³H]-dTTP into acid insoluble materials when DNA was added exogenously as a template. The incorporation was highly dependent on the addition of template DNA, four deoxynucleoside triphosphates and magnesium ions (maximum incorporation at 5mM). Magnesium ions could be replaced by manganese ions. DNA synthesis inhibitors, Nethylmaleimide (NEM) and ethidium bromide (EtBr), strongly inhibited the incorporation. Dideoxythymidine triphosphate (ddTTP), an inhibitor of DNA polymerases β and γ, inhibited the incorporation at the concentration of 50μM (molar ratio of ddTTP/dTTP= 17). On the other hand, the incorporation by the chloroplast lysate was resistant to arabinofuranosyl cytosine triphosphate (araCTP) and aphidicolin as well as the RNA polymerase inhibitors, rifampicin and α-amanitin. The chloroplast lysate highly utilized denatured calf thymus DNA and bacteriophage ΦX174 singlestranded DNA as templates when added exogenously, while a synthetic homopolymer, poly(rA)- oligo(dT)_12-18, did not stimulate the incorporation at all. Autoradiographic analysis of DNA synthesized in isolated chloroplasts showed that the chloroplast DNA synthesis took place at several specific sites on the chloroplast DNA from cells of the liverwort, Marchantia polymorpha.

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We described product analysis of DNA synthesized in chloroplast lysate from liverwort Marchantia polymorpha L. cell suspension cultures. Characteristics of in vitro DNA synthesis by chloroplast lysate using bacteriophage ΦX174 single-stranded DNA were very similar to those in the case of double-stranded calf thymus DNA reported previously. Autoradiographic analysis clearly showed the incorporation of radioactive [α-³²P]-dCTP into DNA molecules associated with bacteriophage ΦX174 single-stranded template DNA, indicating conversion of bacteriophage ΦX174 single-stranded DNA to double-stranded DNA(RF III, double-stranded linear molecule). Experiments on the fate of [³²P]-labeled single-stranded DNA also showeda clear conversion of the single-stranded DNA to double-stranded DNA. Furthermore, patterns of sucrose density gradient centrifugations (neutral and alkaline) showed the production of two major components in in vitro DNA synthesis by chloroplast lysate. This also indicated conversion of bacteriophage ΦX174 single-stranded DNA to double-stranded DNA (RF III form). Our results suggest that the mechanism of chloroplast DNA replication could be the mode of strand-displacement DNA synthesis as seen in animal mitochondrial DNA synthesis.

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N-Acyl α, β-dehydroalanines (1) were synthesized from the corresponding N-acyl aspartic acids by a one-pot procedure through a biomimetic oxidative β-decarboxylation. In particular, the transformation using methanol-sodium hypochlorite aqueous solution, which served for N-chlorination and dehydrochlorination, afforded good yields of (1).

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The following properties of food proteins polymerized by guinea pig liver transglutaminase were investigated: (1) solubility, (2) emulsifying activity and emulsion stability, and (3) un frozen water content by pulsed NMR. Several food proteins (α_sl- and κ-caseins, and soybean 7S and 11S globulins) were polymerized by this enzyme. Solubility and emulsifying activity of polymerized α_sl-casein were higher than those of the native protein in the range of pH4-6. Unfrozen water contents of polymerized soybean globulins were muchhigher than those of the native proteins. These results suggest that transglutaminase treatment maybe used for the production of newfood protein material with higher hydration ability.

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Higher homologs of lysine derivatives consisting of L-lysine and dicarboxylic acids were synthesized. The acids ranged from carbon atoms C₁₁ to C₁₇ and C₂₀ and were coupled with ε-benzyloxycarbonyl- lysine ethyl ester (Lys (Z)-OEt) by conventional methods of peptide synthesis. The removal of the Z-group from the protected compounds by hydrogenation gave the final products as bifunctional agents: undecanedioyl-Lys-OEt, dodecanedioyl-Lys-OEt, tridecanedioyl- Lys-OEt, tetradecanedioyl-Lys-OEt, pentadecanedioyl-Lys-OEt, hexadecanedioyl-Lys-OEt, heptadecanedioyl-Lys-OEt and eicosanedioyl-Lys-OEt. All the products showed a greater inactivating effect on several phages than azelaoyl-Lys-OEt, which showed the highest phageinactivating effect amongthe compoundsreported in our previous paper.

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Twoindole alkaloids which induce the Epstein-Barr virus early antigen of Raji cells (B lymphocyte) were found in the cultured broth of Actinomycetes NA34-17, from which teleocidin B was also obtained. The active compoundsisolated were identified from their spectral data and chemical evidence as (-)-indolactam V and (-)-14-O-acetyl indolactam V.

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Phosphatidylethanolamine (PE) is generally more oxidizable than phosphatidylcholine (PC). To determine the difference in reactivities to oxidation between PE and PC, it is necessary for their fatty acid moieties to be uniform. Experimental results of the ferrous ion-catalyzed oxidation of dilinoleoylphosphatidylcholine, dilinoleoylphosphatidylethanolamine, and dilinoleoyldiglyceride revealed that the rate of oxidation depends on the type of base. Ferrous ion possessed a high catalytic activity in hydroperoxide formation at pH 5.8. Iron ions might initiate the oxidation of phospholipids by forming free radicals. Phosphoethanolamine was capable of trapping ferrous ion and preventing it from being autoxidized to ferric ion. Trapping of ferrous ion might be responsible for the significant oxidizability of PE at pH 5.8-7.0. In the ferrous ion-ascorbic acid (AsA) catalyzed oxidation system, PC oxidation was remarkably enhanced at pH 7.0. In this case, no reduction of ferric ion occurred, but AsA had a prooxidant effect of accelerating the formation of free radicals.

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The main subunits of glutenin were separated by preparative SDS-PAGE with a Laemmli system (U. K. Laemmli, Nature, 227, 680 (1970)) and their cysteine (Cys) contents were determined by amino acid analysis. Aminoacid compositions of glutenin subunits, determined in the present study, were different from those determined by Danno et al. [G. Danno, K. Kanazawa and M. Natake, Agric. Biol. Chem., 40, 739 (1976)]. Wefound that these differences were due to the different methods of hydrolysis of subunit polypeptides. That is, hydrolysis of subunit polypeptides extracted from gel and hydrolysis of polypeptides in gel without extraction. Cys contents of glutenin subunits were determined as S-pyridylethyl cysteine (PE-Cys). Although no PE-Cys was detected in B-4 or B-4', all other subunits were shown to have 4mol Cys per mol protein, respectively.

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Talopeptin (N-(6-deoxy-α-L-talopyranosyloxyphospho)-L-leucyl-L-tryptophan), a specific inhibitor for thermolysin and some other endo-type metalloproteases, does not inhibit superoxide dismutase, alkaline phosphatase, or carbonic anhydrase, which are Zn(II)-enzymes, in the inhibitor concentration of the order of 10^-4M. Although the enzyme activity of carboxypeptidase A, a Zn(II)-containing exo-type metalloprotease, is slightly reduced by the addition of talopeptin, the inhibition is not significant at the 10% leveljudged by Student's t test. On the other hand, talopeptin seemed to act as an inhibitor for all dehydrogenases examined, most of which do not contain Zn(II), at the inhibitor concentration studied (around 10^-4m). It is possible that the phosphite group of talopeptin binds to the same site on the dehydrogenase as the one for the phosphate group of the coenzyme.

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Fresh rice grains stored under anaerobic conditions at 4°C showed a strong activity of anaerobic respiration at 30°C. Whenstored at 30°C, the rates of both oxygen consumption and carbon dioxide evolution declined rapidly. The ethanol content in paddy at the post-harvest stage was increased at 4°C, whereas no significant accumulation of ethanol was observed at 30°C. The accumulated ethanol in paddy was depleted as the storage temperature was raised from 4 to 30°C. In contrast, a temperature-dependent accumulation was observed with a lowering from 30 to 4°C. On the other hand, ethanol content in brown rice changed little with storage temperature. On the basis of these results, it is assumed that ethanol is more easily accumulated in the rice grains against diffusion to the atmosphere at the lower temperature.

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An adenosine-sensitive mutant was isolated from Escherichia coli K12 derivative strain C600. This mutant (designated as PS100) grew slower than parental strain C600 in a minimal medium, and its growth was completely inhibited by addition of all kinds of purine bases, nucleosides and nucleotides tested. On the other hand, this growth inhibitory effect of purine derivatives was reversed by co-addition of uridine to the medium. Other pyrimidine derivatives such as uracil, UMP, cytosine, cytidine, CMPand thymidine were also effective for this reversal. The mutant strain, PS100, showed a lower level (7%) of activity for orotate phosphoribosyltransferase than strain C600 did, and accumulated orotic acid in the growth medium. Lysogenization of strain PS100 with λ transducing phage containing the gene for orotate phosphoribosyltransferase (pyrE) resulted in restoration of the activity for orotate phosphoribosyltransferase and removal of growth inhibition by purine derivatives.

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Excretion of intracellular 5'-inosinic acid (5'-IMP) of a series of mutants of Brevibacterium ammoniagenes selected for high 5'-IMP productivity was measured by incubating the washed cells in a phosphate buffer at 30°C. In the highest producer, KY13369, intracellular 5'-IMP was excreted partly as 5'-IMP and partly as hypoxanthine (Hx), after degradation, to the outside, which indicates the existence of two excretion systems of intracellular 5'-IMP. One is a direct excretion system of 5'-IMP and the other is an indirect excretion system coupled with degradation. 5'-IMP accumulation via the direct excretion system by the washed cells was stimulated by various energy sources and was completely inhibited by KCN, NaN₃, DNPand CCCP, providing the evidence that excretion of intracellular 5'-IMP is dependent on energy-yielding reactions. The increased 5'-IMP productivity of KY13369 can be ascribed to the increased direct excretion system and to the changes of the indirect excretion system, which was more susceptible to glucose inhibition.

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α-Galactosidase (EC 3.2. 1.22) from Pycnoporus cinnabarinus was purified by precipitation with ammoniumsulfate, column chromatographies on DEAE-SephadexA-50, Sephadex G-100, CMS ephadex C-50, and SP-Sephadex C-50, and isoelectric focusing. The purified enzyme was homogeneous on polyacrylamide disc gel electrophoresis, and the molecular weight was estimated to be about 210, 000 by gel filtration on Sephacryl S-200 and about 52, 000 by sodium dodecyl sulfate gel electrophoresis. The enzyme exhibited the optimum pH at 5.0 and was stable between pH 3 and 9. The optimumtemperature of the enzyme was 75°C. The enzymewas thermostable at pH 5.0 and completely lost its activity after heating at 90°C or at pH 3.5. The Michaelis constants were 0.31 mM for p-nitrophenyl α-D-galactoside, 0.80mM for melibiose, 2.16mM for raffinose, and 1.15mM for stachyose. The α-galactosidase activity was strongly inhibited by Ag⁺, Hg⁺⁺, p-chloromercuribenzoate, galactose, and melibiose. The enzyme also seemed to catalyse a glycosyltransfer reaction.

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Retting is an application of microbial degradation of pectic substances contained in pectocellulosic fibers and is closely related to plant tissue maceration by pectic enzymes, especially to those plant diseases called" rot." ^1-3) As microorganisms secreting pectic enzymes, the genera Bacillus, Clostridium, Erwinia, and others are well known. ⁴⁾ Among them Erwinia has reported to be one of the strongest soft rot pathogens. The lants parasitized by Erwinia extend from annual and perennial vegetables, special crops, and petals to woody plants such as mulberry shoots. ⁵⁾ Previous work^{6, 7)} in this series has shown that retting with alkalophilic Bacillus sp. appreciably improved the pulping rate, but it had a limitation. In the present paper another investigation was made of retting of the inner bark of kozo or paper mulberry (Broussonetia kazinoki Sieb.) with E. carotovora to further accelerate pulping rate, considering that kozo in the mulberry family (Moraceae).

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