The measurement of N-acetyl-β-glucosaminidase activity upon β-MAGA^* was carried out in order to survey oligosaccharidase fraction in the chitinolytic enzymes of Aspergillus niger. N-Acetyl-β-glucosaminidase was purified in parallel with chitobiase activity, being separated from chitinase activity, and some properties of the enzyme in the hydrolysis of β-MAGA and DACB were investigated. The enzyme hydrolysed more rapidly β-glucosaminidic bonds in DACB than that in β-MAGA, but did not decompose α-MAGA.

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During the study on the sugar metabolism of molds, several strains of Pullularia pullulans were found to produce large amounts of gluconic acid from glucose. Thirty seven strains of P. pullulans were then tested for their acid-producing abilities. Seven strains did not produce any amount of gluconic acid. However, all of the other strains were shown to be capable of producing this acid. The superior strains produced yields of gluconic acid as high as about 90%, based on glucose available, in shaking cultures at 30°C after 2 days. The yields were increased up to approximately 100% during later stages. In addition to high yields, gluconic acid was produced exclusively by these strains. Glutamic acid and inorganic ammonium salts, such as (NH₄)₂SO₄, NH₄Cl and (NH₄)₂HP0₄, were favorable nitrogen sources for acid production. In the case of (NH₄)₂SO₄, the optimum concentration was 0.05%. The addition of CaCO₃ was essential for gluconic acid production by P. pullulans and a 3% concentration of CaCO₃ appeared to be desirable for the maximum conversion to gluconic acid in a medium containing 10% glucose.

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Two pectinesterases (PE), PE I and II, have been separated from culture extract of Coniothyrium diplodiella by chromatographies on Duolite A-2 and DEAE-cellulose. The purified PEs were homogeneous on free-boundary electrophoresis. The enzymes were stable below 40°C but lost their activities completely at 55°C in 10 minutes. The enzymes were most active in the pG range of 4.5_??_5.0. NaCl, CaCl₂ and other mono- and divalent cations stimulated the enzymes, but tei- and tetravalent cations (FeCl₃, SnCl₄, inhibited the enzyme action of the PEs. Both PE I etc.) pectin and II hydrolyzed methyl ester groups of (esterification degree 64%) to the 60% level. No significant difference was observed between PE I and II, except that the stable pH ranges of PE I and II were 4.0_??_5.5 and 4.0_??_5.0, respectively.

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Metal ions had little influence on riboflavin production by Candida robusta, except that Ag, Cu and Hg were strongly inhibitory. The inhibiting action of iron on its production was comparatively small, so that any previous treatment for the removal of iron from the medium was not necessary. Addition of CaCO3 was found to be essential in media containing sucrose or acetate as a carbon source, as pointed out in the previous paper.¹⁾ This effect of CaCO₃ was attributed to its neutralizing action. When the reaction of the medium was kept at the optimum pH, about 7.0, high yields of riboflavin could be obtained without the presence of CaCO₃.

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A wood-destroying fungus, Trametes sanguinea, produced a potent acid protease in a submerged culture. Maximum proteolytic activity of the culture was attained after 140-hours cultivation in a medium containing dextrin and corn steep liquor. The acid protease was obtained in crystalline form from the mycelium-free culture filtrate by the following successive treatments: acetone precipitation, ionexchange column chromatography, ammonium sulfate fractionation, dialysis, and crystallization by acetone. Throughout the over-all process, the acid protease was purified approximately 30-fold with about 8% recovery of the original activity.

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The crystalline enzyme of Trametes sanguinea has been proved homopeneous by chromatography, electrophoresis and ultra-centrifugal analysis. The molecular weight of the enzyme was found to be about 34, 000 and the iso-electric point to be pH 3.5. The enzyme activities are found favorable within the range of pH 2.3_??_2.5 and at temperatures around 55°C. The enzyme is stable at pH 2_??_6 and completely inactivated by heating at 70°C for 10mins.

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(1) Cloudy apple juice could be clarified by ultracentrifugation, e.g., 75, 000g for 30 minutes, without using pectic enzymes. The ultracentrifugal precipitates were readily ablt to be resuspended in water or in other aqueous solutions, resulting in stable suspensions. These suspensions were regarded as simplified models for apple juice.
(2) Any notable difference was not found between the enzymic and ultracentrifugal precipitates in relation to dry matter weight, elementary composition, ash, amino acid and sugar compositions. Both precipitates were found to contain about 36% of protein.
(3) The enzymic clarificaion reaction was observed below pH 4.75, but not above pH 4.75 in the cased of apple juice and the re-suspensions.
(4) Judging from the interactions with other colloids and the results of electrophoresis, the surface of the suspended materials in apple juice was thought to be negatively charged.
(5) The enzymic clarification reaction in the re-suspension systems was markedly accelerated by the addition of a small amount of protein.
(6) Negatively charged molecular colloids, such as sodium alginated or carboxymethyl cellulose even at the low concentration, completely inhibited the clarificaion reaction.
(7) From the electrostatical and colloidal points of view, a supposed mechanism of the flocculation of the suspended materials was presented.

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3β-Acetoxy-B-nor-5β-cholestan-6-one (Ia) afforded only one isolatable oxime (IIa), while oximation of 3β, 17β-diacetoxy-B-nor-5β-androstan-6-one (Ib) yielded two isomeric oximes (IIb and IIIb). 7-Aza-5β-cholestan-3β-ol (VIa), 7-aza-5β-androstane-3β, 17β-diol (VIc), and 6-aza-5β-androstane-3β, 17β-diol (VIIc) were synthesized by Bechmann rearrangement of these oximes, followed by reduction with lithium aluminium hydride. The structure of the aza-steroids were established by conversion of the intermediate lactams (IVa, b) into the lactones (IXa, b), prepared from the 3β-acetoxy-B-nor-6-oxo-5β-steroids (Ia, b) by Baeyer Villiger reaction.

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3β-Hydroxy-6- and 7-aza-5α-steroids in the cholestane and androstanze series were synthesized by oximination of 3β-acetoxy-B-nor-5α-cholestan-6-one and 3β, 17β-diacetoxy-B-nor-5α-androstan-6-one, followed by Beckmann rearrangement and reduction with lithium aluminium hydride.

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1. It was confirmed that washed yeast cells produced active amyl alcohol and n-butanol from oxalacetic acid, aspartic acid, homoserine of HAB. At the same time α-keto-β-methyl-n valeric acid was formed.
2. These results strengthen the reliability of the presumptive scheme of the formation of active amyl alcohol proposed by us.
3. Acetylpropionyl and 2, 3-pentanediol were formed from HAB.

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