Abstract: N-Acetylmannosamine dehydrogenase which takes off hydrogen from N-acetylmannosamine to convert it into N-acetylmannosaminolactone and, at the same time, reduces coenzyme NAD into NADH. This enzyme can be obtained by culturing, in a medium, a strain belonging to Genus Flavobacterium and having an ability to produce N-acetylmannosamine dehydrogenase producing activity, and then collecting it. This enzyme is usable in the quantitative analysis of N-acetylmannosamine or sialic acid.

Abstract: A bacteriophage which is characterized by the presence of one or more restriction enzyme sites downstream from the late promoter up to the cohesive end, and none or a permissible number of restriction enzyme sites upstream from the late promoter to the cohesive end is useful as an expression vector. The vector can be used to obtain high expression of DNA inserted at the restriction enzyme site downstream from the late promoter up to the cohesive end.

Abstract: When a microorganism belonging to the genus Bacillus and capable of producing heat-resistant sarcosine oxidase N is cultured in a medium, there can be obtained from the cultured medium, heat-resistant sarcosine oxidase N having the following physico-chemical properties:(a) ActionSarcosine oxidase N catalyses the following enzyme reaction wherein sarcosine is oxidatively decomposed to form glycine, formaldehyde and hydrogen peroxide.Sarcosine+H.sub.2 O+O.sub.2 .fwdarw.glycine+formaldehyde+H.sub.2 O.sub.2(b) Substrate specificitySarcosine oxidase N has a Km value (Michaelis constant) for sarcosine of 4.7 mM at 37.degree. C. at pH 7.7 (phosphate buffer solution).(c) Optimum pH and stable pH rangeThe optimum pH of sarcosine oxidase N is 6.7 to 10.0 when sarcosine is used as a substrate.The stable pH range is 6.5 to 11.5.(d) Optimum temperature range45.degree. to 60.degree. C.(e) Heat stabilitySarcosine oxidase N retains its enzymatic activity of 98% when treated at 55.degree. C.

Abstract: A method for quantitative determination of N-acetylhexosamine which comprises (a) allowing an N-acetylhexosamine oxidase to act upon an N-acetylhexosamine-containing liquid in the presence of oxygen and then (b) determining the amount of oxygen consumed in the oxidation reaction or the amount of hydrogen peroxide or N-acetylhexaminic acid formed in the oxidation reaction. Further, a reagent for quantitative determination of N-acetylhexosamine, characterized by containing an N-acetylhexosamine oxidase.

Abstract: An N-acetylhexosamine oxidase having the following physiochemical properties.(1) Action and specificity for substrateOxidizes N-acetylhexosamine in the presence of oxygen to form N-acetylhexosaminic acid and hydrogen peroxide. Hardly acts or does not act at all on hexose and hexosamine.(2) Optimum pH and stable pH rangeWhen a potassium phosphate buffer solution contining 0.1M glycine is used, an optimum pH is 7.5 to 8.5 and a stable pH range is 3 to 9.(3) Molecular weightHas a molecular weight of about 140,000 to 150,000 when measured according to a gel filtration method using Sephadex G-200 by the use of 0.05M potassium phosphate buffer solution.

Abstract: A method for the assay of .alpha.-amylase activity, which comprises adding an .alpha.-amylase-containing sample to maltohexaitol or maltohexaonic acid used as substrate, reacting, at the same time or subsequent to the addition, .alpha.-glucosidase with the resulting mixture, and determining the reaction product to assay the .alpha.-amylase activity.

Abstract: A method for the preparation of a novel recombinant DNA, which comprises (1) cleaving with an endonuclease a temperate phage DNA having an endonuclease-sensitive region not in the DNA segment participating in the replication of phage DNA and the integration of phage DNA into a host chromosome but at least in the DNA segment carrying genetic information for the coat protein production and another DNA carrying intended genetic information, (2) adding DNA-ligase to the mixture of both cleft DNA's, and (3) recovering from the mixture a phage DNA having its coat protein producing ability deleted by the replacement of the DNA segments carrying genetic information for the coat protein production with a DNA fragment carrying the intended information.

Abstract: A method for preparing a novel recombinant DNA, which comprises (1) cleaving with an endonuclease a phage DNA having an endonuclease-sensitive region not in the DNA segment participating in temperate phage DNA replication and integration of DNA into a host chromosome but in other DNA segments, a temperate phage DNA having an endonuclease-sensitive region in the DNA segment carrying genetic information for the production of coat protein, and a DNA carrying the intended genetic information, (2) mixing together all fragments produced by said cleaving, (3) adding DNA ligase to the mixture, and (4) recovering from the resulting mixture a phage DNA having its coat protein producing ability deleted by the replacement of the DNA segment carrying genetic information for coat protein production with a DNA fragment carrying the intended genetic information.

Abstract: A novel bacteriophage whose DNA molecule has endonuclease-sensitivity only in the DNA region carrying genetic information for the production of phage coat proteins can be obtained by isolating an endonuclease-resistant mutant from one of the lambdoid bacteriophages and mating the resulting bacteriophage with a lambdoid phage having endonuclease-sensitivity in the DNA region carrying genetic information for the production of coat proteins.

Abstract: 5-Isopropyl-8-methyl bicyclo[5.3.0]deca-2,8-diene-2-carboxylic acid having a chemical structure represented by the following formula: ##STR1## and 5-isopropyl-8-methyl bicyclo[5.3.0]deca-2,8-diene-2-carboaldehyde having a chemical structure represented by the following formula: ##STR2## can be obtained by cultivating a microbial strain belonging to Genus Sclerotinia and having an ability to produce them, and collecting them from the cultivated mixture.

Abstract: 5-Isopropyl-8-methyl bicyclo[5.3.0]deca-2,8-diene-2-carboxylic acid having a chemical structure represented by the following formula: ##STR1## and 5-isopropyl-8-methyl bicyclo[5.3.0]deca-2,8-diene-2-carboaldehyde having a chemical structure represented by the following formula: ##STR2## can be obtained by cultivating a microbial strain belonging to Genus Sclerotinia and having an ability to produce them, and collecting them from the cultivated mixture.

Abstract: 5-Isopropyl-8-methyl bicyclo[5.3.0]deca-2,8-diene-2-carboxylic acid having a chemical structure represented by the following formula: ##STR1## and 5-isopropyl-8-methyl bicyclo[5.3.0]deca-2,8-diene-2-carboaldehyde having a chemical structure represented by the following formula: ##STR2## can be obtained by cultivating a microbial strain belonging to Genus Sclerotinia and having an ability to produce them, and collecting them from the cultivated mixture.

Abstract: The improvement in a process for the production of 17-hydroxyandrosta-1,4-dien-3-one and androsta-1,4-diene-3,17-dione by the microbiological oxidation of a sterol, its 4-en-3-one derivative or its 1,4-dien-3-one derivative, which comprises adding to the culture medium at least one glyceride-containing substance selected from the group consisting of glycerides, fats, oil seeds and oil fruits in an amount sufficient that the culture medium contains at least 0.3 percent by weight of glycerides.

Abstract: Creatinine amidohydrolase and creatine amidinohydrolase can be obtained by culturing a strain belonging to Genus Flavobacterium, Genus Micrococcus or Genus Corynebacterium and having an ability to produce creatinine amidohydrolase and creatine amidinohydrolase in the presence of creatinine, creatine or a mixture thereof and separating creatinine amidohydrolase and creatine amidinohydrolase from the cultured fluid.