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Effect of ethanol gas on the growth of microorganisms
J. FERMENT. BIOENG.,
Abstracts of the Articles Printed in Hakkokogaku Kaishi V o l . 70, N o . 2 (1992)
Effect of Ethanol Gas on the Growth of Microorganisms. MASARUYAMASHITA,*TATSUYA ITO, and I-Imosm MtrRASE (Depart-
ment of Agricultural Chemistry, Faculty of Agriculture, Meijo University, 1-501, Shiogamaguchi, Tenpaku-ku, Nagoya 468) Hakkokogaku 70: 101-107. 1992. The effect of ethanol gas on the growth of microorganisms was tested in a small glass vessel. With ethanol gas alone growth inhibition of the microorganisms could not be observed, but with ethanol gas and glycerol growth of the microorganisms was inhibited. After the ethanol gas test, about 80°~ of the ethanol was absorbed in the agar medium and the ethanol in the vessel air was about 1/200-1/1000 of that in the medium. From inhibition tests with different volumes of agar medium, we concluded that growth inhibition of microorganisms with ethanol gas was mainly due to the ethanol absorbed in the medium and not to that in the vessel air. Ethanol absorption into the agar medium was found to be a fairly lengthy process, and the ethanol content in the medium came to equilibrium only after 2-3 d. The low ethanol content in the agar medium during the initial 2 d allowed cells to grow when ethanol gas alone was added. Glycerol added with ethanol gas seemed to contribute to the inhibition of microbial growth during the initial period. The addition of glucose, Polypepton and starch to the agar medium accelerated the transfer of ethanol into the medium at high ethanol concentrations. These results indicate that studies on the relationship between food components and ethanol absorption into the food are important in terms of food preservation with ethanol gas. * Corresponding author. Purification of Xylanase from Chaetomium gracile Mutant 1161 and Its Xylobiose-Forming Properties. - - N o t e - Tosmo Is.m,'* TETSUYA KONISHI,I TOSmAK~ KUTSUNA,1 KUNIMASA KOGA,2 and TosHrrux.x NAKADA3 (Shin-Nihon Chemical Co. Ltd.,
Showa-cho, Anjyo-shi, Aichi 446, ~Suntory Ltd., Kioi-cho, Chiyodaku, Tokyo 102,2 and Hitachi Zosen Corporation, Sakurajima, Konohana-ku, Osaka 554a) Hakkokogaku 70: 109-114. 1992.
Genetic Organization of the Enzymes Responsible for Degradation of Nylon Oligomers. --Monograph-SEre NEOORO(Department of Biotechnology, Faculty of Engineering, Osaka University, Yamada-oka, Suita-shi, Osaka 565) Hakkokogaku 70: 115-131. 1992. (i) 6-Aminohexanoate-cyclic-dimer hydrolase (EI), exotype 6aminohexanoate-oligomer hydrolase (Eli), and endotype 6-aminohexanoate-oligomer hydrolase (EIII) were found to be responsible for Flavobacterium sp. KI72 degrading 6-aminohexanoate-oligomers, byproducts of nylon-6 manufacture. (ii) The genes for the EI (F-nylA), EII (F-nylB), and EIII (nylC) were encoded on pOAD2, one of the three plasmids harbored in Flavobacterium sp. K172. This plasmid contains two repeated sequences, RS-I and RS-II; one of the two RSiI regions, RS-IIA, contains the F-nylB gene, while the other, RS-IIB, contains the homologous EII' gene (nylB). The F-nylB and nylB" have 88% similarity in their nucleotide sequences, an open reading frame encoding a polypeptide of 392 amino acids. Catalytic activity of the EII' protein toward 6-aminohexanoate-dimer was approximately 0.5% of that of the EII enzyme. (iii) Construction of various hybrid genes obtained by exchanging fragments flanked by conserved restriction sites of the F-nylB and nylB' genes demonstrated that two amino acid replacements in the EI I' enzyme, i.e. Gly 181-+Asp (EII type) and His266--+Asn (EII type), enhanced the activity toward 6-aminohexanoate-dimer 200 fold. (iv) The EI and EII enzymes were found in another 6-aminohexanoate-cyclic dimer degrading bacterium, Pseudomonas sp. NK87. The El gene (P-nylA) and EII gene (P-nylB) of NK87 strain were located on the 23-kilo-base pairs (kbp) and 80kbp plasmids, respectively. The F-nylA and P-nylA genes encoded polypeptide of 493 amino acids and had l0 base substitutions in the coding region. In contrast to the high homology of the nylA genes, the F-nylB and P-nyIB genes had only 55°~ similarity in the nucleotide sequences, and 35~ similarity in the deduced amino acid sequences. On the basis of the structure of nylA, nylB and nylC genes, we discussed how nylon oligomer degradation genes were evolved. Discussion of the Origin of Ancient Japanese Sake: Sake Brewing by Means of Chewing and Sprouting. --Miscellany-SEn~osur~ UEDA (Department of Applied Microbiology, Kumamoto Institute of Technology, Ikeda 4-22-1, Kumamoto 860) Hakkokogaku 70: 133-137. 1992. From a study of various records, the author suggests that Japanese sake may have originated as follows. The Jyomon people --the first inhabitants of Japan-- were taught sake brewing by means of chewing rice by the non-Chinese people who crossed the East China Sea to Japan from the southern part of China in the 5th century BC. Later, the Yayoi people --Chinese people who came from China or Korea to Japan-- taught the Japanese people sake brewing by means of sprouted rice in the 2nd-4th century AD. From the 4th to the 9th centuries AD, the sprouted rice saccharifying agent was improved through adding sprouted rice infected by Aspergillus oryzae to steamed rice infected by A. oryzae, that is koji.
A xylanase (CG) from a solid-state wheat-bran culture of
Chaetomium gracile Mutant 1161 was purified by ethanol fractionation and CM-Sepharose CL-6B column chromatography. The purified CG was found to be homogenous on PAGE. The molecular weight was estimated to be 11,000 by Sephadex G-75 gel filtration, 19,000 by SDS-PAGE. 8 M Urca-SDS-PAGE showed that this enzyme consisted of two subunits of 14,400 and 4,800. The isoelectric point was 8.35. The enzyme was inactivated by NBS, SDS, PCMB, and HgC12. The maximum xylobiose (X2)-forming activity (ability) was shown at pH 5.0 and 50°C; pH and thermal stability ranges were at pHs 4.0--7.0 and up to 45°C. The purified CG could not hydrolyze X2. From an analysis of the bond cleavage of xylooligosaccharidealditols, it was found that the first bond from the non-reducing end of oligosaceharides was not attacked, but the other bonds were hydrolyzed by endo-type action. At the maximum hydrolysis (more than 90~) of birch wood xylan, this xylanase produced X2 to 74-78°~ of the hydrolysates. * Corresponding author.
336
Abstracts of the Articles Printed in Hakkokogaku Kaishi V o l . 70, N o . 2 (1992)
Effect of Ethanol Gas on the Growth of Microorganisms. MASARUYAMASHITA,*TATSUYA ITO, and I-Imosm MtrRASE (Depart-
ment of Agricultural Chemistry, Faculty of Agriculture, Meijo University, 1-501, Shiogamaguchi, Tenpaku-ku, Nagoya 468) Hakkokogaku 70: 101-107. 1992. The effect of ethanol gas on the growth of microorganisms was tested in a small glass vessel. With ethanol gas alone growth inhibition of the microorganisms could not be observed, but with ethanol gas and glycerol growth of the microorganisms was inhibited. After the ethanol gas test, about 80°~ of the ethanol was absorbed in the agar medium and the ethanol in the vessel air was about 1/200-1/1000 of that in the medium. From inhibition tests with different volumes of agar medium, we concluded that growth inhibition of microorganisms with ethanol gas was mainly due to the ethanol absorbed in the medium and not to that in the vessel air. Ethanol absorption into the agar medium was found to be a fairly lengthy process, and the ethanol content in the medium came to equilibrium only after 2-3 d. The low ethanol content in the agar medium during the initial 2 d allowed cells to grow when ethanol gas alone was added. Glycerol added with ethanol gas seemed to contribute to the inhibition of microbial growth during the initial period. The addition of glucose, Polypepton and starch to the agar medium accelerated the transfer of ethanol into the medium at high ethanol concentrations. These results indicate that studies on the relationship between food components and ethanol absorption into the food are important in terms of food preservation with ethanol gas. * Corresponding author. Purification of Xylanase from Chaetomium gracile Mutant 1161 and Its Xylobiose-Forming Properties. - - N o t e - Tosmo Is.m,'* TETSUYA KONISHI,I TOSmAK~ KUTSUNA,1 KUNIMASA KOGA,2 and TosHrrux.x NAKADA3 (Shin-Nihon Chemical Co. Ltd.,
Showa-cho, Anjyo-shi, Aichi 446, ~Suntory Ltd., Kioi-cho, Chiyodaku, Tokyo 102,2 and Hitachi Zosen Corporation, Sakurajima, Konohana-ku, Osaka 554a) Hakkokogaku 70: 109-114. 1992.
Genetic Organization of the Enzymes Responsible for Degradation of Nylon Oligomers. --Monograph-SEre NEOORO(Department of Biotechnology, Faculty of Engineering, Osaka University, Yamada-oka, Suita-shi, Osaka 565) Hakkokogaku 70: 115-131. 1992. (i) 6-Aminohexanoate-cyclic-dimer hydrolase (EI), exotype 6aminohexanoate-oligomer hydrolase (Eli), and endotype 6-aminohexanoate-oligomer hydrolase (EIII) were found to be responsible for Flavobacterium sp. KI72 degrading 6-aminohexanoate-oligomers, byproducts of nylon-6 manufacture. (ii) The genes for the EI (F-nylA), EII (F-nylB), and EIII (nylC) were encoded on pOAD2, one of the three plasmids harbored in Flavobacterium sp. K172. This plasmid contains two repeated sequences, RS-I and RS-II; one of the two RSiI regions, RS-IIA, contains the F-nylB gene, while the other, RS-IIB, contains the homologous EII' gene (nylB). The F-nylB and nylB" have 88% similarity in their nucleotide sequences, an open reading frame encoding a polypeptide of 392 amino acids. Catalytic activity of the EII' protein toward 6-aminohexanoate-dimer was approximately 0.5% of that of the EII enzyme. (iii) Construction of various hybrid genes obtained by exchanging fragments flanked by conserved restriction sites of the F-nylB and nylB' genes demonstrated that two amino acid replacements in the EI I' enzyme, i.e. Gly 181-+Asp (EII type) and His266--+Asn (EII type), enhanced the activity toward 6-aminohexanoate-dimer 200 fold. (iv) The EI and EII enzymes were found in another 6-aminohexanoate-cyclic dimer degrading bacterium, Pseudomonas sp. NK87. The El gene (P-nylA) and EII gene (P-nylB) of NK87 strain were located on the 23-kilo-base pairs (kbp) and 80kbp plasmids, respectively. The F-nylA and P-nylA genes encoded polypeptide of 493 amino acids and had l0 base substitutions in the coding region. In contrast to the high homology of the nylA genes, the F-nylB and P-nyIB genes had only 55°~ similarity in the nucleotide sequences, and 35~ similarity in the deduced amino acid sequences. On the basis of the structure of nylA, nylB and nylC genes, we discussed how nylon oligomer degradation genes were evolved. Discussion of the Origin of Ancient Japanese Sake: Sake Brewing by Means of Chewing and Sprouting. --Miscellany-SEn~osur~ UEDA (Department of Applied Microbiology, Kumamoto Institute of Technology, Ikeda 4-22-1, Kumamoto 860) Hakkokogaku 70: 133-137. 1992. From a study of various records, the author suggests that Japanese sake may have originated as follows. The Jyomon people --the first inhabitants of Japan-- were taught sake brewing by means of chewing rice by the non-Chinese people who crossed the East China Sea to Japan from the southern part of China in the 5th century BC. Later, the Yayoi people --Chinese people who came from China or Korea to Japan-- taught the Japanese people sake brewing by means of sprouted rice in the 2nd-4th century AD. From the 4th to the 9th centuries AD, the sprouted rice saccharifying agent was improved through adding sprouted rice infected by Aspergillus oryzae to steamed rice infected by A. oryzae, that is koji.
A xylanase (CG) from a solid-state wheat-bran culture of
Chaetomium gracile Mutant 1161 was purified by ethanol fractionation and CM-Sepharose CL-6B column chromatography. The purified CG was found to be homogenous on PAGE. The molecular weight was estimated to be 11,000 by Sephadex G-75 gel filtration, 19,000 by SDS-PAGE. 8 M Urca-SDS-PAGE showed that this enzyme consisted of two subunits of 14,400 and 4,800. The isoelectric point was 8.35. The enzyme was inactivated by NBS, SDS, PCMB, and HgC12. The maximum xylobiose (X2)-forming activity (ability) was shown at pH 5.0 and 50°C; pH and thermal stability ranges were at pHs 4.0--7.0 and up to 45°C. The purified CG could not hydrolyze X2. From an analysis of the bond cleavage of xylooligosaccharidealditols, it was found that the first bond from the non-reducing end of oligosaceharides was not attacked, but the other bonds were hydrolyzed by endo-type action. At the maximum hydrolysis (more than 90~) of birch wood xylan, this xylanase produced X2 to 74-78°~ of the hydrolysates. * Corresponding author.
336