Abstracts of the Articles Printed in Hakkokogaku Kaishi

V o l . 6 8 , N o . 1 ( 1 9 9 0 )

S~electivity between and Ethanol as Glucosyl-Accepter.* KIYOSHI MAEKAWA,* MORIMASA INOUE, SUGURU SUMITA, MITUO YASUI, and TAmA FUI1MURA (Industrial Research Institute of Hyogo Prefecture, 3-1-12 Yukihira-cho, Suma-ku, Kobe 654) Hakko- kogaku 68: 1-7. 1990.

The fl-glucosidase from Trichoderma viride (Meicelase P- l ) has glucosyltransferase activity. In this study, the effects of the alcohol concentrat ion on the ethyl-fl-glucoside format ion by the fl- glucosidase were investigated to study the selectivity between water and ethanol as the glucosyl-accepter. Cellobiose was used as the glucosyl-donor. There were two different main reactions. One is reac- tion 1 in which ethyl-fl-glucoside (1 tool) and glucose (1 mol) are formed f rom cellobiose (1 tool) and ethanol (1 mol), the other is reaction 2 in which 2 mol of glucose are formed from cellobiose (1 tool). The results obtained were as follows. With the increase of alcohol concentrat ion, ethyl-fl-glucoside was increased. When the substrate existed, the ratio o f progression of reaction 1 to reaction 2 was constant at alcohol concentrat ions f rom 10 to 60%. The selective ratio of reaction 1 was about 50 times that o f reaction 2. The activity o f the fl-glucosidase is lower at higher alcohol concentrat ions (50 or 60°/oo). After the substrate was consumed, the hydrolysis of ethyl-fl- glucoside became predominant . At lower alcohol concentrat ions, oligosaccharides such as cellotriose were temporarily formed but disappeared as with the reaction proceeded. From the above facts, we concluded that in the glucosyltransfer reaction by fl-glucosidase, the preference for ethanol over water as the glucosyl-accepter was about 50 times higher and independent of the ethanol concentrat ion.

* Corresponding author. * Formation of Ethyl-fl-Glucoside from Cellobiose by fl-Glucosidase (I).

Isolation and Identification of Lignin-Modifying Microorganism. MOTOO ARM,* KATUHIKO WAKINO, + and SAWAO MURAO~ (Depart- ment of Agricultural Chemistry, College of Agriculture, University of Osaka Prefecture, Sakai, Osaka 591) Hakkokogaku 68: 9-15. 1990.

Alkali lignin f rom rice straw was prepared by extraction with hot alkali (1% NaOH, 100°C, 3 h). Polysaccharides in alkali lignin were digested by the cellulase f rom Aspergillus aculeatus. During screening o f microoganisms that dgrade alkali lignin of rice straw, a lignin- modifying microorganism was isolated f rom soil. The extent of lignin modification was estimated by solubilizing lignin in dioxane: 0.1 N HC1 = 9 : 1. The strain was identified as Pseudomonas caryophylli by its taxonomical characteristics. The strain seemed to modify 1.2% of lignin almost completely in only 24h of cultivation at 30°C in a medium containing meat extract and yeast extract. The bacterium seems to modi fy alkali lignin a l though complete decomposi t ion or monomer iza t ion of alkali lignin was not obseved in the cultivation with this bacterium. The bacterium decomposed the high molecular weight fraction of alkali lignin. Demethoxylat ion in lignin was also observed.

* Corresponding author. + Present address: Sankyo Co. Ltd. ± Present Address: Department of Applied Microbial Technology, The

Kumamoto Institute of Technology.

Production of Lactic, Acetic, Propionic, and Butyric Acid by Bulking Activated Sludge. RIKIYA TAKAHASHI,* KOHJI KOYAMA, KAZUAKI YASUMURA, SHOUICHI KAWAKITA, MASAHARU SUZUKI, and HITOSHI YONEYAMA (Depart-

ment of Brewing and Fermentation, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156) Hakkokogaku 68: 17- 23. 1990.

The previous findings that activated sludge bulking was st imulated by 80 mg/l of lactic acid, acetic acid, and glucose, and that the lactic acid consumpt ion rate increased in the bulking activated sludge, led to an idea that added glucose would be immediately con- verted to these organic acids in the aeration tank. As the result, therefore, no organic acid was detected upon the addition of 80 mg/I of glucose, but the activated sludge was bulked severely. When 160 mg/l of glucose was provided to the sludge continuously, a small amoun t of lactic acid was detected in the aeration tank. Acetic, pro- pionic, butyric, and lactic acid were accumulated and the sludge bulk- ing occurred after artificial wastewater was given which contained 500 mg/l of glucose. The activated sludge bacteria produced lactic acid without a lag when they were incubated with 80 mg/I of glucose under limiting oxygen.

* Corresponding author.

Simulation Study of the Fermentation-Process of Sake-Mash Using Powdered a-Rice, t - - N o t e - - KAzuo SATO, I* HITOSHI UTSUNOMIYA, 2 KYOICHI KONDO, 3 HIDEO MISHIMA, 3 SHIGEZO TAKEMURA, 3, and KIYOSHI YOSHIZAWA ~§ (National Research Institute of Brewing, 2-6 Takinogawa, Kita-ku, Tokyo 114, Tax Administration Bureau of Takamatsu, 2-10 Tenjinmae Takama- tsu 760, 2 and Hakutsuru Sake-Brewing Co. Ltd., 4-5-5 Sumiyoshi- Minami-cho, Higashi-Nada-ku, Kobe 6583) Hakkokogaku 68: 25- 29. 1990.

The fermentation-process of sake-mash using powdered a-rice was simulated, according to a material-dissolution and ethanol- product ion model. The powdered a-rice had about 7 times as high an initial dissolution rate as ordinary material. The simulated result showed a stable condit ion of dissolution of the materials, and the fea- sibility of this method for the process-control o f sake-mash.

* Corresponding author. § Present address: Tokyo University of Agriculture. * Measuring and Controlling in Sake-Making Process (V).

Ammonium Oxidation by an Activated Sludge Process with Cross- Flow Filtration. - - N o t e - - TASHIRO,* YUICHI SUWA, and TAKAO YAMAGISHI (Water Pollution Control Department, National Research Institute for Pollution and Resources, Ministry of International Trade and Industry, Onogawa 16-3, Tsukuba, Ibaraki 305) Hakkokogaku 68: 31-34. 1990.

Oxidation o f inorganic a m m o n i u m (NH4 ÷) was done by an ac- tivated sludge process with cross-flow filtration. The reactor was operated by a complete mixing and cont inuous feeding method. Ac- tivated sludge was seldom drawn off to retain slow growing nitrifiers in the reactor well. Al though no organic substances were supplied to the reactor, the sludge concentrat ion increased up to 6,600- 8,700 mgVSS/I. No a m m o n i u m nitrogen was detected in the effluent, with the reactor was operated with a m m o n i u m loading up to 0 .79- 1.18 g NH4-N. l - J. d t. The a m m o n i u m oxidation rate reached 1.90 g NH4_N.I-J .d 1; this value is six-fold higher than the max imum nitrification rate when Kjeldahl nitrogen and organic substance were treated by this activated sludge process at the same time.

* Corresponding author.

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