著者

三沢,典彦

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.93, no.7, 2015-07-25

著者

田中,享

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.93, no.1, 2015-01-25

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光合成細菌変異株R. sphaeroides CR-720株は,前駆体として50mMグルコース,60mMグリシン,ALA脱水酵素阻害剤として5mMレブリン酸および5g/L酵母エキス存在下,3L発酵槽でALAを生産させたところ,ALA生産に伴って増加する未知のアミノ酸を検出した.未知のアミノ酸は5-アミノ-4-ヒドロキシ吉草酸(AHVA)と同定した.CR-720株は培養温度32℃条件下でALAを41mM生産したときAHVAを2.9mM生産した.光学異性体分離カラムを用いた高速液体クロマトグラフィーにより,CR-720株は(S)-(+)-AHVAを特異的に生産していることを確認した.培養温度を検討した結果,28℃でALAを44mM生産したとき,AHVA生産量は1.1mMであった.さらにALA生産の培地を改良し,5kL発酵槽を用いて培養温度28℃および通気速度0.02vvm一定条件下で攪拌速度を調節し溶存酸素濃度を0.5mg/L以下に制御した結果,最終的にCR-720株によるAHVAの生成を1.9mMに抑制でき,ALAが72mM生産され,生産速度として1.4から1.5mM/hを得た.

著者

山本(前田),万理

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.86, no.2, 2008-02-25

著者

三浦,郁夫

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.86, no.1, 2008-01-25

著者

柴田,富士子

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.93, no.2, 2015-02-25

著者

本波 康由

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi (ISSN:09193758)

巻号頁・発行日

vol.90, no.11, 2012-11-25

参考文献数

6

著者

釜澤 尚美

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.91, no.10, 2013

著者

池,晶子

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.90, no.11, 2012-11-25

著者

池,晶子

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.89, no.6, 2011-06-25

著者

池,晶子

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.89, no.5, 2011-05-25

著者

重松,亨

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.87, no.12, 2009-12-25

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Methane fermentation, consisting of anaerobic degradation of organic matters and subsequent methanogenesis, is one of potentially attractive technologies for treatment of wastewater and biological wastes. Because methane fermentation is a cost-effective energy-yielding process, produces far less excess sludge than aerobic wastewater treatment systems, and a large part of the energy stored within organic matters can be recovered as biogas. However, it also has disadvantages, such as poor treating rate, low digestion efficiency and instability in reactor operation. These disadvantages are caused by the difficulty of monitoring in situ microbial community structure and metabolic functions in bioreactors. Methane fermentation is based on a complex community of microorganisms of wide phylogenetic diversities with different metabolic functions. Moreover, only poor proportion of microorganisms have been isolated and cultivated and analyzed. One possible approach to solve these disadvantages and achieve high rate and high efficient methane fermentation processes with stable reactor operation is, thus, to accumulate knowledge of the microbial communities and to use them as landmarks responsible for specific degradation pathways in methane fermentation. Therefore, we constructed continuous anaerobic methane fermentation processes using completely stirred tank reactors (CSTR) fed by specific substrates, such as acetate, propionate, butyrate, long-chain fatty acids, glycerol, protein (bovine serum albumin) and starch, to achieve the chemostat cultivations of microbial communities related to degradation of these substrates. For each microbial community under steady state conditions, we analyzed the structures and metabolic functions by mainly using molecular biological techniques, such as fluorescent in situ hybridization, 16S rRNA gene clone library analyses, quantitative real-time PCR techniques, quantitative RT-PCR and denaturing gradient gel electrophoresis. Even feeding the same substrates, the microbial communities were remarkably different by different dilution rates. For acetate-degrading communities, dilution rate effected the change in community structure, as well as shift of pathway between aceticlastic and non-aceticlastic methanogenesis. Additional Ni^<2+> and Co^<2+> in the wastewater fed into the reactors and operation temperature also affected on the community structure, as well as the reactor performance. Based on the fundamental knowledge in the landmarks of microbial communities for specific degradation pathways of organic matters, we subsequently evaluated the relationship between reactor performance and microbial community structures in bioreactors treating actual wastewaters and biological wastes, such as municipal solid wastes, awamori distillery wastewater, livestock manure and surplus sludge of a wastewater treating plant. Our research results would provide a significant milestone for achievement of stable operational methane fermentation process with high rate and efficiency.

著者

辻,巌

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.89, no.2, 2011-02-25

著者

河合 美佐子

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi (ISSN:09193758)

巻号頁・発行日

vol.89, no.11, pp.679-682, 2011-11-25

参考文献数

14

著者

米田,宏

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.92, no.2, 2014-02-25

著者

古本 強 坪田 博美 植木 龍也 三浦 郁夫

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi (ISSN:09193758)

巻号頁・発行日

vol.87, no.7, pp.343-347, 2009-07-25

著者

竹村,浩

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.82, no.3, 2004-03-25

著者

菅-岸本,三佳

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi

巻号頁・発行日

vol.92, no.9, 2014-09-25

著者

滝口 昇

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi (ISSN:09193758)

巻号頁・発行日

vol.89, no.12, pp.732-738, 2011-12-25

参考文献数

42

著者

山下 道雄 松田 充功 大畑 暢敬 神田 宗和 檜垣 知臣

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi (ISSN:09193758)

巻号頁・発行日

vol.83, no.3, pp.123-131, 2005-03-25

参考文献数

3

被引用文献数

1

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In 1989, in the course of our screening for new antifungal antibiotics with cell wall synthesis inhibition activity, FR901379 (WF11899A) was discovered in the culture broth of Coleophoma empetri F-11899. The strain was isolated from a soil sample collected in Iwaki city, Fukushima-prefecture, Japan. Because FR901379 had hemolytic activity, we decided to screen for semi-synthesis derivatives with low toxicity and high antifungal activity and evaluated many derivatives with substituted side chains. We started by using Actinoplanes utahensis to replace the palmitoyl group of FR901379 with other organic acids. After synthesizing several hundred organic acids and making repeated derivatives, we discovered FR131535, which had similar antifungal activity to FR901379 in vitro and in vivo and low hemolytic activity. It was not however selected as a development candidate because of insufficient antifungal activity. In the search for a more potent compound, we hypothesized that a compound with a similar molecular structure to FR131535 might produce a good antifungal drug. We therefore began the screening of Fujisawa's original acylase using a specially devised and effective screening system. After discovering "FR901379 Acylase" produced by Streptomyces sp. No. 6907, we continued with our evaluation of derivatives. We finally selected FK463 as a candidate compound for commercial drug development. In 1990, to establish an industrial manufacturing method for Micafungin (FK463), our laboratories (Fermentation Development Laboratories) commenced the following development research : (1) strain improvement of Coleophoma, (2) screening of "FR901379 Acylase"-producing strains, (3) studies to increase the scale of fermentation of FR901379 and "FR901379 Acylase", (4) determination of effective purification procedures for FR901379, a key intermediate of FR179642 and FK463, and (5) development of a HPLC assay system to measure the amount of objective compounds and impurities. Micafungin (general name, Trade mark : Funguard, Development No. : FK463) was launched in Japan on December 6, 2002. Approval in the USA and EU is pending and expected shortly.

著者

添田 愼介 明石 健志 前田 清 川北 毅

出版者

日本生物工学会

雑誌

生物工学会誌 : seibutsu-kogaku kaishi (ISSN:09193758)

巻号頁・発行日

vol.76, no.9, pp.389-397, 1998-09-25

参考文献数

11

被引用文献数

2

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Tacrolimus is an immunosuppressant macrolide isolated from Streptomyces tsukubaensis. It is used clinically to prevent the rejection of tissue transplants. To achieve the industrial production of tacrolimus, development research was aimed at breeding strains that efficiently produce tacrolimus, optimizing the cultivation conditions, determining an effective purification method, and establishing a means of rapid quantitative analysis. The wild-type S. tsukubaensis was sequentially treated with ultra violet light to furnish various types of morphologically altered mutants, from which a desired strain was selected and bred. For the fermentation of the new strain, a cultivation medium was formulated with a low viscosity and resistant to thermo-denaturation on sterilization. In a scale-up study, in which the fermentor size was increased from 30l to 25kl, the productivity of tacrolimus was found to be well reproduced by keeping both the dissolved oxygen and the agitation at low levels during the growth phase of the producing strain. As a result of these procedures, the concentration of tacrolimus in the fermentation broth was increased 300-fold over that obtaind in the early stages of the research with the wild strain. S. tsukubaensis produces many kinds of proteins and oligosacchalides as well as various types of tacrolimus related compounds. To remove these impurities effectively, the cultivation broth was directly extracted with acetone. The extract was successively purified with a high porosity absorbance resin, and acidic and natural silica gel column chromatography, followed by recrystalization in aqueous acetonitrile, to obtain tacrolimus monohydrate. Tacrolimus itself is readily converted to optical and steric isomers in an aqueous solution. When tacrolimus was analyzed by HPLC at lower temperatures, the peaks corresponding to the macrolide were complex because of cis-trans isomerization in the column. The problem was overcome by heating the column to 50℃, when the isomerization rate was so high that the peaks were fused into a single, sharp one. The epimerization ratio was found to depend on the concentration of water in the solution, but the ratio remained constant when a Brij-35 solution used as a diluent. By these procedures, a simple, rapid and reliable analytical method was established. The industrial production of tacrolimus was thus achieved by a combination of fermentation, purification, and analytical investigations.