著者
今中 忠行
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.80, no.1, pp.2-9, 2002-01-25
参考文献数
15

There are a huge number of microorganisms in the extreme environment. For example, we can isolate many extremophiles such as hyperthermophiles, psychrophiles, and so on. The phylogenetic tree based on 16S rRNA or protein sequences shows that all organisms have a common ancestor. All organisms are divided into three groups, eucarya, bacteria, and archaea. Thermococcus kodakaraensis KOD1 is a newly isolated hyperthermophilic archaeon from a hot spring at a wharf of Kodakara Island, Kagoshima, Japan. The optimum temperature for KOD1 cell growth is 95℃. The KOD1 strain possesses a circular genome, whose sequence has been determined (approximately 2076 kb). Most enzymes from KOD1 are extremely thermostable and the reason for thermostability was analyzed by determining the tertiary structure of those enzymes. A rapid and efficient method of amplifying specific DNA sequences by KOD1 DNA polymerase and characteristics of glutamate dehydrogenase, DNA ligase, and Rubisco are introduced here.
著者
今中,忠行
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.80, no.1, 2002-01-25

There are a huge number of microorganisms in the extreme environment. For example, we can isolate many extremophiles such as hyperthermophiles, psychrophiles, and so on. The phylogenetic tree based on 16S rRNA or protein sequences shows that all organisms have a common ancestor. All organisms are divided into three groups, eucarya, bacteria, and archaea. Thermococcus kodakaraensis KOD1 is a newly isolated hyperthermophilic archaeon from a hot spring at a wharf of Kodakara Island, Kagoshima, Japan. The optimum temperature for KOD1 cell growth is 95℃. The KOD1 strain possesses a circular genome, whose sequence has been determined (approximately 2076 kb). Most enzymes from KOD1 are extremely thermostable and the reason for thermostability was analyzed by determining the tertiary structure of those enzymes. A rapid and efficient method of amplifying specific DNA sequences by KOD1 DNA polymerase and characteristics of glutamate dehydrogenase, DNA ligase, and Rubisco are introduced here.
著者
関口 順一
出版者
日本生物工学会
雑誌
醗酵工学会誌 (ISSN:03856151)
巻号頁・発行日
vol.61, no.3, pp.p129-137, 1983-05

Patulin is a typical mycotoxin originally isolated from Penicillium patulum as an antibiotic, and the patulin biosynthetic pathway is a classical example of the large group of polyacetate-dervied secondary metabolites known as polyketides. Unexpected metabolites produced by a patulin-deficient mutant revealed a new portion of the pathway. We have investigated the patulin biosynthetic pathway with the aid of several patulin-deficient mutants, pathway enzymology, bioconvesion of metabolites, and immobilized cell techniques. It was found that three mycotoxins (phyllostine, isoepoxydon and ascladiol) and a new lactone (neopatulin) exist on the pathway. Two dehydrogenases among the pathyway enzymes were characterized. Furthemore, in contrast to the accepted assumption, monooxygenase mediated the ring cleavage of an aromatic precursor, gentisaldehyde. Finally, the patulin pathway becomes twice as long as the portion known before 1978,and is one of the best characterized pathways of secondary metabolism. In this monograph, mechanisms of the conversion of phyllostine to neopatulin, and neopatulin to phyllostine, are proposed, and a pathway for the related mycotoxin, penicillic acid, is also discussed.
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

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.