| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2006: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Ammonia oxidizing bacteria (AOB) are phylogenetically classified into 3 genus, Nitrosomonas, Nitrosococcus and Nitrosospira, based on 16S rRNA gene sequence. In former classification, genus Nitrosospira was classified into Nitrosospira (spiral), Nitrosolobus (lobate) and Nitrosovibrio (slender curved rods) with their cell shape, but it is not clear that the elucidation of genetic aspect in morphological difference. In this research it examined concerning the possibility of new phylogenetic marker and we obtained following results.
1. Pure isolation of new strains: From various environment (plant rhizoplane, acid sulfate soil etc.) many AOB were newly isolated. Especially 4 strains which were isolated from acid sulfate soil of Thailand showed physiological properties such as high urease activity which originated in the habitat with acidic condition.
2. Development of new phylogenetic marker :
(1): With PCR cloning, we decided each gene sequence of gap and pgk of 16 AOB strains and analyzed them. It was seen that there were some conserved regions, which were functionally important, compared with same enzyme from other organisms. Phylogenetically tree constructed with gap and pgk generated separate clusters of morphologically different Nitrosospira, Nitrosolobus and Nitrosovibrio, definitely.
(2): We decided gene sequence of pyk of 17 AOB strains with PCR cloning, and analyzed them. Phylogenetic tree constructed with pyk generated separate clusters of morphologically different Nitrosospira, Nitrosolobus and Nitrosovibrio, definitely. It showed more high resolution compared with the tree based on gap or pgk gene sequence.
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