2006 Fiscal Year Final Research Report Summary
Research for the symbiotic system in a bioreactor where anaerobic ammonium oxidation proceeds.
| Project/Area Number |
16560687
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biofunction/Bioprocess
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| Research Institution | Sojo University |
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Principal Investigator |
FUJII Takao Sojo Univeresity, Biotechnology and Life Science, Professor, 生物生命学部, 教授 (80165331)
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| Co-Investigator(Kenkyū-buntansha) |
FURUKAWA Kenji Kumamoto University Graduate School, Science and Technology, Professor, 大学院自然科学研究科, 教授 (60029296)
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| Project Period (FY) |
2004 – 2006
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| Keywords | anaerobic ammonium oxidation / Anammox / denitrification / nitrite reductase / nir S |
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| Research Abstract |
Hydrazine-oxidizing enzyme (HZO) of an Anammox bacterium was characterized and the nucleotide sequence encoded by the HZO gene was determined. The enzyme has oxidizing activity towards hydrazine but not hydroxylamine. With cytochrome c as an electron acceptor, the Vmax and Km for hydrazine are 6.2±0.3 μmol/min・mg and 5.5±0.6 μM, respectively. Hydroxylamine work as a competitive inhibitor (Ki:2.5 μM) for hydrazine oxidation by HZO. The HZO appeared to be more than 10% of the total protein weight in the cells of the KSU-1 strain. It is likely that HZO play crucial roles in the catabolism of the anammox bacterium. Two genes, hzoA and hzoB encoded HZO. The expression of hzoB was 3 to 5 fold as much as that of hzoA.
Meta-genomic DNA was extracted from the sludge whose population was largely composed of an Anammox strain KSU-1, and analyzed. Besides the genes of strain KSU-1, the gene homologous to those of bacteria such as Geobacter, Roseiflexus, Anaeromyxobacter, Burkholderia, Kineococus. Azarcus, Syntrophus, Solibacter, Chloroflexus, Mthanosarcina, Blastopirellula, Leishmania, and Rhodopirellula were found. In the other hand, nitrite reductase genes (nir S) were amplified with nir S-specific primers and the DNA by PCR. However, the expression level of nir S was significantly low.
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