Diversity and population of ammonia oxidizing bacteria in soil.

2003 Fiscal Year Final Research Report Summary

• Project/Area Number: 14560050
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Plant nutrition/Soil science
• Research Institution: Shizuoka University
• Principal Investigator: HAYATSU Masahito Shizuoka University, Faculty of Agriculture, Professor, 農学部, 教授 (70283348)
• Project Period (FY): 2002 – 2003
• Keywords: nitrifying bacteria / ammonia oxidizing bacteria / real-time PCR / diversity

Research Abstract

Autotrophic nitrifying bacteria, ammonia oxidizing bacteria and nitrite oxidizing bacteria, play an important role in the nitrogen cycle in soil ecosystem. Recent studies indicated that there are some genera and many species of ammonia oxidizing bacteria in a soil. However population of individual species have not been determined. In the present study we analyzed diversity of ammonia oxidizing bacteria in the tea field soil by PCR-DGGE, and characterized the ammonia oxidizing bacteria isolated from the soil. Population of the ammonia oxidizing bacteria isolated was estimated by real-time PCR.
1)The 16SrDNA bands of Nitrosomonas, Nitrosospira and Nitrosococcus genus were detected by DGGE analysis. The DGGE band pattern obtained from amplified 16SrDNA showed existence of Nitrosococcus sp. belonging to γ-proteobacteria.
2)Three genera and five species of ammonia oxidizing bacteria, Nitrosomonas sp.TNE100, Nitrosospira sp.TNL100, TNL200, TNL300, and Nitrosococcus sp.TAO100, were isolated and characterized. The taxonomic properties such as growth rate, GC-content, and morphology of the isolated ammonia oxidizing bacteria were investigated.
3)The bacterial numbers were determined by real time PCR using Taq-Man probe designed for 16SrDNA of each ammonia oxidizing bacterium. This method was able to count the bacterial number in the range of 10^3 to 10^6.