Cultivable heterotrophic N2-fixing bacterial diversity in rice fields in the Yangtze River Plain

Guang Hui Xie, Miao Ying Cai, Guang Can Tao, Yosef Steinberger

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


Heterotrophic N2-fixing bacteria are a potentially important source of N2 fixation in rice fields due to the moist soil conditions. This study was conducted at eight sites along a geographic gradient of the Yangtze River Plain in central China. A nitrogen-free solid malate-sucrose medium was used to isolate heterotrophic N2-fixing bacteria. Numbers of the culturable N2-fixing bacteria expressed as CFU (colony forming units) ranged between 1.41±0.42×106 and 1.24±0.23×108 in the sampled paddy field sites along the plain. Thirty strains with high ARA (acetylene reduction activity) were isolated and purified; ARA of the strains varied from 0.9 to 537.8 nmol C2H4 culture-1 h-1, and amounts of 15N fixed ranged between 0.008 and 0.4866 mg·culture-1·day-1. According to morphological and biochemical characteristics, 14 strains were identified as the genus Bacillus, 2 as Burkholderia, 1 as Agrobacterium, 4 as Pseudomonas, 2 as Derxia, 1 as Alcaligenes, 1 as Aeromonas, 2 as Citrobacter, and 3 strains belonged to the corynebacterform group.

Original languageEnglish
Pages (from-to)29-38
Number of pages10
JournalBiology and Fertility of Soils
Issue number1
StatePublished - 1 Jan 2003


  • Acetylene reduction activity
  • N
  • N-fixing bacteria
  • Paddy field


Dive into the research topics of 'Cultivable heterotrophic N2-fixing bacterial diversity in rice fields in the Yangtze River Plain'. Together they form a unique fingerprint.

Cite this