Isolation and Identification of Nitrogen-fixing Bacilli
DING Yan-Qin1 WANG Jian-Ping1 LIU Yuan1 Chen San-Feng1** WANG You-Shan2 XING Li-Jun2
(1. State Key Laboratory for Agrobiotechnology, College of Biology, China Agricultural University, Beijing 100094, China; 2. Institute of Plant Nutrient and Natural Resource, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100089, China)
Abstract Abstract: A total of 29 isolates were selectively obtained from the rhizospheres of wheat(Triticum aestivum ), maize(Zea mays ), ryegrass(Lolium sp. ) and willow(Salix sp.) based on their growth on nitrogen-free medium and their resistance to 100 ℃ for 10 min. 7 out of them had nifH gene determined by PCR amplification and belonged to the genera Bacillus and Paenibacillus based on their physiological and chemical characteristics, 16S rDNA sequence (GenBank accession No. AY373358, AY373360~AY373364 and AY376876), G+C mol% and DNA-DNA hybridization. And the isolate T1 was identified as Bacillus cereus. The isolates G1, C4 and C5 were identified as Bacillus megaterium. The isolates W5 and G2 were simlar to Bacillus marisflavi and Paenibacillus polymyxa in physiological and chemical characteristics, 16S rDNA and G+C mol%, respectively. The isolate T7 might represent a novel species of Paenibacillus.
