Characterization of Azospirillum spp. Isolated from Korean Paddy Roots

우리나라 수도근권에서 분리된 Azospirillum spp.의 특성

Nitrogen fixing activity associated with 40 varieties of rice was assayed at heading stage by an in situ acetylene reduction method. The in situ acetylene reduction activity and population of nitrogen fixing bacteria obtained on nitrogen-free malate medium for Azospirillum spp. enrichment showed positive correlation. Six Azospirillum spp. with high nitrogenase activity were isolated from the rice roots, from which five spp. were identified as A. lipoferum and one was A. brasilense. The physiological characteristics of the six Azospirillum isolates, that is, carbon source utilization, biotin requirement, antibiotic resistance, indole acetic acid excretion, plasmid profile and protein patterns were compared.

영남작물시험장에서 질소비료 공급없이 재배합 40종의 수도품종으로부터 출수기전의 수도근권의 질소고정력을 in situacetylene 환원력 측정방법으로 시험한 결과 Azospirillum 균의 무질소 malate 배지에서 얻은 균주와 상관관계를 보였다. 이 중 질소고정력이 높은 6종의 Azospirillum을 분리 동정한 결고 5종은 A. lipoferum, 1종은 A. brasilense임을 확인한 후 이들 6종의 Azospirillum들의 당이용성, biotin 요구성, 항생제저항성, auxin 생산성, plasmid profile 및 균체단백질 pattern을 비교 분석하였다.