간척지토양(干拓地土壤)의 수도근권(水稻根圈)에서 협생질소고정(協生窒素固定)에 관(關)한 연구(硏究) -제(第)1보(報) 수도(水稻) 및 자연생잡초(自然生雜草) 근조직내(根組織內) 협생질소고정균(協生窒素固定菌)의 분리동정(分離同定)

Associated Nitrogen Fixation in the Rhizosphere of Rice in Saline and Reclaimed Saline Paddy Soil -1. Enumeration of aerobic heterotrophic bacteria associated in histosphere of grasses and rice

The aerobic heterotrophic bacteria in the histosphere associated with grasses (Gramineae, Caryphyllaceae, Crucifereae) and rice cultivars in saline and reclaimed saline paddy soils were varied with species and rice cultivars. The fraction of aerobic heterotrophic $N_2$-fixing bacteria to the total aerobic heterotrophic bacteria were averaged to eighteen percent in the histosphere of grasses and rice. Acetylene reducing activity of these bacteria were ranged from 1 to 24 n mole/tube/hr. Most of the bacteria strains were predominated of hydrogen utilizing bacteria. The majority of these bacteria were closed to Pseudomonas, Azospirillum, Klebsiella and Agrobacter.