عزل و تشخيص بكتريا Azotobacter chrococcum الأزوتوباكتر و تقييم كفاءة العزلات المحلية و المستوردة في تثبيت النتروجين الجوي

الملخص EN

An experiment was conducted in microbes laboratory in Agriculture college- Basrah university to test efficiency of local and foreign isolates in nitrogen fixation ,included isolation and diagnosis Azotobacter from rhizosphere different plants were brought from different region of Basrah and Thi-Qar province ,then 12 isolates were obtained ,two isolates from Thi-Qar university and one isolate from Italy .

Isolates were diagnosed by biochemical,microscopical and morphological characteristics.

Results showed that all isolates are belong to Azotobacter chrococcum , existed abundance in rhizosphere different plants used in this sudy and ranged between (310×1.1- 510×3.6) cfu gm-1dry soil , also amount nitrogen fixed by Azotobacter in cultural media are ranged between (6.53- 19.00)mg liter.