عزل و اختبار كفاءة كل من بكتيريا Azotobacter وبكتيريا Burkholderia المعزولتين محليا من الترب الليبية في تثبيت النتروجين الجوي

Abstract EN

An experiment was conducted in the Soil Microbiology Laboratory of the Faculty of Agriculture, University of Tripoli, testing the efficiency of locally isolated Azotobacter and Burkholderia in fixing atmospheric nitrogen.

The experiment included isolation and diagnosis of Azotobacter and Burkholderia from near-root soils of various plants brought from different regions of the city of Tripoli and its surrounding suburbs.

Ten isolates were obtained as a result of making dilutions of these soils.

The biochemical, morphological, and microscopic traits of them were studied.

The results showed that all isolates belong to the two types of Azotobacter and Burkholderia and that the numbers of Azotobacter bacteria are abundant in the root zone (Rhizosphere) of some plants used in the research, whose numbers ranged between (1.95 x 10³ 6.1 x 10¹0) cfu / gm soil.

Also, the amount of nitrogen fixation by Azotobacter bacteria ranged between (6.8-18.50) mg/l, while Burkholderia bacteria numbers ranged between (9.4 × 108-1.5 x 10³) cfu/gm soil and the amount of nitrogen fixation ranged between (5.38-15.50) mg/l.

There were also significant differences between Azbacter and Burkholderia bacteria in terms of their numbers and ability to fix atmospheric nitrogen.

However, both genera can be used in biological fertilization programs in Libyan soil.