الفهرس 
Sources of microorganismsOnly 14 pages are availabe for public view
 |  | from | 175 |  |  |
| | | from | 175 | | |
Abstract
a t r i a l t o study the d i s t r i b u t i o n of Azotobacter spp. i n various s o i l s of Kafr El-Sheikh Governorate as well as i n the d i f f e r e n t root regions of tomato plant. Azotobacter and s a l i n e s o i l s . Cultivated habitae f o r these organisms. was absent from sandy s o i l s were the best The type of cultivated crop and the location of s o i l affected the density of d i s t r i b u t i o n of t h e s e b a c t e r i a . Azotobacter spp. appeared t o prefer the rhizoplane of tomato roots than the rhizosphere o r t h e f r e e s o i l . from Kafr El-Sheikh Governorate 18 d i f f e r e n t s t r a i n s of Azotobacter spp. were i s o l a t e d , p u r i f i e d , i d e n t i f i e d and t e s t e d f o r t h e i r various biological a c t i v i t i e s . Organism number 3 , which was i d e n t i f i e d a s -Az. chroococcum w a s t h e most active one i n growth, nitrogen-binding capacity, production of water-soluble vitamins ( r i b o f l a v i n and ascorbic acid) and biosynthesis of plant growth regulating substances