الفهرس 
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Abstract
The aims of the present study were to (i) isolate some of the most common vermicompost beneficial associated bacteria, (ii) characterize these isolates on the basis of some morphological and physiological attributes as well as by 16S rRNA gene sequence analysis, and (iii) evaluate the antagonistic effects of these isolates against four of the major phytopathogens that attack vegetable crops causing a significant reduction in production. The experiments were also extended to (v) evaluating the potential role of the present isolates on the plant growth promotion of cowpea plants. The data of the conducted experiments could be summarized as follow:
1-A total of ten ten vermicompost’s bacterial strains, differentiating in color, texture, morphology, were successfully isolated and purified for further characterization. These bacterial colonies were symbolized as YFV03, YFV04, YFV05, YFV06, YFV09, YFV011, YFV012, YFV013, YFV014 and YFV015.
2-All cells of the pure bacterial isolates produced fast-growing colonies with smooth surfaces and were aerobic, rod shaped, Gram positive. Regarding motility, all isolates were motile conferring their ability to move and colonize roots.
3-All of the tested isolates showed positive results for catalase production suggesting their ability to neutralize the toxic effects of H2O2.
4-Seven of the bacterial isolates were able to produce gelatinase into nutrient gelatine deep tubes except.
5-All of the tested isolates showed positive results for oxidase activities and similarly were able to display amylase activity which was indicated by the clear zones formation in starch agar media.
6-The actual antibiotic sensitivity/resistance assay of the ten isolates to eight different antibiotics (Nitrofurantoin 300, Streptomycin 10, Colistin 10, Clindamycin 2, Amikacin 30, Ceftriaxone, Azithromycin 15 and Penicillin 10). revealed a greater diversity to antibiotics resistance amongst the vermicompost’s bacterial strains.
7-Regarding to the identification of the bacterial strains using 16S rRNA, partial-length of 16S rRNA gene (” " ~ " ” 1500 bp) was successfully amplified and sequenced from the ten isolates. The sequence data have been deposited to the NCBI GenBank. According to the percentages of 16S rDNA sequence similarity with the Closest NCBI strain(s) stored in Genbank database, the ten bacterial isolates in the present work were found to be related to the same genus (Bacillus) with six different species (B. subtilis, B. atrophaeus, B. hemicentroti, B. velezensis, B. nakamurai and B. amyloliquefaciens) demonstrating the domination of the plant beneficial Bacillus strains in vermicompost.
8-In vitro antagonistic activity of the vermicompost associated bacteria against four phytopathogenic fungi (Fusarium solani, Fusarium spp, Macrophomina phasolenia, and Rhizoctonia solani), examined by dual culture test, revealed a considerable diversity of antagonism. All of the ten bacterial isolates exhibited highly significant antagonistic effects against mycelium growth of the tested phytopathogens by forming inhibition zone. All bacterial isolates strongly inhibited the growth of M. phaseolina by forming inhibition zone ranged from 62.22% to 77.78%. Several isolates were significantly reduced mycelial growth of R. solani which reached 64.44% for some isolates. Generally, all bacterial isolates inhibited the mycelium growth of Fusarium solani and Fusarium spp. The highest inhibition growth percentage of F. solani was 65.74 while the highest antagonistic effect against Fusarium spp. was 60%.
9-Concerning to the potential role of the ten selected isolates in growth promotion of cowpea plants, different growth traits, i.e., plant height; shoot length; root length; fresh weight; dry weight of shoots and roots in addition to leaves number, were measured after 30 days of sowing. Most treatments exhibited a significant promotion in shoot length, leaves number, root fresh weight and shoot dray weigh when compared to the control. Some isolates had significant effect on root length, shoot fresh weight and root dry weight,
10-Regarding germination% and growth indicators of cowpea seedling, data revealed that most of the tested bacterial isolates significantly increased the percentage of germination seedling length and vigor index as well.
11-Inoculation with several vermicompost associated bacterial isolates significantly affected the N, P and K contents of leaves which were considerably higher than untreated control
12-Treatment with vermicompost associated bacterial isolates revealed the concordable effect of many bacterial isolates on the photosynthetic pigments (chlorophyll a, b and carotenoids) in the cowpea leaves as compared to control treatment.
Finally, the present data might confirm the efficient isolation of the plant beneficial bacteria strains from vermicompost which in turn can play a significant role in plant growth promotion directly by producing plant growth regulators or indirectly due to their antagonistic properties against different plant pathogens and other pests, thereby improving plant growth and decreasing the yield loss of various crops.