Journal of Pure and Applied MicrobiologyVol. 9 No. Special Edition May. 2015

Newly Isolated Rhizobacteria as Plant Growth Promoters For Maize Plant (Zea mays) under Water Stress

E.E. El-Sharouny* and A. F. Moustafa

Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt.

Received on 08 January 2015 and accepted on 24 March 2015



Plant growth promoting rhizobacteria (PGPR) offers an attractive way to replace chemical fertilizers, pesticides, and supplements. In the current study, nine rhizobacterial strains isolated from the rhizoshere of clover (Trifolium) and wheat (Triticum) plants were tested for multiple plant growth promoting activities (NH3, IAA production, catalase and oxidase activity). Later, they were genetically idendified by 16S RNA sequence analyses as Bacillus subtilis, Bacillus cereus, Pseudomonas mendocina, Pseudomonas putida, Kocuria marina, and Kocuria rhizophila. The rhizobacterial strains were then applied individually, for the evaluation of maize seedling growth promotion activity. Finally, the interaction between the rhizobacterial strains in addition to a previously identified rhizobacterium Bacillus licheniformis, was investigated by applying the Plackett-Burman experimental design under different levels of water stress. The percentages of germination, carbohydrate, and protein production were measured as physiological responses indicating the effect of the bacteria on plant health.

Keywords : Plant growth promoting rhizobacteria, maize plant, Plackett-Burman, water stress.