ISOLATION AND IDENTIFICATION OF RHIZOBACTERIA FROM MAIZE (ZEA MAYS L.) IN LUVISOLS AND DOCUMENTATION THEIR PLANT GROWTH PROMOTING TRAITS

There is a growing interest in the issue of inoculation of rhizobacteria into the agricultural soil because this group of bacteria can increase productivity and quality of agriculturally important crops and contributes to the stability of agroecosystems. The aim of our work was to isolate and characterize of plant growth promoting traits (production of IAA, siderophores, phosphate solubilisation, antifungal activity) of rhizobacteria belonging to a group of plant growth promoting rhizobacteria (PGPR), from rhizosphere of maize (Zea mays L.) in luvisols. Quantitative representation of rhizobacteria of maize rhizosphere was 7.4 . 10(6) CFU.g(-1) dry soil. A total of eleven species of maize rhizosphere where isolated and confirmed as PGPR in vitro. The all isolates showed positive indole-3-acetic acid (IAA) production ranging between 1.39 and 15.74 mu g.ml(-1). Seven strains (63.6 %) has been shown with low and 1 strain with intermediate solubilisation index of phosphates and the positive production of siderophores showed 7 isolates (63, 6 %). Except for the isolate KmiJP17B089, all others inhibited the growth of Sclerotinia sclerotiorum and Rhizoctonia solani by more than 50 %. In the case of Fusarium graminearum, on the other hand, we observed a very low inhibitory activity. Three isolates which were the most active in observed traits were identified by the 16S rRNA gene sequencing and by BLAST alignment of NCBI database as Bacillus altitudinis strain KmiJP17B089, Bacillus aryabhattai strain KmiJP17B090 and Bacillus megaterium strain KmiJP17B091. These results suggest the possibility of in vitro testing of these Bacillus species as potential biological fertilizer to increase maize production.