The potential of GBTUV5 strain as Plant Growth Promoting Bacteria (PGPB) was determined with a series of tests conducted on the strain. Indole acetic acid (IAA) production, phosphate solubility, nitrogen fixation and caseinase activity tests of the strain were positive, which implied GBTUV5's possible use in plant experiments. Positive caseinase activity of the strain led to tests for determining its biocontrol potential, which was validated with positive fungicidal activity against Fusarium oxysporton f. sp. radicis-lycopersici (Forl). The biostimulation effect of the strain was established for the growth of tomato in the presence of a soil system consisted of peat/venniculite/perlite mixture. Tomato seedlings were inoculated with GBTUV5 for varying time intervals, and the best results were obtained with plants inoculated for 2h. A gradual increase of fresh biomass could be observed for the plants with the highest 45.09%, for the seedlings inoculated for 2h. Biomass increase was mainly on the root structure which was attributed to significant IAA production capacity of the strain. The effect of GBTUV5 on the development of the shoot was validated with the increase in dry shoot weight, despite the ambiguous trend observed for shoot length values. The highest increase was obtained as 68.55% in root length values, and a similar trend was also valid for vigor index values with the highest 35% increase. FT-IR and N, P, K analyses conducted on seedlings revealed significant increases in lipid biosynthesis and P uptake, validating GBTUV5's potential as bio stimulator.