Abstract
Biofilm and Exopolysaccharides (EPS) from bioinoculants have previously displayed industrial applications but their role as plant probiotics is underexplored. In this study, biofilm forming and exopolysaccharides producing microbe (AB-13) was isolated and molecular characterization was done along with plant growth promoting traits. Biofilm and EPS characterization was done by biophysical techniques like XRD, FTIR and SEM-EDAX which revealed amorphous nature, signature carbohydrate related peaks and surface morphology. Under natural conditions, pot experiments on Catharanthus roseus were conducted by supplementation of microbial consortium containing AB-13 and a previously reported AB-11 isolates. Multiple branching in shoots, roots and early flowering with delayed senescence over control plants were observed. The consortium efficiently boosted the growth of C. roseus plants with maximum shoot length of 42 ± 1.54 cm and root length of 17.05 ± 1.36 cm with an increase of 11 % and 18 % respectively as compared to control. In consortium inoculated plants, the maximum fresh weight (37.32 ± 1.78 g) and dry weight (5.77 ± 0.27 g) with an increase of fresh weight (41.55 %), dry weight (50.59 %) and total chlorophyll content (43.88 %) was recorded, as compared to control. Thus, we can conclude that the above microbial consortium promoted growth and development of economically important plant C. roseus.