Pseudomonas Aeruginosa VJ003: A Potential PGPR for Rhizosphere Colonization, Plant Growth Promoting Traits, and Biofilm Formation

Abstract

Plant growth-promoting rhizobacteria (PGPR) are a broad group of soil bacteria that play a significant role in stimulating plant growth through a variety of advantageous actions. This is mostly accomplished by PGPR's successful rhizosphere colonization. In natural as well as stressed situations, the creation of biofilms by PGPR is thought to be a survival strategy that outperforms the planktonic mode of growth. Different biotic and abiotic factors impacting survival, colonization, and functions might cause inconsistent performance of microbial inoculants under field circumstances. As a result, it is anticipated that rhizobacteria with numerous PGP properties and an effective colonization capacity will perform better. We hypothesized that PGPR's capacity to create biofilms on plant roots would facilitate rhizosphere invasion. We have therefore selected a promising isolate of PGPR from the soybean (Glycine max) rhizoplane using a random screening technique. The ability to form biofilms and a range of PGP activities, such as the production of ammonia, hydrogen cyanide, phosphate solubilization, indole acetic acid, and biocontrol activity, were taken into consideration throughout the selection process. Pseudomonas aeruginosa VJ003 was identified as the selected isolate by the use of 16s rRNA partial gene sequencing. Soybean seedling roots harbored a strong biofilm formed by strain VJ003. Exopolysaccharide synthesis (1610.36 ± 1.20 µg/ml), alginate (142.34 ± 1.12 µg/ml), and cell surface hydrophobicity (45%) were among the biofilm-related characteristics displayed by VJ003. Therefore, a further criterion to choose a better rhizosphere colonizer and promote plant growth could be the production of biofilms on plant roots by promising PGPR.