Identification and Characterization of Aeromonas sp. KBK3 as a Multifunctional Plant Growth-Promoting Rhizobacterium from Banana

Abstract

In sustainable agriculture, plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria, that enhance nutrient availability and improve plant resilience to stress. This study was conducted to isolate and characterize PGPR from the banana (Musa sp.) rhizosphere. An efficient strain, identified as Aeromonas sp. KBK3 via biochemical tests and 16S rRNA gene sequencing, demonstrated significant plant growth-promoting traits. It showed noteworthy potassium solubilization index of 3.77 ± 0.27 and produced 11.4 ± 0.28 ppm of indole-3-acetic acid (IAA). The strain showed optimal growth at 35°C, pH 7, 0.5% NaCl, and tolerated 30% osmotic stress. Its PGPR traits include potassium and phosphorus solubilization, IAA production, extracellular enzymes such as cellulase and pectinase production, and tolerance to 30% polyethylene glycol (PEG). In addition, the strain didn’t show any phytotoxic effects towards spinach seed germination. Therefore, Aeromonas sp. KBK3 is a promising biofertilizer to increase nutrient availability and crop productivity. However, it must be validated through greenhouse and field trials for its agronomic performance.