Abstract

Pseudomonas putida is a well-known plant growth promoting bacterium (PGPB) with the capacity to improve plant growth. The objective of this study was to assess the effect of P. putida towards plant growth and its interaction with its microbial ecosystem. P. putida strain PF1P was isolated from the rhizosphere of banana plant (Musa species). The isolated P. putida strain PF1P possess ability to secrete acetic acid (42.1 µg/mL) and gibberellic acid (10.1 µg/mL). Further study conducted showed that P. putida strain PF1P was able to increase 54.6% of fresh plant weight and 51.3% of root length for Brassica chinensis var parachinensis. Soil microbial assessment indicates that P. putida strain PF1P did not have any detrimental effects as Shannon diversity index showed an increase in the microbial diversity from 2.635 to 2.903 with the colony forming unit per gram of soil increase from 9 × 107 to 5 × 109, respectively for control and treated soil. Soil health check also showed that inoculation of P. putida strain PF1P does not cause any negative effect to the soil. Inoculation of P. putida strain PF1P proved to improve the growth of the plant and microbial diversity in the soil. Mass production of this bacterium should be studied for possible industrial application.

Key words: Encapsulation, auxin, gibberellic acid, plant growth promoting bacteria.