In Vitro Characterization and Identification of a Plant Growth-Promoting Bacteria Consortium from Malaysian Oil Palm (Elaeis guineensis) rhizosphere as a Potential Sustainable Biofertilizer

Abstract

Reliance on chemical fertilizer has caused many challenges to soil health. The alternative to chemical fertilizer is biofertilizer that can be developed using beneficial bacteria. Thus, this study aims to characterize the potential plant growth-promoting rhizobacteria (PGPR) based on biochemical tests on bacterial isolates, and to identify the potential PGPR based on the 16S rRNA sequencing molecular method as a potential biofertilizer development. The PGPR strains were isolated from oil palm (Elaeis guineensis) rhizosphere in Universiti Teknologi MARA (UiTM) Share farm, Malacca, Malaysia on nutrient media agar. Then, the bacteria isolates were screened for nitrogen fixation, phosphate and potassium solubilization, indole-3-acetic acid (IAA) production, siderophore production and hydrolyzing enzyme production tests. The isolates AR 11 and AR 21 strains have presented the most convincing result across all tests, which showed positive results for nitrogen fixation, solubilized phosphate and potassium, and produced indole acetic acid (IAA), siderophore and hydrolyzing enzyme. The selected strains proceeded for molecular identification based on the 16S rRNA gene sequence using 1492R and 27F universal primers. The isolates AR 11 and AR 21 were identified as Acinetobacter seifertii and Aquitalea pelogenes respectively. Thus, the oil palm farming sector stands to gain from the beneficial PGPR isolate which is aligned with sustainable agriculture production and potential biofertilizer development. It also helps to reduce dependence on chemical fertilizer.