Genome characterization of Acinetobacter species from the rice rhizosphere: a potential plant growth promoting rhizobacteria (PGPR).

Abstract

Plant-microbe interactions in the rice rhizosphere play a pivotal role for crop productivity. Acinetobacter spp. are known for their plant growth-promoting (PGP) abilities, including phytostimulation, phosphate solubilization, and siderophore production. In this study, we isolated the bacterial strain Acinetobacter lwoffii DJPGP01 from rice rhizosphere soil and conducted comprehensive genome sequencing and analysis. Techniques included serial dilution for bacterial isolation, genomic DNA purification, and Illumina sequencing followed by whole genome data analysis. Genome assembly was performed using multiple assemblers with subsequent annotations through PROKKA and RAST, while pathway analysis utilized KEGG-KAAS server. The genome assembly revealed a high-quality sequence of 3.2 Mb with substantial coverage and a GC content of 43.06%. Species identification confirmed as Acinetobacter lwoffii, closely related to Acinetobacter lwoffii strain DSM 2403 based on 16S rRNA analysis. Antismash analysis identified five secondary metabolite gene clusters, potentially linked to PGP traits. Comparative genome analysis provided insights into the phylogenetic placement of Acinetobacter lwoffii DJPGP01 within its genus, showing a close relationship with Acinetobacter lwoffii NCTC 5866 based on digital DNA-DNA hybridization (DDH). The genome data underlines the potential of Acinetobacter lwoffii as a PGP agent, highlighting specific genes involved in nitrogen assimilation, phosphate uptake, and stress response mechanisms. This study contributes to our understanding of the Acinetobacter role in agricultural settings, suggesting strategies for enhancing crop resilience and productivity.