Inorganic Phosphate Solubilization by a Novel Isolated Bacterial Strain Enterobacter sp. ITCB-09 and Its Application Potential as Biofertilizer

Abstract

The excessive use of fertilizers in agriculture is mainly due to the recognized plant requirements for soluble phosphorus. This problem has limited the implementation of sustainable agriculture. A viable alternative is to use phosphate solubilizing soil microorganisms. This work aimed to isolate inorganic phosphorus-solubilizing bacteria from the soils of agroecosystems, to select and identify, based on sequencing and phylogenetic analysis of the 16S rRNA gene, the bacterium with the highest capacity for in vitro solubilization of inorganic phosphate. Additionally, we aimed to determine its primary phosphate solubilizing mechanisms and to evaluate its effect on Habanero pepper seedlings growth. A total of 21 bacterial strains were isolated by their activity on Pikovskaya agar. Of these, strain ITCB-09 exhibited the highest ability to solubilize inorganic phosphate (865.98 µg/mL) through the production of organic acids. This strain produced extracellular polymeric substances and siderophores that have ecological implications for phosphate solubilization. 16S rRNA gene sequence analysis revealed that strain ITCB-09 belongs to the genus Enterobacter. Enterobacter sp. ITCB-09, especially when immobilized in beads, had a positive effect on Capsicum chinense Jacq. seedling growth, indicating its potential as a biofertilizer.

Growth Enhancement of Arabidopsis (Arabidopsis thaliana) and Onion (Allium cepa) With Inoculation of Three Newly Identified Mineral-Solubilizing Fungi in the Genus Aspergillus Section Nigri

“…Notably, phosphorus is the most important key element in terms of the nutrition of plants and is found abundantly in soil; however, it is mostly present in insoluble forms. Therefore, several previous studies have focused on mineral-solubilizing fungi for the solubilization of insoluble phosphorus minerals (Sharma et al, 2013;Alori et al, 2017;Mendoza-Arroyo et al, 2020). The phosphate solubilization indices on the agar plates of A. chiangmaiensis (SDBR-CMUI4 and SDBR-CMU15), A. pseudopiperis (SDBR-CMUI1 and SDBR-CMUI7), and A. pseudotubingensis (SDBR-CMUO2, SDBR-CMUO8, and SDBR-CMU20) in this study, along with the relevant SI values, were characterized as the medium solubilization activity (SI values between 1.0 and 2.0).…”

Seed bio-priming with tri-species consortia of phosphate solubilizing rhizobacteria (PSR) and its effect on plant growth promotion

“…etc.) of maize and other plant rhizosphere formed halo zone ranging from 10 to 19 mm on Pikovskayas medium with TCP [ 36 , 37 , 38 ]. Kumar et al.…”

Biofertilizers and Biocontrol Agents for Agriculture: How to Identify and Develop New Potent Microbial Strains and Traits

“… A thorough analysis of the capacity of the strains to enhance plant health and growth under several growth conditions should become a routine in biofertilizer and biocontrol agent discovery. There are frequent reports in the scientific literature on new potent strains identified, but usually they are only tested in the laboratory conditions for few of the well-known microbial traits, and in one or two plant-growth conditions [ 144 , 145 ]. The effects of inoculants need to be tested under stressful conditions, along with an analysis of changes in the microbiome of the holobiont.…”