Biochemical Traits and Biological Assessment of Indigenous Biofilm-Forming Rhizophosphate Bacteria Isolated from Salinity and Acidity Stressed Soils to Enhance Maize Growth

Abstract

Soil acidity and salinity stress significantly affect nutrient availability and uptake, as well as the growth, development, and yield of maize plants. This research aimed to screen, characterize, and assess the ability of selected indigenous biofilm-forming rhizophosphate bacteria (BFRB) to produce growth factor and promote maize growth. Soil samples were collected from both acid ecosystems (AE) and saline ecosystems (SE). Thirty isolates of rhizophosphate bacteria were obtained based on the clear zone around colonies on selective Pikovskaya agar media. Subsequently, a qualitative biofilm test was conducted, resulting in the identification of 9 isolates of biofilm-forming rhizophosphate bacteria. Biochemical test was performed to asses phosphate solubility index (PSI) and production of indole acetic acid (IAA) and biological assays was performed to measure the effect of selected BFRB on maize growth characteristics. The experiment was arranged in a randomized block design with 10 treatments (control and 9 isolates of BFRB) and 3 replications. The findings revealed that all isolate has avaibility to membentuk biofilm dan mampu melarutkan P. three potential isolates of BFRB from both AE and SE significantly enhanced maize growth. Isolates PS-03, PN-05, and PC-04 from saline soils, as well as isolates NA-01, NG-04, and NF-04 from acid land, exhibited notable increases in root length, plant height, and dry weight compared to the control. For instance, isolates PS-03, PN-05, and PC-04 from saline soils increased maize height by 2160.87% and root length by 392.64%, and they also increased the dry weight of the plants by 20.50%. Similarly, isolates NA-01, NG-04, and NF-04 from acid soil increased maize height by 673.82% and root length by 220.29%, and they increased the dry weight of the plants by 12.57%. These findings suggest that these BFRB isolates hold significant potential for developing rhizophosphate biofilm biofertilizers to enhance maize productivity in marginal soils. Additionally, each of these bacteria produced IPF and IAA, which contributed to the significant increases in plant height and root length, and formed biofilms that were present on the roots of the maize plants. Therefore, field trials are necessary to utilize these bio-phosphate fertilizers to improve fertilization efficiency and maize productivity in saline and acidic ecosystems.

Keywords

• acid soils
• marginal soils
• saline soils
• salinity
• biofilm rhizophospahate biofertilizers
• bfrb