Isolation of phosphate solubilizing bacteria from the rhizosphere of local aromatic rice in Bada Valley Central Sulawesi, Indonesia

Abstract

Phosphate Solubilizing Bacteria (PSB) can be used to increase the efficiency and availability of P in the soil as it can help the process of releasing the bound of P elements so that they become available to the plants. This study aims to isolate and determine the morphological characteristics of the PSB colonies in the rhizosphere of the local aromatic rice plant, analyze the phosphate solubility of each isolate. A total of eleven rhizospheres bacterial were successfully isolated from the local aromatic rice rhizosphere. The morphological characteristics, including the size, edge, shape, elevation, and color of the colony, were obtained vary. The bacteria found were gram-positive and gram-negative, which are 81.81% and 18.18%, respectively. The result of the catalase reaction test showed 72.72% positive and 27.27% negative catalase. Furthermore, eight bacterial isolates formed a clear zone with an area of 0.84–2.66 cm. The Phosphate solubility was 116.67–133.00, and the Phosphate dissolving index was 2.17–2.33 at acidic pH between 4.27–5.67. The concentration of dissolved phosphate was 5.152 mg L−1 – 9.382 mg L−1. The results showed that the PSB has a potential being an alternative way to be developed as a biological fertilizer agent in supporting sustainable agriculture.

Growth promotion ability of phosphate‐solubilizing bacteria from the soybean rhizosphere under maize–soybean intercropping systems

“…The pH of PSBs isolated from the rhizosphere of local fragrant rice in the Bada River Valley, Sulawesi, Indonesia, was between 4.27 and 5.67 after 7 days of cultivation in liquid Pikovskaya media. 43 The pH of 76 PSBs isolated from agricultural fields (Hailun, Heilongjiang, China, and Yingtan, Jiangxi, China) were mostly between 4.37 and 8.34 after 3 days of cultivation in liquid modified PVK (without agar and indicator). 44 In this study, the pH in the solution of all strains was between 4.31 and 5.06 after 5 days of cultivation in NBRIP medium.…”

“…However, the primary reason for the dissolution of poorly soluble phosphate is that P‐solubilizing bacteria release acidic substances that lower the soil pH. The pH of PSBs isolated from the rhizosphere of local fragrant rice in the Bada River Valley, Sulawesi, Indonesia, was between 4.27 and 5.67 after 7 days of cultivation in liquid Pikovskaya media 43 . The pH of 76 PSBs isolated from agricultural fields (Hailun, Heilongjiang, China, and Yingtan, Jiangxi, China) were mostly between 4.37 and 8.34 after 3 days of cultivation in liquid modified PVK (without agar and indicator) 44 .…”

Selection of Potential Bacteria in Termite Nest and Gut for Sustainable Agriculture

“…The clear area around the bacterial culture droplets was measured. Phosphate solubilizing index (PSI) was calculated using equation [28] as follows:…”

Salinity stress mitigation on Zea mays L. seedling by halotolerant bacteria

“…The bacterial isolates in glycerol stock were grown in a nutrient agar (NA) medium for two to three days for further screening. The phosphate solubilization assay followed the method developed by Sudewi et al with modification by supplementing 600 mM NaCl to Pikovskaya liquid medium [13]. The eight bacterial cultures were inoculated to Pikovskaya liquid medium respectively, then were incubated with agitation at 150 rpm for 5 d. The supernatant was obtained by centrifugation of bacterial culture.…”