Assessment of Potential Phosphate Solubilizing Microbes Isolated from Rice Fields of Coastal Odisha Implications for Sustainable Agricultural Evolution

Abstract

Phosphorus is a vital macronutrient for rice plant growth but its availability is limited newlinedue to fixation and leaching in soil. Phosphorus scarcity in the coastal Odisha region newlineis further intensified by challenges like flooding, erosion, saltwater intrusion, and newlineclimate change . Hence, it leads to the excessive use of chemical fertilizers in rice newlinefield s with detrimental effects on soil and environment. To mitigate these issues, newlineadopting phosphate solubilizing microbes as an eco friendly alternative is newlineindispensable for sustainable agriculture Moreover this ensures phosphorus newlineavailability while also pr eserving the soil and the environment . An attempt was made newlineto isolate p hosphate solubilizing microbes from rice fields of ten coastal districts in newlineOdisha: Balasore, Bhadrak, Jajpur, Kendrapara, Jagatsinghpur, Cuttack, Khordha, newlinePuri, Nayagarh, and Ganjam. A total of 120 soil samples were collected. Soil newlineinvestigations revealed slightly acidic rhizospheric soils with low nitrogen, extremely newlinelow phosphorus, and medium potassium levels across the se districts. Microbial newlinediversity in all districts reveals varying ratios of rhizosphere bacteria to phosphate newlinesolubilizing bacteria 8:1 to 12:1 and rhizosphere fungi to phosphate solubilizing fungi newline2:1 to 4:2.Six potential bacteria PR, PD, PSB3, PSB4, PSB5, PSB19 and four fungi newlinePRF1, PRF2, PRF3, PRF4 were isolated based on their phosphate solubilizing newlinecapacity and further screened for their environmental stress resilience as well as plant newlinegrowth promoting activities. Most of the bacterial isolates were gram negative rods newlineexcept PSB19 and PSB3. Most of them exhibited posi tive results in motility, citrate newlineutilization, catalase, and oxidase activities during morphological and biochemical newlinecharacterization. Fungal isolates, stained with lactophenol cotton blue, exhibited newlinepositive hydrolysis of starch, cellulose, and lipids. 16S rRNA m olecular analysis newlineidentified potential bacteria strains PR as Klebsiella pneumoniae (KX789530), PD as newlineBurkholderia Sp. strain EIKU9 (MH201191), P