STUDIES ON PHOSPHATE SOLUBILIZING POTENTIAL OF MARINE PSEUDOMONAS ISOLATES

Abstract

Phosphorus is one of the essential macronutrients in plant nutrition and is involved in many processes, including energy transfer reactions, development of reproductive structures, crop maturity, root growth and protein synthesis. The fertile cultivable soils rapidly becoming saline and alkaline due to non-judicious irrigation and application of chemical fertilizers in soils making the essential nutrients like phosphorous unavailable to plants. It triggered an urgent need to develop a phosphate solubilizing microbial (PSM) bio - fertilizer that can be used in saline and alkaline soils. Marine environment is one of the most diverse habitats with respect to its characteristic biotic and abiotic content. Marine bacteria are known for their adaptability to extreme environments with saline and alkaline conditions. The present study deals with the isolation, characterization and investigation of phosphate solubilizing ability of marine Pseudomonas isolates. Four Pseudomonas isolates were obtained by screening using Pikovskayas agar medium and identified on the basis of cultural, morphological and biochemical characterization. The phosphate solubilization activity determined by measuring the diameter of zone of solubilization and quantity of soluble phosphate released in the medium. Pseudomonas RSML04 is found to be more significant phosphate solubilizer, exhibiting 04 phosphate solubilization index and 68 ppm release of phosphate. Pseudomonas RSML04 showed a potential to be used as PSM under saline and alkaline conditions.