Functional diversity of culturable phosphate solubilizing fluorescent pseudomonads

Abstract

Fluorescent pseudomonad bacteria were isolated from different strawberry fields in Srinagar and Baramulla districts of Kashmir, India. The isolates were compared with a standard isolate obtained from Biofertilizer Production Laboratory, Marathwarda Agricultural University, Parbani, Maharashtra, India, for various beneficial activities. Screening of the isolates showed that significantly higher IAA (36.08 µ mol ml-1) was produced by isolate PS8, siderophore, HCN and ammonia was produced by all barring PS3, PS7 and PS9. ACC deaminase activity was shown by PS1, PS7 and PS10. Significantly higher protease (516.12 µ mol ml-1), chitinase (6.8 µ mol ml-1) and pectinase (138.16 activity of Polygalacturanase unit ml-1) was exhibited by PS1.The isolate PS2 showed higher antagonistic potential against Fusarium sp. All the isolates except PS3, PS7, PS9 and PS16 solubilized insoluble phosphorus while as 17 isolates barring PS3, PS7 and PS9 solubilized zinc, iron and potassium.Statistically significant quantities 7.42 (µgml-1) and 60.35 (µgml-1) of sparingly soluble phosphate was solubilized by the isolate PS6 after 2 and 10 days of incubation respectively, simultaneously the pH of growing medium was reduced from 6.5 to 5.3 by the isolate PS6 after 10 days of incubation. All the isolates except PS7, PS11 and PS16 utilized eleven different sources of carbon and the numerical taxonomy of isolates depending on their carbon source utilization profile resulted into two major phenons at 0.27 similarity coefficient level.