Proteomic response of himalayan psychrotrophic bacterium Pseudomonas lurida NPRP15

Low temperature proteomic response of psychrotrophic bacterium Pseudomonas lurida NPRp15 was investigated. Culture was subjected to cold shock (28°C to 4°C) and cold acclimatization at 4°C and 15°C. Subsequently bacterial cellular proteins were extracted and separated by SDS-PAGE. Statistical tools (Principal component analysis) were employed to analyze the cold induced and cold acclimatize proteins based on their variations in their expression level. Noticeable variations were observed in protein expression levels for cold shock and cold acclimatized bacterial cells. Similarly PCA analysis clearly classified four groups of proteins depending upon their expression levels. Group I contain 4 proteins that expression level was instantly higher in cold shock and referred as cold shock proteins (Csps). While, Group II contains 5 proteins categorically expressed immediately after cold shock and continuously expressed at the end suggested their role as both cold shock proteins (Csps) and cold acclimation proteins (Caps). Whereas group III contained those proteins whose expression level was not affected or slightly lowered during cold shock. Fourth group proteins expression level was found lowered and suggested their negligible roles in bacterial cold adaptation. The findings of present study indicated that psychrotrophic Pseudomonas lurida NPRp15 expressed considerably some sets unique higher molecular weight cold induced proteins that are playing vital role in bacterial cold adaptation.