Role of Cadmium and Lead Tolerant Pseudomonas aeruginosa in Seedling Germination of Rice (Oryza sativa L.)

Abstract

In the present study, cadmium and lead tolerant bacteria were isolated from contaminated crop field nearby industrial sites, garage and petrol pumps of Cachar District of Assam, India. Bacterial isolates were characterized on the basis of morphological, physiological, biochemical characteristics and 16S rDNA gene sequencing. In presence of cadmium, Pseudomonas aeruginosa SN1 and Pseudomonas aeruginosa SN3 showed the highest MIC for cadmium and lead. These two isolates were taken under consideration for pot experimental studies. After 20 days of seedling inoculation in Cd treated soil and application of P. aeruginosa SN1, it has been observed that rice plant (Oryza sativa L.) attains 10.1% (at 20 mg/kg Cd) and 18.6% (at 50 mg/kg Cd) increased shoot growth as compared to control pots without bacterial inoculation. P. aeruginosa SN1 and P. aeruginosa SN3, showed significant result at 20 mg/kg of lead in soil but, failed to show any significant response at 50 mg/kg of lead in soil. Overall study demonstrated that P. aeruginosa SN1 and P. aeruginosa SN3 could remediate cadmium and lead contaminated soil at concentration below 20mg/kg, thus dedicating sites which are set aside for long term agricultural purpose.