Identification Of A Unique Mechanism Of Tolerance Against Nickel In Bacillus Cereus Isolated From Heavy Metal Contaminated Sites.

Abstract

Bacillus cereus is rod-shaped, Gram-positive, sporulating, aerobe or facultative anaerobe. A Bacillus cereus strain, CMG2K4 was isolated from metal contaminated soil sample. CMG2K4 showed tolerance against nickel chloride up to the concentration of 10 mM. Growth curve pattern has indicated constitutive nature of tolerance and absence of plasmid revealed chromosomally located genes of tolerance. SDS-PAGE of Bacillus cereus cell lysate grown in presence of 1 mM of nickel chloride showed overproduction of ~36kDa protein. Based on N-terminal sequencing and Mass spectrometry fingerprinting this protein was identified as flagellin. Over-expression of flagellin in Bacillus cereus, CMG2K4 has pointed out a role of this protein in nickel tolerance. Potential benefits of flagellin include increased efficiency of nutrient acquirement and prevention of toxic substances to them.