Screening, characterization and biofilm formation of nickel resistant bacteria isolated from indigenous environment
Hafiz Z Wadood, Anjum N Sabri Pol J Microbiol 2013; 62 (4): ICID: 1087844 Article type: Original article IC™ Value: 10.00
Abstract provided by Publisher
A total of six nickel resistant bacteria (ZB, ZC, ZD, ZL, ZK and S1X) were isolated from industrial effluents and corroded iron pieces from indigenous environment of Punjab, Pakistan. These six bacteria could tolerate nickel metal at different levels with ZB, ZC, ZD, ZL, ZK, and S1X having 233, 225, 267, 233, 228 and 296 mM minimum inhibitory concentration (MIC) of nickel metal, respectively. These bacteria were sensitive to Cu+2, Cr+3, Co+2, and Al+3 as they did not grow even at 1 mM concentration of all these metals in minimal medium, whereas all of them were resistant to Fe+3 upto 1.3 mM in minimal medium. The most suitable temperature for nickel resistant bacteria was found to be 37 °C and all of them showed maximum growth at pH 8.These bacteria were identified morphologically and biochemically. Biofilm forming ability of the bacteria was checked with and without nickel stress and it was found that strains ZK and S1X were able to form a compact biofilm even under nickel stress. The 16S rRNA-encoding genes from these bacteria were sequenced to confirm the identity of these isolates. Four different genera (Bacillus, Cronobacter, Pseudomonas and Klebsiella) of bacteria were identified by 16S rDNA genes amplified from genomic DNA of nickel resistant bacterial isolates.