| dc.description.abstract | Heavy metal contamination has become a major threat to the environment as well
as to mankind. Bacteria demonstrate a considerable resistance to heavy metals
because of evolved metal resistance. Hence, it would be useful to identify metal
resistant bacteria to be used in mitigating metal pollution. This study was carried
out for the isolation, molecular characterization and determination of
bioremediation capacity of a bacterial strain. Metal tolerant bacterial strains present
in a textile industry effluent were screened on LB agar plates. Well isolated bacterial
colonies were screened for heavy metal resistivity by observing their growth in
media containing heavy metals. The bacterial strain TWSL_1, which grew well (p<
0.0001) in metal spiked media was selected for further analysis and it’s heavy metal
tolerance was determined by observing the growth with time by measuring the
optical density at 600 nm using a scanning UV-VIS spectrophotometer. Heavy metal
removal ability was determined by measuring metal concentrations using AAS.
Bioremoval (p<0.05) of TWSL_1 was 65.85±1.85%, 43.07±1.70% and 70.98±1.41%
for Cu2+, Cd2+ and Pb2+ respectively and the highest MIC was for Pb2+ (1200 mg/L).
To molecular characterize the isolate TWSL_1, the 16S rRNA gene sequence of
extracted genomic DNA was amplified using universal primers and the amplified
product (~1500 bp) was sequenced and analysed. The sequence was found to be
similar (97%) to 16srDNA sequence of Staphylococcus warneri strain RED5B
(Accession No: MW144878.1) in the NCBI database. Whole genome sequencing was
carried out using next generation sequencing followed by De Novo assembly. The
isolate TWSL_1 was reconfirmed as Staphylococcus warneri and annotation data
revealed the presence of several genes encoding proteins involved in heavy metal
tolerance.
Keywords: Staphylococcus | en_US |
