Abstract:
Heavy metal contamination now a day is one of the major global environmental concern
and the main sources of heavy metal contamination are either natural or anthropogenic. Industrial
wastewater is commonly used for irrigation in most of the developing third world countries. As
the number of industries is being increased day by day in the modern world, with this the
concentration of heavy metals is also being increased. Several studies have been conducted to
elaborate the effects of these heavy metals on living organisms including animals, plants and
human. This study aims to isolate, identify some indigenous heavy metal tolerant (HMT)
bacteria from textile effluents and to evaluate their biosorptive potential. Three indigenous
isolates were screened out showing maximum tolerable concentration (MTC) and multi metal
resistance (MMR) to Ni and Co at different levels and were given name as AMIC1, AMIC2 and
AMIC3. Molecular characterization confirmed that AMIC1 was (K. variicola, accession number
LT838344) while AMIC2 and AMIC3 were (B. cerus accession numbers LT838345 and
LT838346 respectively). Biosorptive potential was accessed using Inductively Coupled Plasma-
Optical Emission Spectroscopy (ICP-OES) and it was found that AMIC1 reduced (49%, 50%) of
Ni after 24 and 48 hours respectively and (68.6%, 71%) of Co after 24 and 48 hours respectively.
Similarly AMIC2 reduced (48.4%, 49%) of Ni after 24 and 48 hours respectively and (70.6%,
73.6%) of Co after 24 and 48 hours respectively. AMIC3 reduced (51.8%, 50.6%) of Ni after 24
and 48 hours respectively and (73.2%, 71.8%) of Co after 24 and 48 hours respectively. Fourier
transform infrared spectroscopy (FT-IR) was used to analyze the functional groups and overall
nature of chemical bonds in bacterial strains while Scanning Electron Microscope (SEM) was
performed to detect outer morphological changes in the bacteria in response to metal stress. So it
can be concluded that all three bacteria possessed significant bioremediation potential which
could be utilized for the development of bioremediation agents to detoxify textile effluents at
industrial surroundings in the natural environments in Pakistan.
