Biosorption of copper by Ochrobactrum sp. isolated from Khor Mousa sediments in Persian Gulf

Abstract

Introduction: The pollution of the marine ecosystems with heavy metals is one of the serious
effect of industrialization and development of human society. For exploitation of marine
sources and constant development, it’s necessary to invent modern methods for removal of
heavy metal pollution. In present study to assess the possibility of removing copper, we aimed
to investigate isolation and identification of resistant bacteria and determine their potential to
adsorb copper through biosorption.
Materials & Methods: Sediment samples were collected from 3 stations at Khor Mousa and
cultured on nutrient agar medium containing different concentrations of copper. Two copper
resistance (100 ppm) bacterial strains were isolated and identified through biochemical tests
and 16S rRNA analysis. Also bacterial behaviors in adsorbtion of copper were studied.
Results: Both strains belonged to Ochrobactrum genus and were gram-negative, catalase and
oxidase positive. Different characteristics of bacteria were observed in PD (phenylalanine
deaminase), NaCl and Ureas tests. Biosorption measurements showed that strains could adsorb
more than half of copper in various concentrations in 150 minutes. The bacterial behaviors
were the same in 50 ppm concentration. %73.5 and %72.6 of copper were adsorbed by strains
O. tritici strain AN4 and O. anthropi strain YX0703 respectively. However, O. anthropi strain
YX0703 reduced the copper concentration from 200 ppm to 72.08 ppm in 150 minutes and
showed the highest copper biosorption.
Conclusion: The results of present investigation showed that both mentioned bacteria have high
ability to remove copper and we can use the potential of this group of bacteria for removal of heavy
metal pollution in Persian Gulf.