Bioremediation of heavy metal toxicity from factory effluents by transconjugants bacteria

ABSTRACT

The presence of heavy metals in aquatic environments is known to cause severe damage to aquatic life, beside the fact that these metals kill microorganisms during biological treatment of waste, water with a consequent delay of the process of water purification. Most of the heavy metal salts are soluble in water and form aqueous solutions and consequently cannot be separated by ordinary physical means of separation. Five bacterial strains were used in this study. Bacterial strains were marking using 10 antibiotics and 7 heavy metals to be use as a selectable markes in conjugation process. Mating were performed using five bacterial strains. These strains were genetically marking in relation to their tolerance to the different antibiotics and heavy metals. All matings between bacterial strains were successes. The bio-sorption capacities for all heavy metals determined were higher for some metals than others. The transconjugants strain Tr[5] resulted from mating between the parental bacterial strains [B-6bs X B-21] was more efficient in molybdenum uptake than all bacterial strains when supplemented nutrient media with wastewater. Bacterial strains [B-21] appeared a good uptake of heavy metal ions [copper, cadmium, iron, cadmium and Lead] than other bacterial strains. This work highlights the potential of bacterial strains B-21 in uptake of heavy metals. The transconjugant strain Tr[3] resulted from mating between parental bacterial strains [B-1584 X B-287] was more efficient in chromium uptake than all bacterial strains