Isolation and purification of bacteria from bauxite and iron ore mine samples

Abstract

Biobeneficiation involves the selective removal of undesirable mineral constituents from an ore through interaction with microorganisms, enriching the solid residue with respect to the desired mineral phase. Biomineral beneficiation can be defined as a beneficiation process brought about by microorganisms which mediate in a number surface chemical and physico-chemical phenomena such as Alteration of surface chemistry of minerals. Generation of surface active chemicals Selective dissolution of mineral phase in an ore matrix, and Sorption, accumulation and precipitation of ions and compounds. Several types of autotrophic and heterotrophic bacteria, fungi, yeasts and algae are implicated in mineral beneficiation process. Bacterial cells are grown in the presence of sulphide minerals such as pyrite, galena and chalcopyrite. Electrostatic, hydrophobic, chemical and other short and long range forces are involved are responsible for bacterial adhesion on mineral surfaces. Cell surface hydrophobicity is often governed by the chemical composition and physical arrangement of cell wall outer layers.surface protein and polysaccharides are involved in bacterial adhesion. For example, Rhamnose-rich polysaccharides are involved in the hydrophobic adhesion of Rhodococcus species. Cell surface hydrophobicity is not a permanent attribute of the cell envelope, but could be modified to suit changing environmental conditions and other physiological factors. Adhesion may also allow better interaction and utilisation of nutrients available on substrates. Bacterial adhesion is dependent not only on the biochemical and surface chemical properties of the organism but also on the interfacial and surface properties of the mineral in aqueous system. The polar flagellum of the bacteria acts as a locomotor organ. When grown in a liquid nutrient medium, the cells acquire appropriate surface properties to survive in a liquid medium, while if grown on a solid substrate, would orient themselves accordingly. Similarly, many microbial species omnipresent in the mines are capable of generating biopolymers that’s helps in mineral flotation and ore solubilisation. The objective of this work was to isolate bacterial species from samples of Bauxite and Iron ore mines.