The Development and study of nanogold particle biosynthesis using local microorganisms in Thailand

Abstract

The study is the development of biological methods for extracting gold from the effluents of the gold processing and gold extraction in the industries where has a very high acidity (pH 0-4). This method should be used to replace the electrochemical process and chemical method which cause the pollution of toxic substances, acid fumes and heavy metals of copper cyanide to the environments. The research started at the characterization and identification of microorganisms presented in gold contaminated water in natural source where is highly acidic (pH 2-4) and it could synthesize nanogold particles. The bacteria Bacillus sp. E201 were identified from this source and it showed its 16S rDNA gene with similarity of 95% to bacteria Bacillus thuringiensis accession no. FJ755916. It could create gold in the solution outside the cells within three days Form 1 mM HAuCl4 • 3H2O solution, the bacterial dry weight could yield 75.3% with the amount of 0.5115 grams. It could be able to withstand acidic conditions and harvest gold from the gold extraction solution after centrifugation and filtration. So this developed biological method could be developed to apply in the industrial production of gold and jewelry industry.