Journal of Hazardous Materials, Vol.329, 120-130, 2017
Bioleaching of electronic waste using bacteria isolated from the marine sponge Hymeniacidon heliophila (Porifera)
The bacteria isolated from Hymeniacidon heliophila sponge cells showed bioleaching activity. The most active strain, Hyhel-1, identified as Bacillus sp., was selected for bioleaching tests under two different temperatures, 30 degrees C and 40 degrees C, showing rod-shaped cells and filamentous growth, respectively. At 30 degrees C, the bacteria secreted substances which linked to the leached copper, and at 40 degrees C metallic nanoparticles were produced inside the cells. In addition, infrared analysis detected COOH groups and linear peptides in the tested bacteria at both temperatures. The Hyhel-1 strain in presence of electronic waste (e-waste) induced the formation of crust, which could be observed due to bacteria growing on the e waste fragment. SEM-EDS measurements showed that the bacterial net surface was composed mostly of iron (16.1% w/w), while a higher concentration of copper was observed in the supernatant (1.7% w/w) and in the precipitated (49.8% w/w). The substances linked to copper in the supernatant were sequenced by MALDI-TOF-ms/ms and identified as macrocyclic surfactin-like peptides, similar to the basic sequence of Iturin, a lipopeptide from Bacillus subtilis. Finally, the results showed that Hyhel-1 is a bioleaching bacteria and cooper nanoparticles producer and that this bacteria could be used as a copper recovery tool from electronic waste. (C) 2017 Elsevier B.V. All rights reserved.