A rapid biosynthesis of fluorescent CdSe QDs in Bacillus licheniformis and correlative bacterial antibiotic change assess during the process.

Cadmium selenide (CdSe) quantum dots (QDs) were quickly biosynthesized in total 18 hrs in Bacillus licheniformis ATCC 11946 (B. licheniformis), which process benefited from the cellular machinery of bacterial metal metabolism, where inorganic Na2 SeO3 and CdCl2 were chosen as raw materials to produce high quality CdSe QDs by a designed two step protocol. Research outcomes demonstrated that the purified CdSe QDs possessing maximum fluorescence intensities at weak alkalinity solutions had good fluorescence stabilities at 4 °C as well as at room temperature for a week stand. Moreover, concentration of glutathione (GSH) and content of super oxide dismutase (SOD), both of which were reported to be greatly related to biosynthetic activities in some bacterial matrices, were tracked during the biosynthetic process in B. licheniformis. Bacterial resistance researches further proved that the change rates of bacterial inhibition zone diameter to seven different antibiotics were less than 9 % after the B. licheniformis was used to manufacture CdSe QDs, showing a relative lower environmental risk in short term heavy metal exposure.