Effects of culture conditions of Pseudomonas aeruginosa strain RB on the synthesis of CdSe nanoparticles.

Cadmium selenide (CdSe) was synthesized by Pseudomonas aeruginosa strain RB in a culture containing lactic acid as a carbon source, 1 mM selenite, and 1 mM cadmium under various conditions. High purity (1.02-1.16 of the atomic ratio of Se to Cd) and efficient synthesis of biogenic CdSe nanoparticles were observed at 25-30°C, 0.05-10 g L(-1) NaCl, and neutral pH conditions compared with other tested conditions. However, the size and shape of synthesized CdSe nanoparticles were not changed by changing culture conditions. The contents of S and Se in the particles respectively increased under alkaline and weak acidic conditions. Furthermore, high temperature (>37°C), high salinity (>10 g L(-1) NaCl), and alkaline pH affected the CdSe-synthesizing rate by strain RB. This report is the first optimizing the culture conditions for synthesizing biogenic CdSe nanoparticles in a batch processing.