Effects of Two Different Size ZnO Nanoparticles on the Growth of <italic>Aspergillus oryzae</italic>.

Two different kinds of ZnO nanoparticles (NPs) with distinct particle sizes were synthesized by a precipitation method. For the first time, the effects of two distinct sizes ZnO NPs on the growth, photoluminescence properties and kojic acid (KA) yield of <italic>Aspergillus oryzae</italic> (<italic>A. oryzae</italic>) were examined. The findings showed that ZnO-A and -B NPs, with average particle sizes of 11.93 nm and 34.41nm, respectively, exhibited a hexagonal crystal structure. It was found that when the concentration of NPs was below 100μg/mL, ZnO NPs were nontoxic and served as activators to stimulate the growth of <italic>A. oryzae</italic>, and the biomass of solid and liquid medium, the total integral emission intensity, the content of extracellular protein and total organic carbon and KA yield of <italic>A. oryzae</italic> grown with ZnO-A (ZnO-B) NPs were about 2.19 (1.97), 2.47 (1.56), 1.67 (1.16), 2.45 (1.95), 0.47 (0.50) and 2.07 (1.37) times more than that of control sample (without NPs), respectively. [ABSTRACT FROM AUTHOR]