Soy proteins are gaining more and more attention because of its multifunction and biodegradability. Silver nanoparticles (AgNPs) are introduced into the nanofibers to prevent growth of microorganisms over the filter media. In the present study, the multifunctional and antimicrobial nanofibrous membranes were prepared by electrospinning the soy protein isolate (SPI)/polymide-6 (PA6)-silver nitrate system followed by ultraviolet reduction. The morphology of SPI/PA6 nanofibrous membranes was characterized by scanning electron microscopy. Antibacterial property of nanofibrous membranes were investigated against Escherichia coli and Bacillus subtilis. The optimized fiber membrane exhibited over 95% filtration efficiency of PM0.3 (particulate matter size less than 0.3 mu m). The successful synthesis of SPI/PA6-AgNPs nanofibrous membranes would make it to be the potential candidate for novel antibacterial and high-performance air filter. (C) 2017 Wiley Periodicals, Inc.