Biomass pyrolysis and gasification are used to efficiently convert lignocellulosic materials to a variety of products that can substitute for petrochemical-derived energy and chemicals. Tar (heavy hydrocarbons) is inevitably produced from the thermochemical processes, and is often disposed as an industrial waste, leading to environmental pollution. To utilize the tar, a facile route to fabricate porous fibrous composite with antimicrobial capability was demonstrated by electrospinning tar and polyacrylonitrile (PAN) blends. Continuous fibers with an average diameter ranging from 422 to 948 nm without beads were prepared from tar and PAN blends. The electrospun Tar/PAN nanofibers exhibited a high porosity of 51-63% with an average pore diameter ranging from 5.6 to 7.1 nm, indicating a mesoporous structure. The Tar/PAN nanofibers showed higher antimicrobial activities (up to 39%) against Gram-positive Staphylococcus aureus (S. aureus) and Gram- negative Escherichia coli (E. coli) in comparison with the neat PAN nanofibers, due to the presence of phenolic compounds in the tar. Aside from their antimicrobial capability, the electrospun nanofibers can also be applied in the manufacture of low-cost adsorption materials and carbon nanofibers. (C) 2015 Elsevier Ltd. All rights reserved.