Abstract: Wood vinegar is an acidic liquid obtained from the flue gas produced during biomass pyrolysis after condensation. Acids, phenols, ketones, and furans in wood vinegar have excellent antibacterial properties, and can be used as substitutes for pesticides and fertilizers. In this paper, we reviewed the antibacterial effect and mechanism of the main antibacterial active ingredients in wood vinegar, as well as the influence of preparation methods (biomass raw materials, preparation temperature, refining method) on antibacterial components. Wood vinegar has an effective inhibition on Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, with poorer inhibitory effect on fungi than on bacteria. Wood vinegar can be antibacterial by destroying cell structure, reducing cell membrane stability, inhibiting protein synthesis and key gene expression. Biomass raw material, pyrolysis temperature, and refining methods can affect the antibacterial composition of wood vinegar. The higher concentrations of cellulose and hemicellulose in biomass, the higher the relative content of acid substances in wood vinegar. The higher concentration of lignin, the higher the relative content of phenolic substances. With the increases in pyrolysis temperature, the content of acid compounds in wood vinegar showed a trend of first increasing and then decreasing, while the content of phenolic compounds increased and then stabilized gradually. The contents of acids and ketones were negatively correlated each other. Distillation is beneficial to collect acetic acid and other carboxylic acids in wood vinegar. Membrane filtration is beneficial to collect phenol and guaiacol, and other phenolic compounds. In the future, we should focus on the development and research of efficient and convenient wood vinegar purification and separation methods, in-depth exploration of the antibacterial effect and mechanism of each component, so as to maximize the antibacterial performance of wood vinegar against different kinds of microorganisms and realize the resource utilization of agricultural and forestry wastes.

Key words: wood vinegar, antibacterial activity, purification and separation, bacterium, fungus