Antibacterial Properties of Extracts from Abies holophylla and Pinus koraiensis Needles Against Escherichia coli and Staphylococcus aureus

In this study, functional substances with antibacterial properties were extracted from the needles of Abies holophylla and Pinus koraiensis , and optimized using the central composite design -response surface methodology (CCD-RSM). The optimal extraction conditions for Abies holophylla were an extraction temperature of 59.5 degrees C and an ethanol/ultrapure water volume ratio of 69.5 vol.%, resulting in an extraction yield of 13.5% and inhibition diameters of 11.6 mm against Escherichia coli ( E. coli ) and 9.3 mm against Staphylococcus aureus ( S. aureus ). For Pinus koraiensis , the optimal extraction conditions were an extraction temperature of 59.2 degrees C and an ethanol/ultrapure water volume ratio of 67.8 vol.%, resulting in an extraction yield of 4.8% and inhibition diameters of 7.9 mm against E. coli and 12.5 mm against S. aureus . The actual experimental results under these optimal conditions showed that an extraction yield from Abies holophylla needles was 13.0% and an inhibition diameter of 11.7 mm against E. coli and 9.2 mm against S. aureus , indicating an error rate of approximately +/- 2.3%. For Pinus koraiensis needles, the extraction yield was 5.1%, with inhibition diameters of 7.5 mm against E. coli and 12.3 mm against S. aureus , indicating an error rate of +/- 4.23%.