Antibacterial activity of the biogenic volatile organic compounds from three species of bamboo

Plant biogenic volatile organic compounds (BVOCs) possess ecological functions in antimicrobial benefits and air purification. The objectives of the study were to determine the differences in antimicrobial capacity of bamboo forests at different sampling sites. Three common bamboo species-<i>Phyllostachys edulis, Bambusa emeiensis</i>, and <i>Phyllostachys violascens</i>-were selected to determinate the antimicrobial activity of bamboo forests as well as under <i>ex vivo</i> conditions. Natural sedimentation method was used to determine the microbe counts in bamboo forests, and the microbe counts in grassland in the same area was measured as control treatment. The results showed that except for the <i>P. violascens</i> in Ya'an, the airborne microbial content of the sampling sites in bamboo forests was significantly lower relative to that of grassland in the same area, and inhibition rate reached 74.14% in the <i>P. violascens</i> forest in Dujiangyan. <i>P. edulis</i> forest and <i>P. violascens</i> forest in Ya'an had significantly lower inhibition rates than the other sampling sites, and there was no significant difference in the inhibition rates among the rest of the bamboo forest. The bacterial inhibition rate of bamboo leaves under <i>ex vivo</i> conditions varied with bamboo species and bacterial strains, with higher antibacterial activity against Gram-negative bacteria overall. <i>Escherichia coli</i> was sensitive to <i>B. emeiensis</i> leaves, while <i>Staphylococcus aureus</i> and <i>Bacillus subtilis</i> were sensitive to <i>P. violascens</i> leaves. Moreover, <i>Candida albicans, S. cremoris</i>, and <i>Shigella Castellani</i> were sensitive to <i>P. edulis</i> leaves. An analysis of the BVOCs composition from <i>P. edulis</i> collected in Changning by SPME-GC/MS revealed that the relative content of ocimene was obviously higher than other components. This study showed that <i>P. edulis</i> BVOCs have strong inhibitory ability to the tested microorganisms, and its main constituent, ocimene, has health benefit. <i>P. edulis</i> has the potential to become a forest recreation bamboo species.