Figure 1.
Antimicrobial activity of T. vulgaris major essential oil terpenes. Activities are shown as IC50 (relative half maximum inhibitory concentration, for actual inhibitory values see Tables S1) values (log-transformed scale and non-transformed ppm values in brackets) for M. plutonius, European foulbrood associated bacteria (B. laterosporus, B. pumilus, E. faecalis, P. alvei and P. dendritiformis) and two non-bee associated bacteria (E. coli and P. fluorescens). Values define the growth response based on growth rate and are based on 5 replicates for each species and compound. Light yellow means the substance tested showed no inhibitory effect on bacterial growth. Branch lengths in dendrograms (for bacteria and substances) produced from hierarchical cluster analysis (Manhattan distance, average linkage clustering) correspond to relative degree of similarity between branches.