Oxygenated monoterpenes produced by yeasts, isolated fromIps typographus (Coleoptera: Scolytidae) and grown in phloem medium.

When yeasts associated withIps typographus beetles were grown in an aqueous phloem medium for two days, the main oxygenated monoterpenes produced were α-terpineol and borneol. Terpinene-4-ol, myrtenol, andtrans-pinocarveol were also found but in lesser amounts. Of the six strains used in this study,Hansenula capsulata andCandida nitratophila produced the largest amounts of oxygenated monoterpenes. Addition of α-pinene to the phloem medium generally reduced the amounts of oxygenated monoterpenes, probably because this substance is toxic to all tested yeast species. OurCandida diddensii strain seemed to be particularly sensitive to α-pinene. None of the yeast strains producedcis-verbenol,trans-verbenol, or verbenone from the medium or from added α-pinene.