A soil pseudomonad Pseudomonas sp. strain PIN isolated by enrichment culture metabolized either alpha- or beta-pinene via p-menthene derivatives such as limonene and p-cymene. Bioconversion of alpha- and beta-pinene by resting cells represented 33.5 and 58.8% conversion yield, respectively. It was demonstrated that p-menthene derivatives except for oxygenated compounds of bioconversion products of alpha- or beta-pinenes supported good growth while bicyclic terpenes of bioconversion products had little effect on growth of this strain. The specific conversion yield was 10.2 mg/g cells with alpha-pinene and 40.7 mg/g cells with beta-pinene. This strain could utilize limonene and p-cymene as sole carbon and energy source and accumulated periilic acid from limonene and cumic acid from p-cymene, respectively. The energy yielding process of this strain indicated bioconversion of either alpha- or beta-pinene to p-menthene derivatives such as limonene, p-cymene, alpha-terpinolene as intermediates. (C) 2002 Elsevier Science Ltd. All rights reserved.