J. Basic Microbiol. 45 (2005) 3, 236 – 242 DOI: 10.1002/jobm.200410495 © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 0233-111X/05/0306-0236 (Department of Applied Biological Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid-22110, Jordan) Production of 2-methylisoborneol by Streptomyces violaceusniger and its transformation by selected species of Pseudomonas ISMAIL SAADOUN* (Received 03 September 2004/Accepted 08 November 2004) The effect of glucose, glycerol and yeast-extract (YE) on 2-methylisoborneol (MIB) production by Streptomyces violaceusniger (C 4 – S strain) was determined. Glycerol as a sole carbon source promoted MIB production was maximum concentration (40.65 μg/l) after 10 days incubation, while glucose favored biomass production. Increasing YE concentration from 0.1 to 1% (W/V) repressed MIB production with 62 and 83% reduction after 10 and 14 days, respectively. Transformation of this odorous compound was investigated using seven different Pseudomonas species. Action of the different Pseudomonas spp. on the C 4 – S extract was followed at 1 hour, 2 hours, 6 hours and 12 hours. Pseudomonas spp. 1, 2, 3 and 5 indicated a positive reaction; however, Pseudomonas spp. 4, 6 and 7 showed no effect. These data suggest that 2-methylisoborneol can be transformed by Pseudomonas spp. and the test adopted by this study can be applied for screening organisms for their ability to transform MIB. The naturally produced compound 2-methylisoborneol (1,2,7,7-tetramethyl-exo-bicyclo- heptan-2-ol or MIB) is one of the compounds that is most common for imparting a musty odor to drinking water. MIB is of particular concern to water managers as normal water treatment processes inefficiently remove it. To avoid consumer complaints, water authori- ties generally monitor their source water supply and implement management strategies when the concentration of this compound is still low enough to make early treatment options viable. Because MIB is difficult to remove by conventional water treatment meth- ods (LALEZARY et al. 1986), biodegradation could be an alternative means of removal that would warrant investigation. YAGI et al. (1988) reported the degradation of more than 50 percent of geosmin and MIB adsorbed onto a bio-activated carbon filter seeded with Bacillus subtilis. SAADOUN and EL- MIGDADI (1998) suggested that naturally occurring geosmin could be degraded by selected species of Gram-positive bacteria. In the present study, the method of JACOBS et al. (1983) has been modified in order to determine the ability of different Pseudomonas spp. to degrade MIB-like compounds by transforming them to alcohol. Thus, the detection of alcohol production as a result of MIB oxidation would be an applicable approach for detecting the activity of microorganisms on this volatile compound. This technique proved to be simple, rapid and suitable for primary, semi-quantitative screening of organisms capable of ethanol production. SAADOUN and EL- MIGDADI (1998) applied this technique for the screening of bacteria that degrade geosmin- like compounds. MIB was produced by Streptomyces violaceusniger in laboratory culture conditions to be used in the degradation study. * Corresponding author: Dr. I. SAADOUN; e-mail: isaadoun@just.edu.jo