Limitation of nutrients stimulates musty odor production by streptomyces sp. Isolated from a tropical environment

• Main Authors: Shudirman, S., Kassim, A. A., Anuar, N. S. S., Utsumi, M., Shimizu, K., Yuzir, M. A. M., Noor, M. J. M. N., Akhir, F. N. M.
• Format: Article
• Language: English
• Published: Microbiology Research Foundation 2021
• Subjects: T Technology (General)
• Online Access: http://eprints.utm.my/id/eprint/94776/1/ShahirahShudirman2021_LimitationofNutrientsStimulatesMusty.pdf; http://eprints.utm.my/id/eprint/94776/; http://dx.doi.org/10.2323/jgam.2020.08.001

Musty odor production by actinomycetes is usually related to the presence of geosmin and 2-methylisoborneol (2-MIB), which are synthesized by enzymes encoded by the geoA and tpc genes, re-spectively. Streptomyces spp. strain S10, which was isolated from a water reservoir in Malaysia, has the ability to produce geosmin when cultivated in a basal salt (BS) solid medium, but no 2-MIB production occurred during growth in BS medium. Strain S10 could produce higher levels of geosmin when the phosphate concentration was limited to 0.05 mg/L, with a yield of 17.53 ± 3.12 × 105 ng/L, compared with growth in BS medium. Interestingly, 2-MIB production was suddenly detected when the nitrate concentration was limited to 1.0 mg/L, with a yield of 1.4 ± 0.11 × 105 ng/L. Therefore, it was concluded that phosphate-and nitrate-limiting conditions could induce the initial production of geosmin and 2-MIB by strain S10. Furthermore, a positive amplicon of geoA was detected in strain S10, but no tpc amplicon was detected by PCR analysis. Draft genome sequence analysis showed that one open reading frame (ORF) contained a conserved motif of geosmin synthase with 95% identity with geoA in Streptomyces coelicolor A3 (2). In the case of the tpc genes, it was found that one ORF showed 23% identity to the known tpc gene in S. coelicolor A3(2), but strain S10 lacked one motif in the N-terminus.