| Autor: |
Shudirman S; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM)., Abang Kassim A; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM)., Shamsol Anuar NS; Graduate School of Life and Environmental Science, University of Tsukuba., Utsumi M; Graduate School of Life and Environmental Science, University of Tsukuba., Shimizu K; Graduate School of Life and Environmental Science, University of Tsukuba., Muhammad Yuzir MA; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM)., Megat Mohd Noor MJ; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM)., Md Akhir FN; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM)., Othman N; Department of Mechanical Precision Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM)., Zakaria Z; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM)., Sugiura N; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM).; Graduate School of Life and Environmental Science, University of Tsukuba., Hara H; Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia (UTM). |
| Abstrakt: |
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, respectively. 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 ✕ 10 5 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 ✕ 10 5 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. |
