Novel Microbial Sources of Tropane Alkaloids: First Report of Production by Endophytic Fungi Isolated from Datura metel L.

Eighteen endophytic fungi were isolated from various tissues of Datura metel and genes encoding for putrescine N-methyltransferase (PMT), tropinone reductase 1 (TR1) and hyoscyamine 6β-hydroxylase (H6H) were used as molecular markers for PCR-based screening approach for tropane alkaloids (TAs) producing endophytic fungi. These fungi were identified taxonomically by sequence analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) and also based on morphological characteristics of the fungal spore as Colletotrichum boninense, Phomopsis sp., Fusarium solani, Colletotrichum incarnatum, Colletotrichum siamense and Colletotrichum gloeosporioides. The production of TAs hyoscyamine and scopolamine by the fungi has been ascertained using chromatography and spectroscopy methods by comparison with the standards. Among the fungi, the highest yields of hyoscyamine (3.9 mg/L) and scopolamine (4.1 mg/L) were found in C. incarnatum culture. This is the first report of endophytic fungi possess the PMT, TR1 and H6H genes and produces TAs. These endophytic fungi have significant potential to be applied in fermentation technology to meet the demands for TAs economically.