Production of Taxol by Endophytic Fungi Isolated from Roots of Himalayan Yew (Taxus wallichiana Zucc.)

Abstract

Taxol® (generic name – Paclitaxel), the most promising chemotherapeuticagent was isolated from bark of different Taxus sp. As Taxus species arethreatened with extinction (endangered in Himalaya), thus it is imperativeto develop alternate and sustainable method for commercialization and scaleup production of paclitaxel. In this respect, physical and chemical parametersare effective and important key points for active compound production par-ticularly by using endophytic microbes. In the present study, five endophyticfungi isolated from the roots of Taxus wallichiana, are tested for paclitaxelproduction using biochemical and molecular methods. Subsequently, effectof physico-chemical parameters like temperature, pH, incubation time, andmedium constituents i.e., salt concentration, carbon and nitrogen sources onpaclitaxel production were also analyzed. Among isolates, two of the fungiviz. GBPI TWR F1 (Penicillium sp.) and GBPI TWR F5 (Aspergillus sp.)were found to be paclitaxel producing. The genomic DNA samples were sequenced to confirm the presence of two genes viz. 10-deacetylbaccatinIII-10-O-acetyl transferase (DBAT) and C-13 phenylpropanoid side chain-CoA acyltransferase (BAPT), implicated in paclitaxel biosynthesis. Boththe endophytes showed the amplicons of DBAT and BAPT genes. Resultsrevealed that after optimization of medium components and physical condi-tion, paclitaxel production was increased in both the endophytes, maximumpaclitaxel production i.e., 5.45 ± 0.98 mg/L was obtained by GBPI TWR F5(Aspergillus sp.) following 10 days of incubation at 15◦C in optimized S7liquid medium composition