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

Abstract

Taxol® (generic name – Paclitaxel), the most promising chemotherapeutic agent was isolated from bark of different Taxus sp. As Taxus species are threatened with extinction (endangered in Himalaya), thus it is imperative to develop alternate and sustainable method for commercialization and scale up production of paclitaxel. In this respect, physical and chemical parameters are effective and important key points for active compound production particularly by using endophytic microbes. In the present study, five endophytic fungi isolated from the roots of Taxus wallichiana, are tested for paclitaxel production using biochemical and molecular methods. Subsequently, effect of physico-chemical parameters like temperature, pH, incubation time, and medium constituents i.e., salt concentration, carbon and nitrogen sources on paclitaxel production were also analyzed. Among isolates, two of the fungi viz. 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-deacetylbaccatin III-10-O-acetyl transferase (DBAT) and C-13 phenylpropanoid side chain-CoA acyltransferase (BAPT), implicated in paclitaxel biosynthesis. Both the endophytes showed the amplicons of DBAT and BAPT genes. Results revealed that after optimization of medium components and physical condition, paclitaxel production was increased in both the endophytes, maximum paclitaxel 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 S7 liquid medium composition.