Biotechnological insights into taxane biosynthesis by Cladosporium variabile: fermentation optimization, elicitation,...

Cladosporium variabile (C. variabile) is a potential taxane-producing endophytic fungus; however, its intrinsic production of anticancer taxane metabolites remains low. This investigation systematically bridges this gap by integrating biotechnological strategies e.g., optimization (including acidity, carbon and nitrogen source), elicitation, computational modeling, and molecular dynamics (MD). It was found that pH 6.0 led to the taxane fermentation of 7.4 µg gFW^- 1. Malt 5.0% (w/v) at pH 6.0 boosted the growth and taxane yield by 1.3 fold. At pH 6.0, malt 5.0% (w/v) and ammonium sulfate 5.0 mM significantly enhanced the taxane production to 24.62 µg gFW^- 1. Pectin elicitation further amplified this yield by 31-fold, achieving 233 µg gFW^- 1 at day 14. Mathematical modeling indicated that the optimal pH range for the growth and taxane fermentation was between 5.4 and 6.3. Moreover, modeling the concentrations of malt and ammonium sulfate predicted improvements in both growth and taxane yield, offering valuable approaches for medium optimization. MD simulations of taxadiene synthase (TXS) revealed key molecular interactions between TXS and pectin, particularly involving residues Lys873, Val415, Arg421, and Pro661. Root-mean-square deviation (RMSD) and root-mean-square fluctuation (RMSF) analysis determined that pectin binding significantly stabilized TXS, decreasing the average RMSD from 4.7 Å to 3.1 Å and reducing backbone fluctuations. These findings highlight the potential of optimized fermentation and sustainable elicitation strategies to address current limitations in taxane production. Furthermore, molecular dynamics simulations provided insights into key binding interactions, offering a foundation for improved biotechnological applications and sustainable platforms for taxane biosynthesis.

The online version contains supplementary material available at 10.1007/s13205-026-04704-3.