A novel and robust recombinant Pichia pastoris yeast whole cell biocatalyst with intracellular overexpression of a Thermomyces lanuginosus lipase: preparation, characterization and application in biodiesel production.

A novel and robust recombinant Pichia pastoris yeast whole cell catalyst (WCC) with functional intracellular expression of Thermomyces lanuginosus lipase (Tll) was constructed and characterized for biodiesel production from waste cooking oils. This permeabilized WCC was able to convert waste cooking oils to biodiesel with 82% yield within 84 h at 6% dosage whole cells. The WCC showed two fold catalytic activity of 0.73 U/mg DCW compared to its commercial counterpart Lipozyme TLIM (immobilized Tll). Short chain alcohol tolerance of this WCC was significantly improved compared to Lipozyme TLIM. This beneficial property enabled it to catalyze biodiesel production efficiently with one step addition of methanol. The reusability of this biocatalyst retained 78% activity after three batch cycles. This easily prepared and cost-effective WCC showed better catalytic performance than Lipozyme TLIM with respect to biodiesel yield and productivity, thus suggesting a promising cost-effective biocatalyst for biodiesel production.