Effectively expression of Thermomyces lanuginosus thermostable lipase in non-spore Aspergillus niger

We optimized the codon usage of Thermomyces lanuginosus lipase (tll) gene based on codon usage bias, RNA stability and free energy, and synthesized the optimized tll gene.The obtained tll gene was inserted into a clone vector, and then subcloned to the expression vector pHGWPT-tll.The vector pHGWPT-tll was transformed into non-spore Aspergillus niger SH-2 via Agrobacterium tumefaciens-mediated transformation using hygromycin B resistant gene as the selection marker.A.niger transformants bearing the tll gene, were selected by tributyrin hydrolyzing plate.The recombinant protein was verified by SDS-PAGE and Western blotting.After 72h fermentation, the lipase activity of transformants reached 36U/mL.Furthermore, the tll transformants was subjected to mutagenesis via atmospheric and room temperature plasma (ARTP) .The specific activity of the mutants was 37% higher than that of the original transformants, suggesting that tll gene could be highly expressed in A.niger.