Recombinant expression, characterization, and application of a phospholipase B from Fusarium oxysporum

- The Fusarium oxysporum putative lipase was identified as a PLB.
- The PLB activity obtained (6503.8 U mL−1) is the highest reported to date.
- The PLB reduced the phosphorus content of a crude oil from 75.88 ppm to 3.3 ppm.
- This study provided insights into production and application of the F. oxysporum PLB.

In this study, a gene encoding a putative lipase from Fusarium oxysporum was optimized via codon optimization and expressed in Pichia pastoris KM71. The gene product was identified as a phospholipase B (PLB). The engineered P. pastoris was further cultured in a 3.6-L bioreactor. After optimization of the induction conditions, this system produced 6.6 mg mL−1 protein and 6503.8 U mL−1 PLB activity in the culture medium. Efficient expression of this PLB in P. pastoris should reduce the costs of production and application. The purified enzyme, with a specific activity of 1170 U mg−1, was optimally active at pH 5.0 and 55 °C. The results of a degumming experiment performed using the recombinant PLB showed that the phosphorus content of a test oil was decreased from 75.88 ppm to 3.3 ppm in 2 h under optimal reaction conditions. This study provides a basis for the industrial use of F. oxysporum PLB in oil degumming applications.