Engineering of a Microbial Cell Factory for the Extracellular Production of Catalytically Active Phospholipase A2 of Streptomyces violaceoruber

Phospholipase A 2 (PLA 2 ) from Streptomyces violaceoruber is a lipolytic enzyme used in a wide range of industrial applications including production of lysolecithins and enzymatic degumming of edible oils. We have therefore investigated expression and secretion of PLA 2 in two workhorse microbes, Pichia pastoris and Escherichia coli . The PLA 2 was produced to an activity of 0.517 ± 0.012 U/ml in the culture broth of the recombinant P. pastoris . On the other hand, recombinant E. coli BL21 star (DE3), overexpressing the authentic PLA 2 (P-PLA2), showed activity of 17.0 ± 1.3 U/ml in the intracellular fraction and 21.7 ± 0.7 U/ml in the culture broth. The extracellular PLA 2 activity obtained with the recombinant E. coli system was 3.2-fold higher than the corresponding value reached in a previous study, which employed recombinant E. coli BL21 (DE3) overexpressing codon-optimized PLA2. Finally, we observed that the extracellular PLA 2 from the recombinant E. coli P-PLA 2 culture was able to hydrolyze 31.1 g/l of crude soybean lecithin, an industrial substrate, to a conversion yield of approximately 95%. The newly developed E. coli -based PLA 2 expression system led to extracellular production of PLA 2 to a productivity of 678 U/l·h, corresponding to 157-fold higher than that obtained with the P. pastoris -based system. This study will contribute to the extracellular production of a catalytically active PLA 2 .