LAUSR

Abstract The use of new constitutive promoters and recycled carbon sources in the recombinant production of industrial proteins such as lipases in the cell factory Pichia pastoris is desirable, in order to improve production and minimize the cost of the culture medium. With this aim, the recombinant production of lipase B from Candida antarctica (rLipB) in P. pastoris under the PGK promoter, using crude glycerin from biodiesel, was assessed. Study of the best culture conditions made possible a significant increase in production. The optimal culture conditions used minimal medium containing crude glycerol as the carbon source, starting the batch with 100 g/L, and subsequently making four pulses of this crude glycerol, of 25 g/L each. The lipase produced was characterized and compared to commercially available lipase from Aspergillus niger, sold by Novozymes. rLip B proved to be stable in basic pHs and temperatures lower than 55 °C, the optimum conditions being pH 7.0 and 30 °C. The selectivity for medium-sized carbon chains was similar in both, and tributyrine (C4:0) was the best triacylglycerol studied. The results showed that this approach is a viable alternative to produce rLipB with this new promoter, using crude glycerol.