Expression of Pisum sativum defensin 1 (Psd1) in shaking flasks and bioreactor cultivations of recombinant Pichia pastoris at different pHs

Abstract

-The methylotrophic yeast Pichia pastoris was used to produce the recombinant Pisum sativum defensin (rPsd1), a small peptide from pea seeds that has a high level of antifungal activity. The plasmid rPsd1/pPIC9 was integrated into the yeast genome and methanol was used to induce expression and secretion of the recombinant Psd1, at 30 C in a fed-batch mode. The effects of different pH conditions and process scale-up were evaluated using a Monod-type model where dissolved oxygen was considered the limiting substrate. Parameter estimation showed that the process could be improved by expressing rPsd1 in a 1000 mL bioreactor at pH 4. Structural and functional analyses revealed that the recombinant Psd1 is very similar to the native one.

Natural Antifungal Peptides/Proteins as Model for Novel Food Preservatives

“…For instance, a recombinant defensin from the leguminous weed Tephrosia villosa , active against F. oxysporum and F. moniliforme (Vijayan, Guruprasad, & Kirti, ), has been overexpressed in tobacco. Several other defensins, expressed in recombinant plants and fruits presenting PTMs such as disulfide bonds, show similar activity to the native peptides (rPsd1, rTvD1) and pH and heat stability (Larentis et al., ; Meneguetti et al., ).…”