The intracellular proteomes of the Penicillium chrysogenum throughout pilot and industrial processes were investigated by using 2-DE combined with MALDI-TOF-TOF MS, respectively. We detected a total of 223 spots corresponding to 154 proteins and 231 spots corresponding to 157 proteins throughout pilot and industrial processes, respectively. The levels of glyceraldehyde-3-phosphate dehydrogenase increased (5.1- and 2.5-fold) under the pilot process, while its levels were no significant changes under the industrial process at 140 and 170 h when compared with that at 2 h. The levels of isocitrate lyase and fumarate hydratase were increased significantly under the industrial process, while their levels had no obvious changes after 20 h of fermentation throughout the pilot process. These results indicate that there were remarkable differences in carbohydrate metabolism (including glycolysis, gluconeogenesis, pentose phosphate pathway, and tricarboxylic acid cycle) of P. chrysogenum during the pilot and industrial fermentations, which likely result in alterations of the primary metabolism and penicillin biosynthesis. Moreover, the differences in the levels of proteins involved in amino acid metabolisms (including valine, cysteine, and α-aminoadipic acid biosynthesis) indicated that the pilot and industrial processes influenced the supplies of penicillin precursors. Compared with that at 2 h, the maximum levels of superoxide (6.9-fold, at 32 h) and catalase (9-fold, at 80 h) during the industrial process and the maximum levels of superoxide (1.2-fold, at 20 h) and catalase (7.7-fold at 128 h) during the pilot process revealed the significant difference in cell redox homeostasis and stress responses during scale-up fermentation. Particularly, 10 spots corresponding to isopenicillin N synthetase and 4 spots corresponding to isopenicillin N (IPN) acyltransferase in pilot and industrial processes were identified, respectively. The levels of IPN acyltransferase (spots 197 and 198) and CoA ligase at 80 h during the industrial process were around 2-fold of that during the pilot process, indicating that the industrial process with a higher penicillin production per cell might provide available environments to induce over-expression of IPN acyltransferase and accelerate penicillin formation. These results provide new insights into the globally potential responses of P. chrysogenum to variations of environments in different fermentation scales so as to consequently regulate the penicillin production.
Keywords: Industrial fermentation; Penicillin; Penicillium chrysogenum; Proteome analysis.