Exo-polygalacturonase production by Penicillium roqueforti on pumpkin oil cake in solid state fermentation

The feasibility of using pumpkin oil cake (PuOC), individual and in combination with wheat bran (WB), as substrate for the production of Exo-polygalacturonase (Exo-p) by starter culture Penicillium roqueforti in solid state fermentation (SSF) has been evaluated. The kinetics of enzyme production was investigated using PuOC alone in the range from 13 to 168 h, with moisture contents varying from 44% the ability to grow and produce Exo-p activity on this substrate, reaching a maximum value of 1451.75 U/g.d.w PuOC by the 5th day of fermentation. Fermentation experiments indicated that the water activity (aw) influenced the enzyme production. A medium with aw 0.932 and the fermentation time of 5 days were selected, as these conditions resulted in the highest pectolytic activity and were used for further investigation. A next step in this research was to examine the effect of the substrate combination, PuOC with wheat bran (WB), in different ratios. The addition of WB as carbon sources was found to have a significant influence on the enzymes yields. Exo-p activities were the highest with initial water activity of a w 0.932 and PuOC supplementation with WB (1:0.67)

The effect of sulphates on partitioning of pectinases in aqueous two-phase systems

The effect of various sulphate salts on the partitioning of endo-pectinase and exo-pectinase in aqueous two-phase systems, composed of polyethylene glycol and dextran, was studied. Presence of ammonium sulphate and sodium sulphate at concentration 15 mmol/l in the system polyethylene glycol 4000/crude dextran, at tie-line length 7.44%, increased partition coefficient of endo-pectinase 1.25 and 1.2 fold, respectively. Ammonium sulphate at 15 mmol/l and sodium sulphate at 5 mmol/l enhanced partition coefficient for exo-pectinase for about 60% in comparison to the system without salts. Addition of magnesium and sodium sulphate to a final concentration of 0.3 mmol/l in the system containing polyethylene glycol 6000/dextran 500 000, at tie-line length 6.26%, increased the partition coefficient of endo activity for 95% and 32%, respectively. Both salts at the same concentration increased partition coefficient of exo activity 1.5 and 3 times, respectively, in comparison to the system without salts

Production of exo-pectinase by Penicillium roqueorti using pumpkin oil cake

Submerged fermentation (SmF) was carried out using the pumpkin oil cake (PuOC) as a substrate for the production of exo-pectinase (exo-p) by Penicillium roqueforti. PuOC was used as carbon, nitrogen and mineral source for fungi growth and exo-p production. SmF was carried out in the production medium containing 0.2% KH2PO4, 0.1% MgSO4 and 0.1% NaCl, supplemented with PuOC at 2% concentration. The obtained results show that P. roqueforti cultivated in a liquid medium in the presence of PuOC as a source of nitrogen, produced significant amount of exo-p, activity 161.03 U/ml