Increased production of alkaline polygalacturonate lyase in the recombinant Pichia pastoris by controlling cell concentration during continuous culture

Cloning, expression and characterization of a pectate lyase from Paenibacillus sp. 0602 in recombinant Escherichia coli

“…[17], the extracellular Pel production achieved in the present study exhibited an 8.54-fold increase, and the secretory capability increased from 69.3 to 89.2%. Pels have also been expressed in other expression systems, such as B. subtilis [18,19] and Pichia pastoris [20,21], among which the highest yield reported previously was 2,138 U mL −1 in B. subtilis after 44-h cultivation in a 7.5-L fermentor [22]. This is 1.15-fold lower than the production reported in this study.…”

“…In the standard condition, the assay mixtures containing 2 mL of 0.2% (w/v) PGA in PL buffer (50 mM glycine–NaOH buffer, pH 9.8) supplemented with 0.5 mM CaCl 2 were incubated for 15 min at 45°C, and 3 mL of 50 mM phosphoric acid was added immediately to terminate enzymatic reactions. The absorption at 235 nm, indicating the formation of unsaturated products, was spectrophotometrically measured [21]. One unit of enzymatic activity was defined as the amount of enzyme that produced 1 μmol of unsaturated product per minute under the above-mentioned assay conditions.…”

High‐level extracellular expression of inulin fructotransferase in Pichia pastoris for DFA III production

“…The results suggested that secretory IFTase in P. pastoris could be a viable method to resolve low extracellular IFTase activity both in the E. coli system and in the original strain. In fact, reports that Pichia high‐density fermentation can greatly improve recombinase activity are common . Moreover, the activity of lipase B (secreted from Pichia ) was reported to increase from 57.9 to 11 900 U mL −1 when its culture was upscaled from a flask to a 50 L fermenter .…”

“…Then the methanol feeding was started to induce the production of IFTase. After the induction of methanol for 60 h, the biomass OD 600 15,25,31 Moreover, the activity of lipase B (secreted from Pichia) was reported to increase from 57.9 to 11 900 U mL −1 when its culture was upscaled from a flask to a 50 L fermenter. 32 Therefore this system might be expected to achieve higher IFTase activity in larger-volume fermentation of industrial production.…”

Process optimization of high-level extracellular production of alkaline pectate lyase in recombinant Escherichia coli BL21 (DE3)

“…The product yields were detected by using a spectrophotometer (Shimadzu, UV-1800PC). One standard enzyme unit was defined as the yield of 1 mol unsaturated polygalacturonic acid per minute, with a molar extinction coefficient of 4600 L/(mol cm) [13,26].…”