Impact of NH4+ nitrogen source on the production of Rhizopus oryzae lipase in Pichia pastoris

Towards optimal substrate feeding for heterologous protein production in Pichia pastoris (Komagataella spp) fed‐batch processes under PAOX1 control: a modeling aided approach

“…The nitrogen needs were fulfilled by the addition of NH 4 Cl solution (200 g of NH 4 Cl, 5 mL of trace salts solution and 2 mL of biotin solution per liter). Its flow rate was directly linked to the methanol flow rate and automatically calculated online by the previously estimated ammonium chloride/methanol requirements: 0.12 g g −1 to maintain the suitable NH 4 + concentration …”

“…Its flow rate was directly linked to the methanol flow rate and automatically calculated online by the previously estimated ammonium chloride/methanol requirements: 0.12 g g −1 to maintain the suitable NH 4 + concentration. 41,42 The DO was controlled at 25% with respect to the air saturation (∼2.3 × 10 −4 mol O 2 L −1 ) by a cascade-based control, which involved regulating the stirring rate between 800 and 1000 rpm wileyonlinelibrary.com/jctb and the total inlet gas flow rate of air and additional pure oxygen, within the range 1-2 vvm. The temperature was kept at a value of 30 ∘ C and the pH at 5.5, throughout the three phases of the process.…”

NITROGEN SOURCES ON TPOMW VALORIZATION THROUGH SOLID STATE FERMENTATION PERFORMED BY Yarrowia lipolytica

“…The highest lipase activity was obtained at a concentration of 440 mmol after 52 hours, with an increase of 71% considering the control system. The presence of NH 4 + in the broth also prevented protease production (Yu et al, 2013), a fact that can explain the higher maintenance of lipase production all along the fermentation with this nitrogen source.…”

“…Ammonia for example can be used not only as nitrogen source, but also as pH regulator during the induction stage. The ammonium ion released into the fermentation broth has a deep impact on cell growth, expression and degradation of foreign protein (Yu et al, 2013). Yeast extract and hydrolyzed casein are usually great nitrogen sources for lipase stimulation (Fickers et al, 2004;Moftah et al, 2012;Veerabhadrappa et al, 2013).…”

Development of a New High-Cell Density Fermentation Strategy for Enhanced Production of a Fungus β-Glucosidase in Pichia pastoris

“…Normally, under sole methanol induction the majorities of reductive power NADH for ATP regeneration are originated from dissimilation pathway. TCA cycle also generates NADH, but under methylotrophic metabolism environment this pathway is not essential for energizing proteins but mainly serves for biosynthetic purpose (Yu et al, 2013). Methanol not only is the inducer of AOX1 promotor and the only carbon source for production, but also the yeast is sensitive to methanol concentration.…”