- G
- FDG
- FDGFD
- G
- FG
- G
Increasesr the ratio of the Air/O2 mixture.
A use the ratio of the mixture of O2/N2.
Controls methanol de feeding.
However, the dissolved oxygen ideonee concentration in the culture medium can range from 20% to 30% \cite{calzada,GAO_2013}.
Effets of indution temperature
The effect of temperature on cell growth and the production of recombinant proteins on the endoplasmic reticulum of yeast, can be very important, because if very high temperatures are used, folding can occur incorrectly, causing the degradation of the same and hence the stress of the strain, facts that would cause a metabolic overload in it, so the use of optimal temperature is very important, because the feeding of the substrate during the growth of the strain and methanol induction phases is 30°C, the metabolic stress of P. Pastoris and the formation of toxic products decrease significantly, causing cell growth and the production of recombinant proteins to increase \cite{calzada}. On the other hand, some research has reported that reducing the induction temperature of methanol from 30°C to 20°C is beneficial for the production of recombinant proteins, because at lower induction temperature, activation of alcohol oxidase (AOX) would increase the oxygen uptake rate (OUR), alleviating cell skeleton lysis and the secretion of protease , proteolytically reducing extracellular activity, however, doing this temperature drop and increasing OUR could be an inconvenience in the industry, as this increase would be a problem in terms of energy and as a result economic losses \cite{GAO_2013}.
Different studies have shown that the growth temperature of Pichia pastoris is 28 - 30°C for liquid cultures, plates, and slants. Growth above 32°C during induction can be detrimental to protein expression and can even lead to cell death \cite{invitrogen2010}.
Effects of pH
The P. Pastoris strain has a wide pH range to which they can be used, these can range from a pH range of 3.0 to 7.0, however, the optimal pH for strain and methanol growth as an inducer for the production of heterologous proteins is approximately 3.5 and 5.5, depending on the nature of the recombinant protein, for this, the pH has to be adjusted during the growth of the strain to a pH of 5.0 and this has to be adjusted again to a pH of 4.5 to introduce the methanol \cite{calzada,GAO_2013}.
Effects of nitrogen concentration
Nitrogen concentration is generally used to control the pH of the crop and for this, Yang and his co-authors in 2004 determined that the production of recombinant huridine by ammonium hydroxide (NH4OH) was obtained at a concentration of 0.4 M \cite{calzada,Yang_2004}.