초록
<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P><B>Effects of co‐substrate sorbitol different feeding strategies on recombinant human growth hormone (rhGH) production by <I>Pichia pastoris hGH</I>‐Mut<I><SUP>+</SUP></I> were investigated by eight designed experiments grouped as: (i) fed‐batch methanol feeding without the co‐substrate; (ii) fed‐batch methanol feeding with pulse sorbitol feeding; (iii) fed‐batch methanol feeding together with fed‐batch sorbitol feeding at <I>t</I> = 0–15 h, followed by fed‐batch methanol feeding; and (iv) fed‐batch methanol and sorbitol feeding at <I>t</I> = 0–30 h, followed with fed‐batch methanol feeding</B>.</P><P><B>RESULTS</B></P><P><B>The highest rhGH and cell concentrations were achieved, respectively, as 0.64 g L<SUP>−1</SUP> and 105 g L<SUP>−1</SUP> at <I>t</I> = 42 h of induction phase, with the strategy where methanol was fed to the system at a pre‐determined feeding rate of μ<SUB>M0</SUB>=0.03 h<SUP>−1</SUP>, and sorbitol concentration was kept at 50 g L<SUP>−1</SUP> at <I>t</I> = 0–15 h of the rhGH production phase where the specific growth rate on sorbitol was μ<SUB>S0</SUB>=0.025 h<SUP>−1</SUP>. The overall cell and product yield on total substrate were found as 0.26 g g<SUP>−1</SUP> and 2.26 mg g<SUP>−1</SUP>, respectively</B>.</P><P><B>CONCLUSION</B></P><P><B>This work demonstrates that co‐carbon source, sorbitol, feeding strategy is as important as methanol feeding strategy in recombinant protein production by Mut<SUP>+</SUP> strains of <I>P. pastoris</I>. © 2012 Society of Chemical Industry</B></P>