Effect of Nitrogen Source and Inorganic Phosphate Concentration on Methanol Utilization and PEX Genes Expression in Pichia pastoris

Figure 4

(a) Strains created in this study carry PHO5 reporter gene under control of different variants of AOX1 promoter: tr2-1-GS115 carries a native promoter, trΔSacI-1-GS115—a variant truncated in SacI site (−737), trΔNsiI-1-GS115—a variant truncated in NsiI site (−267), trA-1-GS115 carries AOX1 promoter with deletion from −296 to −216, trB-1-GS115 from −222 to −188, trC-1-GS115 from −205 to −45, and trD-1-GS115 from −80 to −0 nucleotides. (b) ACP specific activity of P. pastoris strains trA-1-GS115, trB-1-GS115, trC-1-GS115, trD-1-GS115, and tr2-1-GS115 in media with different nitrogen sources (MN with ammonium sulphate and MP with proline). (c) ACP specific activity of P. pastoris strains trΔSacI-1-GS115, trΔNsiI-1-GS115, andtr2-1-GS115 in media with different concentrations of KH₂PO₄ (MN with 1 g/L and in ML with 0,03 g/L).

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