Heterologous expression of leader-less pga gene in Pichia pastoris: intracellular production of prokaryotic enzyme

Table 1 The effect of the transient phase profile on parameters of the fed-batch culture of P. pastoris X-33(pPIC-PA1) in a 10-l stirred bioreactor

TP profile - Experiment	Methanol	Maximal volumetric activity (h)*	Specific activity	Cell dry weight	Average volumetric activity	Average cell dry weight	Induction time	Specific productivity
	(%)	(U l^-1) (h)	(U g_cdw^-1)	(g l ^-1)	(U l^-1)	(g l ^-1)	(h)	(U g_cdw^-1 h^-1)
I - A	0.5	18000 (102)	163	120	16000	120	79	1.68
I - B	1.5	28100 (140)	258	109	25900	106	73	3.34
II - C	1.5	21500 (140)	182	115	20510	115	63	2.8
II - D	0.5	22420 (170)	167	130	20400	124	100	1.64

TP profile - transient phase profile: I - linear feeding of methanol, linear decrease of glycerol feeding, II - starvation for glycerol; methanol supplemented at the end of the transient phase in a single dose. Methanol - final concentration at the beginning of methanol feeding phase. * (h) means the hour at which maximal volumetric activity was achieved. Average volumetric activity - volumetric activity calculated from the last three values of activity assay. Induction time - time of growth on methanol required to achieve the average activity.

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