High yield recombinant penicillin G amidase production and export into the growth medium using Bacillus megaterium

Table 2 Stepwise improvement of PGA production and export using B. megaterium

Strain	Plasmid	Medium*	Cultivation	PGA activity [U g_CDW ^-1]	PGA [mg L^-1]
MS941	pRBBm23	A5	SF	6.0	0.3
MS941	pRBBm23	A5	Batch	17.0	4.2
MS941	pRBBm23	LB1	SF	230.0	25.0
MS941	pRBBm49	LB1	SF	380.0	36.0
MS941	pRBBm49	LB2	SF	500.0	20.0
YYBm1	pRBBm23	LB1	SF	280.0	33.0
YYBm1	pRBBm49	LB1	SF	390.0	41.0
YYBm1	pRBBm49	LB2	SF	830.0	22.0
YYBm1	pRBBm49	MM	SF	0.0	0.0
YYBm1	pRBBm49	MM + 0.5 × AA	SF	170.0	11.0
YYBm1	pRBBm49	MM + 1 × AA	SF	330.0	35.0
YYBm1	pRBBm49	MM + 2 × AA	SF	200.0	28.0
YYBm1	pRBBm49	LB2	Batch	640.0	25.0
YYBm1	pRBBm49	MM + 1 × AA	Batch	320.0	29.0

*all media were supplemented with 2.5 mM CaCl
LB1 includes tryptone from Oxoid
LB2 was prepared with tryptone from Bacto
AA: amino acid solution
MM: MOPSO based minimal medium
SF: shaking flask cultivation.
Batch: pH controlled fermentation.
pRBBm23: B. megaterium pga gene encoding its natural leader sequence.
pRBBm49: B. megaterium pga gene encoding the LipA leader sequence.
The purified enzyme has a specific activity of 45 U mg_protein ^-1 [27]. Standard derivations performed experiments were below 10 %.

ISSN: 1475-2859