|
Stepwise improvement of PGA production and export using B. megaterium |
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| Strain |
Plasmid |
Medium* |
Cultivation |
PGA activity [U gCDW -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 mgprotein -1 [27]. Standard derivations performed experiments were below 10 %. | |||||
Yang et al. Microbial Cell Factories 2006 5:36 doi:10.1186/1475-2859-5-36 |
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