Example 3: Generation of improved succinate alanine strains
a) Basfia succiniciproducens DD1 was transformed as described above with the
pSacB_เดลต้า_/dhA and "Campbelled in" to yield a "Campbell in" strain. Transformation and integration into the genome of Basfia succiniciproducens was confirmed by PCR
20 yielding bands for the integrational event of the plasmid into the genome of Basfia
succiniciproducens.
The "Campbell in" strain was then "Campbelled out" using agar plates containing ซูโครส as a counter selection medium, selecting for the loss (of function) of the sacB gene. Therefore, the "Campbell in" strains were incubated in 25-35 ml of non selective
25 medium (BHI containing no antibiotic) at 37°C, 220 rpm over night. The overnight
culture was then streaked onto freshly prepared BHI containing ซูโครส plates (10%,
no antibiotics) and incubated overnight at 37°C ("first การส่งผ่านซูโครส"). Single colony
obtained from first transfer were again streaked onto freshly prepared BHI containing
ซูโครส plates (10%) and incubated overnight at 37°C ("second การส่งผ่านซูโครส").
30 This procedure was repeated until a minimal completion of five transfers ("third, forth,
fifth การส่งผ่านซูโครส") in ซูโครส. The term "first to fifth การส่งผ่านซูโครส" refers to the transfer of a strain after chromosomal integration of a vector containing a sacB-levan-
sucrase gene onto ซูโครส and growth medium containing agar plates for the purpose of selecting for strains with the loss of the sacB gene and the surrounding plasmid
35 sequences. Single colony from the fifth transfer plates were inoculated onto 25-35 ml
of non selective medium (BHI containing no antibiotic) and incubated at 37°C,
220 rpm over night. The overnight culture was serially diluted and plated onto BHI plates to obtain isolated single colonies.
The "Campbelled out" strains containing either the ไวด์ไทป์ situation of the /dhA-locus
40 or the mutation/deletion of the /dhA-gene were confirmed by คลอแรมเฟนิคอล
sensitivity. The mutation/deletion mutants among these strains were identified and
PF 75583
20
confirmed by PCR analysis. This led to the /dhA-deletion mutant Basfia succiniciproducens DD1 AldhA.
b) Basfia succiniciproducens DD1 AldhA was transformed with pSacB_เดลต้า_pf/D as
described above and "Campbelled in" to yield a "Campbell in" strain. Transformation
5 and integration was confirmed by PCR. The "Campbell in" strain was then
"Campbelled out" as described previously. The deletion mutants among these strains
were identified and confirmed by PCR analysis. This led to the IdhA OD-double
deletion mutant Basfia succiniciproducens DD1 AldhA Apf/D.
c) Basfia succiniciproducens DD1 AldhA ApfID (DD3) was transformed with pSacB_alaD
10 as described above and "Campbelled in" to yield a "Campbell in" strain.
Transformation and integration was confirmed by PCR. The "Campbell in" strain was then "Campbelled out" as described previously. The mutants among these strains were identified and confirmed by PCR analysis. This led to the IdhA pflD alaD mutant Basfia succiniciproducens DD1 AIdhA ApfID alaD (DD3 alaD).
15 d) Basfia succiniciproducens DD1 AldhA ApfID alaD (DD3 alaD) was transformed with
pSacB_เดลต้า_pckA as described above and "Campbelled in" to yield a "Campbell in" strain. Transformation and integration was confirmed by PCR. The "Campbell in" strain was then "Campbelled out" as described previously. The deletion mutants among these strains were identified and confirmed by PCR analysis. This led to the
20 mutant Basfia succiniciproducens DD1 AIdhA ApflD ApckA alaD (DD3 ApckA alaD).
Example 4: Cultivation of various DD1-strains on glucose
1. Medium preparation
25 The composition and preparation of the cultivation medium is as described in the
following tables 2 and 3.
Table 2a): Medium B4_AE (aerobic growth) composition (pre-culture) for cultivation on glucose.
Concentration
Compound
[g/L]
1 Calcium carbonate 50
2 Succinic acid 2.5
3 D-(+)-Glucose 50
4 Salt solution* 2,5
5 Sodium carbonate 2
6 Yeast extract 12.5
7 H2O ad 50 mL
30
PF 75583
21
Table 2 b) Medium B4_AN (anaerobic growth) composition (pre-culture) for cultivation on glucose.
Concentration
Compound
1 Magnesium sulfate
2 Succinic acid
3 D-(+)-Glucose
4 Salt solution*
5 Sodium carbonate
6 Yeast extract
7 H2O
* Salt solution:
[g/L]
50
2.5
50
2,5
2
12.5
ad 50 mL
Concentration
Compound
[gIL]
(NH4)2SO4 150
KH2PO4 100
5
Table 3a): Medium B5_AE (aerobic growth) composition glucose.
Concentration
(main-culture) for cultivation on
Compound
1 Calcium carbonate
2 Succinic acid
3 D-(+)-Glucose
4 Salt solution*
5 Ammonium sulfate
6 Sodium carbonate
7 Yeast extract
8 H2O
10
15
[g/L]
50
2.5
50
2,5
a) 6.5
b) 10.1
c) 13.7
2
12.5
ad 50 mL
PF 75583
22
Table 3b): Medium B5_AE (anaerobic growth) composition (main-culture) for cultivation on glucose.
Concentration
Compound
1 Magnesium sulfate
2 Succini