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LACTOBACILLUS-PLANTARUM LDHL GENE - OVEREXPRESSION AND DELETION
被引:86
作者:
FERAIN, T
[1
]
GARMYN, D
[1
]
BERNARD, N
[1
]
HOLS, P
[1
]
DELCOUR, J
[1
]
机构:
[1] UNIV CATHOLIQUE LOUVAIN, DEPT BIOL, GENET MOLEC LAB, UNITE GENET, B-1348 LOUVAIN, BELGIUM
关键词:
D O I:
10.1128/jb.176.3.596-601.1994
中图分类号:
Q93 [微生物学];
学科分类号:
071005 ;
100705 ;
摘要:
Lactobacillus plantarum is a lactic acid bacterium that converts pyruvate to L-(+)- and D-(-)-lactate with stereospecific enzymes designated L-(+)- and D-(-)-lactate dehydrogenase (LDH), respectively. A gene (designated ldhL) that encodes L-(+)-lactate dehydrogenase from L. plantarum DG301 was cloned by complementation in Escherichia coli. The nucleotide sequence of the ldhL gene predicted a protein of 320 amino acids closely related to that of Lactobacillus pentosus. A multicopy plasmid bearing the ldhL gene without modification of its expression signals was introduced in L. plantarum. L-LDH activity was increased up to 13-fold through this gene dosage effect. However, this change had hardly any effect on the production of L-(+)- and D-(-)-lactate. A stable chromosomal deletion in the ldhL gene was then constructed in L. plantarum by a two-step homologous recombination process. Inactivation of the gene resulted in the absence of L-LDH activity and in exclusive production of the D isomer of lactate. However, the global concentration of lactate in the culture supernatant remained unchanged.
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页码:596 / 601
页数:6
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