Cells with altered betaine catabolism and their use in producing metabolites or enzymes

Abstract

PCT No. PCT/FR93/01202 Sec. 371 Date May 18, 1995 Sec. 102(e) Date May 18, 1995 PCT Filed Dec. 7, 1993 PCT Pub. No. WO94/13813 PCT Pub. Date Jun. 23, 1994Cells with an alteration at least in the gene involved in betaine catabolism, their preparation and their use, in particular for producing metabolites and/or enzymes, are disclosed.

We claim:  
     
       1. A process for the production of metabolites or enzymes or both comprising 
       a) genetically modifying a cell by gene disruption, wherein said disruption causes at least one stable or nonreversible modification in a gene encoding a protein involved in the catabolism of glycine-betaine; and  
       b) culturing said cell under production conditions.  
     
     
       2. The process according to  claim 1 , wherein the modified cell degrades betaine less rapidly than an unmodified cell. 
     
     
       3. The process according to  claim 2 , wherein the modification affects the coding portion of said gene and/or  or the regions responsible for the expression and/or  or the transcriptional regulation of said gene. 
     
     
       4. The process according to  claim 2 , wherein the cell is of a genus selected from the group consisting of Pseudomonas, Streptomyces, Actinomycetes, Propionibacterium, Corynebacterium, Bacillus, Escherichia, Salmonella, Rhizobium, Agrobacterium, Rhodopseudomonas, Xanthomonas, Clostridium and Methanobacterium. 
     
     
       5. The process according to  claim 2 , wherein the metabolite is selected from the group consisting of 
       (a) amino acids,  
       (b) vitamins,  
       (c) antibiotics,  
       (d) a derivative of (a), (b) or (c), and  
       (e) a precursor of (a), (b) or (c).  
     
     
       6. The process according to  claim 5 , characterized in that the metabolite is vitamin B12. 
     
     
       7. The process according to  claim 1 , wherein the cell is of a genus selected from the group consisting of Pseudomonas, Streptomyces, Actinomycetes, Propionibacterium, Corynebacterium, Bacillus, Escherichia, Salmonella, Rhizobium, Agrobacterium, Rhodopseudomonas, Xanthomonas, Clostridium and Methanobacterium. 
     
     
       8. The process according to  claim 1 , wherein the metabolite is selected from the group consisting of 
       (a) amino acids,  
       (b) vitamins,  
       (c) antibiotics,  
       (d) a derivative of (a), (b) or (c), and  
       (e) a precursor of (a), (b) or (c).  
     
     
       9. The process according to  claim 8 , characterized in that the metabolite is a cobalamin. 
     
     
       10. The process according to  claim 8 , wherein the metabolite is vitamin B12. 
     
     
       11. The process according to  claim 1 , wherein said gene encodes an enzyme selected from the group consisting of betaine homocysteine methyltransferase, dimethylglycine dehydrogenase, and sarcosine dehydrogenase. 
     
     
       12. The process according to  claim 11 , wherein said enzyme is betaine homocysteine methyltransferase. 
     
     
       13. The process according to  claim 11 , wherein said enzyme is dimethylglycine dehydrogenase. 
     
     
       14. A process according to  claim 1 , wherein the step of gene disruption comprises insertion of a transposon. 
     
     
       15. A process according to  claim 1 , wherein the step of gene disruption comprises homologous recombination. 
     
     
       16. A recombinantly modified cell comprising at least one stable or nonreversible modification in a gene encoding a protein involved in the catabolism of glycine-betaine, wherein said modification is a gene disruption. 
     
     
       17. The recombinantly modified cell according to  claim 16 , wherein said gene encodes an enzyme selected from the group consisting of betaine homocysteine methyltransferase, dimethylglycine dehydrogenase, and sarcosine dehydrogenase. 
     
     
       18. The recombinantly modified cell according to  claim 17 , wherein said enzyme is betaine homocysteine methyltransferase. 
     
     
       19. The recombinantly modified cell according to  claim 17 , wherein said enzyme is dimethylglycine dehydrogenase. 
     
     
       20. A cell according to  claim 16 , wherein said gene disruption comprises an insertion. 
     
     
       21. A process for the production of metabolites or enzymes or both, comprising culturing the recombinantly modified cell according to  claim 16  under production conditions. 
     
     
       22. The process according to  claim 21 , wherein said gene encodes an enzyme selected from the group consisting of betaine homocysteine methyltransferase, dimethylglycine dehydrogenase, and sarcosine dehydrogenase. 
     
     
       23. The process according to  claim 22 , wherein said enzyme is betaine homocysteine methyltransferase. 
     
     
       24. The process according to  claim 22 , wherein said enzyme is dimethylglycine dehydrogenase. 
     
     
       25. The process according to  claim 21 , wherein said gene disruption comprises an insertion.