Reduced phosphotransferase system activity in bacteria
A method of producing biological products using bacteria with an inactivated ptsHI and wild type err and no added glucose transport activity and which consumes nearly all glucose in the media is described. The ΔptsHI bacteria produce large quantities of recombinant protein without producing significant amounts of acetate. The bacteria grow well on standard LB broth without additional supplementation.
1. A method of producing recombinant protein comprising:
a) culturing an Escherichia coli bacteria under conditions to express a recombinant protein, and
b) isolating said recombinant protein,
wherein said bacteria has i) wild type crr (phosphoenolpyruvate sugar phosphotransferase system enzyme IIIGlc/IIGlcA); ii) inactivated ptsHI (phosphoenolpyruvate sugar phosphotransferase system enzyme I-enzyme HPr) and iii) no recombinant glucose transport activity added thereto, and wherein said bacteria accumulate less than 7.5 mm acetate during aerobic growth for at least 24 hours at 32° C. in a medium comprising 2% glucose.
2. The method of claim 1 , wherein said bacteria produces more than 7.5 fold more recombinant protein than the same strain without inactivated ptsHI.
3. The method of claim 1 , wherein said bacteria produces more than 25 fold more recombinant protein than the same strain without inactivated ptsHI.
4. The method of claim 1 , wherein said bacteria produces more than 100 fold more recombinant protein than the same strain without inactivated ptsHI.
5. The method of claim 1 , wherein said bacteria comprise a deletion of ptsH or ptsI or both.
6. The method of claim 1 , wherein said culture comprises LB broth with 10 g/L tryptone, 5 g/L yeast extract, 10 g/L NaCl.
7. The method of claim 1 , wherein said bacteria consume greater than 90% of the glucose present in the culture.
8. The method of claim 1 , wherein said the total amount of acetate accumulated is less than 7 mM.
9. The method of claim 1 , wherein said the total amount of acetate accumulated is less than 5 mM.
10. The method of claim 1 , wherein said the total amount of acetate accumulated is less than 3 mM.
11. The method of claim 1 , wherein said the total amount of acetate accumulated is less than 1 mM.
12. A recombinant bacteria having wild type non-PEP-PTS glucose transport activity, wild type crr and ΔptsHI.
13. A method of producing recombinant protein comprising:
a) culturing a bacteria under conditions to express a recombinant protein, and
b) isolating said recombinant protein,
wherein said bacteria is Escherichia coli and has wild type crr, ΔptsHI and no added recombinant glucose transport activity, and wherein said bacteria accumulate less than 10 mM acetate during aerobic growth for at least 24 hours at 32° C. in a medium comprising 2% glucose and produces more than 25 fold more recombinant protein than the same strain without ΔptsHI.