Modified gram positive bacteria and uses thereof
The present invention relates to gram positive bacteria with increased stress resistance and/or improved storage characteristics. In particular, the invention relates to gram positive bacterium which accumulate intracellular trehalose. The gram positive bacterium according to the invention lack cellobiose-specific PTS system IIC component (PtcC) activity. The gram positive bacterium may further lack trehalose 6-phosphate phosphorylase (TrePP) activity. The gram positive bacterium may further overexpress trehalose transporters. The invention further relates to compositions comprising such gram positive bacterium as well as methods and uses thereof.
1. A lactic acid bacterium (LAB) or Bifidobacterium , each lacking cellobiose-specific PTS system IIC component (PtcC) activity, wherein a gene encoding an endogenous PtcC of said LAB or said Bifidobacterium has been partially or completely deleted, disrupted, or inactivated so as to be incapable of producing a functional ptcC gene product, and wherein said LAB or said Bifidobacterium is genetically engineered to overexpress a gene encoding a trehalose transporter.
2. The LAB or Bifidobacterium according to claim 1 , wherein the ptcC gene or gene product has a nucleic acid or an amino acid sequence respectively at least 75% identical to SEQ ID NO: 7 or 8, respectively.
3. The LAB or Bifidobacterium according to claim 1 , each lacking trehalose 6-phosphate phosphorylase (TrePP) activity.
4. The LAB or Bifidobacterium according to claim 1 , each containing a functional, heterologous trehalose 6-phosphate phosphatase.
5. The LAB or Bifidobacterium according to claim 4 , wherein said trehalose 6-phosphate phosphatase is expressed from otsB.
6. The LAB or Bifidobacterium according to claim 1 , each containing a heterologous gene product.
7. The LAB or Bifidobacterium according to claim 1 , wherein said LAB or said Bifidobacterium is dried, spray-dried, frozen, or freeze-dried.
8. The LAB or Bifidobacterium according to claim 3 , wherein a gene encoding endogenous TrePP of said LAB or said Bifidobacterium has been partially or completely deleted, disrupted, or inactivated so as to be incapable of producing a functional trePP gene product.
9. The LAB or Bifidobacterium according to claim 1 , wherein the gene encoding the trehalose transporter is an endogenous trehalose transporter gene.
10. The LAB or Bifidobacterium according to claim 5 , wherein said otsB is from E. coli.
11. The LAB or Bifidobacterium according to claim 6 , wherein the heterologous gene product is a prophylactic and/or therapeutic gene product.
12. The LAB or Bifidobacterium according to claim 1 , wherein said LAB is a Lactococcus sp. or a Lactobacillus sp.
13. The LAB or Bifidobacterium according to claim 12 , wherein said LAB is a Lactococcus lactis.
14. The LAB or Bifidobacterium according to claim 1 , wherein the ptcC gene or gene product has a nucleic acid or an amino acid sequence respectively at least 80% identical to SEQ ID NO: 7 or 8, respectively.
15. The LAB or Bifidobacterium according to claim 1 , wherein the ptcC gene or gene product has a nucleic acid or an amino acid sequence respectively at least 85% identical to SEQ ID NO: 7 or 8, respectively.
16. The LAB or Bifidobacterium according to claim 1 , wherein the ptcC gene or gene product has a nucleic acid or an amino acid sequence respectively at least 90% identical to SEQ ID NO: 7 or 8, respectively.
17. The LAB or Bifidobacterium according to claim 1 , wherein the ptcC gene or gene product has a nucleic acid or an amino acid sequence respectively at least 95% identical to SEQ ID NO: 7 or 8, respectively.
18. The LAB or Bifidobacterium according to any one of claims 1 - 3 , 4 - 7 , and 8 - 17 , wherein said gene encoding said endogenous PtcC of said LAB or said Bifidobacterium is genetically engineered to be partially or completely deleted, disrupted, or inactivated.