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 medicament comprising a bacterium selected from the group consisting of lactic acid bacteria and Bifidobacterium species lacking cellobiose-specific PTS system IIC component (PtcC) activity, wherein the bacterium overexpresses a gene encoding a trehalose transporter, and wherein a gene encoding endogenous TrePP has been partially or completely deleted, disrupted or inactivated.
2. The medicament of claim 1 , wherein the gene encoding endogenous PtcC has been partially or completely deleted, disrupted or inactivated.
3. The medicament of claim 2 , wherein the gene encoding endogenous PtcC is incapable of producing functional PtcC gene product.
4. The medicament according to claim 2 , wherein the PtcC gene encodes a PtcC gene product having an amino acid sequence which is at least 75% identical to SEQ ID NO: 8.
5. The medicament according to claim 1 , wherein the gene encoding endogenous TrePP is incapable of producing functional TrePP gene product.
6. The medicament according to claim 1 , wherein the trehalose transporter is endogenous.
7. The medicament according to claim 1 , wherein the bacterium comprises functional heterologous trehalose 6-phosphate phosphatase.
8. The medicament according to claim 7 , wherein said trehalose 6-phosphate phosphatase is otsB.
9. The medicament according to claim 8 , wherein the otsB is from E. coli.
10. The medicament according to claim 1 , wherein the bacterium comprises one or more heterologous gene product(s).
11. The medicament according to claim 10 , wherein the one or more heterologous gene product(s) are prophylactic and/or therapeutic gene product(s).
12. The medicament according to claim 1 , wherein the bacterium is dried, spray-dried, frozen or freeze-dried.
13. The medicament according to claim 1 , wherein the lactic acid bacteria is a Lactococcus sp. or a Lactobacillus sp.
14. The medicament according to claim 13 , wherein said Lactococcus sp. is Lactococcus lactis.