Mutated lactococcus strain

Abstract

A mutant of Lactococcus lactis spp. lactis , which produces lactate at high volumetric and specific productivity as well as high amounts of lactate dehydrogenase, as well as the use of said strain, and a method for producing lactate, as well as the use of the lactate thus produced.

1 . A mutant of  Lactococcus lactis  spp.  lactis , which produces lactate at high volumetric productivity, which is at least twice that of the  Lactococcus lactis  spp.  lactis  19435, and produces lactate at specific productivity, which is at least 1.5 times that of the  Lactococcus lactis  spp.  lactis  19435, and produces high amounts of lactate dehydrogenase, which is at least twenty times that of the  Lactococcus lactis  spp.  lactis  19435.  
     
     
         2 . A mutant according to  claim 1 , denoted TMB5003, deposited at Deutsche Sammlung von Microorganismen und Zellkulturen under deposition number DSM 14489.  
     
     
         3 . The use of  Lactococcus lactis  spp.  lactis  TMB5003 in the production of lactate.  
     
     
         4 . The use of  Lactococcus lactis  spp.  lactis  TMB5003 for the production of the enzyme lactate dehydrogenase, LDH, in particular L-lactate dehydrogenase, L-LDH.  
     
     
         5 . A method for the production of lactate on a glucose containing medium, wherein an inoculum of  Lactococcus lactis  spp.  lactis  TMB5003 is grown on a medium comprising glucose as carbon source.  
     
     
         6 . A method according to  claim 5 , wherein the growth is carried at conditions optimized for production of L-lactate.  
     
     
         7 . A method according to  claim 6 , wherein the growth is continuous at a dilution rate of at least 0.5 h −1 .  
     
     
         8 . A method according to  claim 7 , wherein the growth is continuous at a dilution rate of at least 0.7 h −1 .  
     
     
         9 . A method according to  claim 8 , wherein the growth is continuous at a dilution rate of at least 0.8 h −1 .  
     
     
         10 . A method according to  claim 5 , wherein the growth is carried out at unrestricted feed of glucose.  
     
     
         11 . A method according to  claim 5 , wherein the growth is carried out at a pH of above 6, preferably pH 6-7.  
     
     
         12 . A method according to  claim 5 , wherein the growth is carried out at a temperature of between 25 and 30° C., preferably 27.5 to 30° C.  
     
     
         13 . The use of lactate produced by fermenting the mutant  Lactococcus lactis  spp.  lactis  TMB5003 in food and as a chemical commodity in general.