Kinetic of Carbon Dioxide Production by Leuconostoc mesenteroides Grown in Single and Mixed Culture with Lactococcus lactis in Skimmed Milk

10.5580/ed ◽  
2008 ◽  
Vol 5 (2) ◽  
Keyword(s):  
Carbon Dioxide ◽  
Mixed Culture ◽  
Lactococcus Lactis ◽  
Leuconostoc Mesenteroides ◽  
Carbon Dioxide Production ◽  
Skimmed Milk

scholarly journals Metabolism of lactose and citrate by mutants of Lactococcus lactis producing excess carbon dioxide

2000 ◽  
Vol 67 (4) ◽  
pp. 571-583 ◽  
Author(s):  
AISHA EL ATTAR ◽  
CHRISTOPHE MONNET ◽  
GEORGES CORRIEU
Keyword(s):  
Carbon Dioxide ◽  
Lactococcus Lactis ◽  
Parent Strain ◽  
High Performance ◽  
Carbon Dioxide Production ◽  
Lactate Dehydrogenase Activity ◽  
Excess Carbon ◽  
Gas Generators ◽  
The Stability ◽  
Spontaneous Mutants

Mutants of Lactococcus lactis producing excess carbon dioxide could be isolated on LDHA-20 agar (described by El Attar et al. Journal of Dairy Research67 641–646 2000). The use of these mutants in the manufacture of Roquefort cheese has the potential to improve the formation of openings in this cheese. The aim of this work was to examine the stability of these mutants, their enzymic activities and their metabolism of lactose and citrate during growth in milk. They produced less l-lactate than the parent strain and their lactate dehydrogenase activity was lower. Nevertheless none of the mutants produced no L-lactate at all and the most active gas generators among them generally produced 30–50 mM-L-lactate. Unexpectedly, all the strains produced some D-lactate, some > 10 mM. We found that carbon dioxide production by the mutants could be determined indirectly by assaying acetoin, citrate and 2,3-butanediol by high-performance liquid chromatography. Generally, spontaneous mutants were more stable than those obtained after treating with nitrosoguanidine or u.v. irradiation.

Metabolism during normoxia, hyperoxia, and recovery in newborn rats

1992 ◽  
Vol 70 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Peter B. Frappell ◽  
Andrea Dotta ◽  
Jacopo P. Mortola
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Carbon Dioxide Production ◽  
Oxygen Availability ◽  
Aerobic Metabolism ◽  
Newborn Rats ◽  
Ambient Temperatures ◽  
Positive Effects

Aerobic metabolism (oxygen consumption, [Formula: see text], and carbon dioxide production, [Formula: see text]) has been measured in newborn rats at 2 days of age during normoxia, 30 min of hyperoxia (100% O2) and an additional 30 min of recovery in normoxia at ambient temperatures of 35 °C (thermoneutrality) or 30 °C. In normoxia, at 30 °C [Formula: see text] was higher than at 35 °C. With hyperoxia, [Formula: see text] increased in all cases, but more so at 30 °C (+20%) than at 35 °C (+9%). Upon return to normoxia, metabolism readily returned to the prehyperoxic value. The results support the concept that the normoxic metabolic rate of the newborn can be limited by the availability of oxygen. At temperatures below thermoneutrality the higher metabolic needs aggravate the limitation in oxygen availability, and the positive effects of hyperoxia on [Formula: see text] are therefore more apparent.Key words: neonatal respiration, oxygen consumption, thermoregulation.

Sign in / Sign up

Export Citation Format

Share Document