scholarly journals Short communication: Enzymatic perspective of galactosidases reveals variations in lactose metabolism among Lactococcus lactis strains

2019 ◽  
Vol 102 (7) ◽  
pp. 6027-6031 ◽  
Author(s):  
Yu Yang ◽  
Nan Li ◽  
Yang Jiang ◽  
Zhenmin Liu ◽  
Xiaoming Liu ◽  
...  
2020 ◽  
Vol 103 (1) ◽  
pp. 161-165 ◽  
Author(s):  
Zhi-Qiang Xiong ◽  
Yun-Ying Wei ◽  
Ling-Hui Kong ◽  
Xin Song ◽  
Hua-Xi Yi ◽  
...  

2013 ◽  
Vol 96 (6) ◽  
pp. 3558-3563 ◽  
Author(s):  
B. Turchi ◽  
M.L. Van Tassell ◽  
A. Lee ◽  
R. Nuvoloni ◽  
D. Cerri ◽  
...  

2014 ◽  
Vol 99 (1) ◽  
pp. 337-347 ◽  
Author(s):  
Tamara Aleksandrzak-Piekarczyk ◽  
Lidia Stasiak-Różańska ◽  
Jarosław Cieśla ◽  
Jacek Bardowski

1998 ◽  
Vol 64 (6) ◽  
pp. 2111-2116 ◽  
Author(s):  
S.-Q. Liu ◽  
R. V. Asmundson ◽  
P. K. Gopal ◽  
R. Holland ◽  
V. L. Crow

The influence of reduced water activity (aw) on lactose metabolism by Lactococcus lactis subsp.cremoris 2254 and 2272 was studied at different pH values. In control incubations (aw, 0.99) with nongrowing cells in pH-controlled phosphate buffer, the levels of carbon recovered asl-(+)-lactate were 92% at pH 6.1 and 5.3 and 78% at pH 4.5. However, the levels of recovery decreased to ∼50% at all pH values tested when the aw was 0.88 (with glycerol as the humectant). When growing cells in broth controlled at pH 6.3 were used, a reduction in the aw from 0.99 to 0.96 resulted in a decrease in the level of lactose carbon recovered asl-(+)-lactate from 100 to 71%. Low levels ofl-(+)-lactate carbon recovery (<50%) were also observed with cells resuspended in pH-uncontrolled reconstituted skim milk at aw values of 0.99 and 0.87 and in young cheese curds. The missing lactose carbon could not be accounted for by acetate, ethanol, formate, acetaldehyde, or pyruvate. Attempts were made to determine where the missing lactose carbon was diverted to under the stress conditions used. Some of the missing lactose carbon was recovered as galactose (0.1 to 2.5 mM) in culture supernatants. Decreasing either the aw or the pH resulted in increased galactose accumulation by nongrowing cells; adjusting both environmental factors together potentiated the effect. The sensitivities of the two lactococcal strains tested were different; strain 2272 was more prone to accumulate galactose under stress conditions. A methyl pentose(s) and additional galactose were found in acid-hydrolyzed supernatants from cultures containing both growing and nongrowing cells, indicating that a saccharide(s) rich in these components was formed by lactococci under low-aw and low-pH stress conditions.


2019 ◽  
Vol 102 (5) ◽  
pp. 3933-3938 ◽  
Author(s):  
Jike Lu ◽  
Lianming Cui ◽  
Songyang Lin ◽  
Limin Hao ◽  
Nana Cao ◽  
...  

2019 ◽  
Vol 102 (11) ◽  
pp. 9763-9766 ◽  
Author(s):  
E. Martins ◽  
D.C. Cnossen ◽  
C.R.J. Silva ◽  
M. Vakarelova ◽  
A.F. Carvalho

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