Citrate metabolism by Enterococcus faecium and Enterococcus durans isolated from goat’s and ewe’s milk: influence of glucose and lactose

2007 ◽  
Vol 53 (5) ◽  
pp. 607-615 ◽  
Author(s):  
María E. Cabral ◽  
María C. Abeijón Mukdsi ◽  
Roxana B. Medina de Figueroa ◽  
Silvia N. González
Keyword(s):  
Energy Source ◽  
Enterococcus Faecium ◽  
Specific Activity ◽  
Acetolactate Synthase ◽  
Acetate Kinase ◽  
Enterococcus Durans ◽  
Flavour Compounds ◽  
Citrate Metabolism ◽  
Citrate Lyase ◽  
Sole Energy

Citrate metabolism by Enterococcus faecium ET C9 and Enterococcus durans Ov 421 was studied as sole energy source and in presence of glucose or lactose. Both strains utilized citrate as the sole energy source. Enterococcus faecium ET C9 showed diauxic growth in the presence of a limiting concentration of glucose. Neither strain used citrate until glucose was fully metabolized. The strains showed co-metabolism of citrate and lactose. Lactate, acetate, formate, and flavour compounds (diacetyl, acetoin, and 2,3-butanediol) were detected in both strains. The highest production of flavour compounds was detected during growth of E. durans Ov 421 in media supplemented with citrate–glucose and citrate–lactose. Citrate lyase was inducible in both strains. Acetate kinase activities presented the highest values in LAPTc medium, with E. faecium ET C9 displaying a specific activity 2.4-fold higher than E. durans. The highest levels of α-acetolactate synthase specific activity were detected in E. durans grown in LAPTc+g, in accordance with the maximum production of flavour compounds detected in this medium. Diacetyl and acetoinreductases displayed lower specific activity values in the presence of citrate. Enterococcus faecium and E. durans displayed citrate lyase, acetate kinase, α-acetolactate synthase, and diacetyl and acetoin reductase activities. These enzymes are necessary for conversion of citrate to flavour compounds that are important in fermented dairy products.

Constitutive nature of the enzymes of citrate metabolism inStreptococcus lactissubsp.diacetylactis

1981 ◽  
Vol 48 (3) ◽  
pp. 489-495 ◽  
Author(s):  
Timothy M. Cogan
Keyword(s):  
Acetolactate Synthase ◽  
Streptococcus Lactis ◽  
Citrate Metabolism ◽  
Citrate Lyase ◽  
In Cells

SummaryFour enzymes of citrate metabolism (viz. citrate lyase, acetolactate synthase, diacetyl reductase and acetoin reductase) were constitutively present in cells of several strains ofStreptococcus lactissubsp.diacetylactis. In strain DRC1, which was studied in detail, diacetyl reductase and acetoin reductase were partly repressed and acetolactate synthase partly induced by growth on citrate. The stage of growth also affected the formation of each enzyme. The buffer species affected the activity of acetolactate synthase, diacetyl reductase and acetoin reductase.

scholarly journals Cometabolism of Citrate and Glucose by Enterococcus faecium FAIR-E 198 in the Absence of Cellular Growth

2006 ◽  
Vol 72 (1) ◽  
pp. 319-326 ◽  
Author(s):  
Frederik Vaningelgem ◽  
Veerle Ghijsels ◽  
Effie Tsakalidou ◽  
Luc De Vuyst
Keyword(s):  
Carbon Dioxide ◽  
Energy Source ◽  
Enterococcus Faecium ◽  
Cellular Growth ◽  
Citrate Metabolism ◽  
Constant Ph ◽  
End Products ◽  
Feta Cheese ◽  
Ph Conditions ◽  
Ph Range

ABSTRACT Citrate metabolism by Enterococcus faecium FAIR-E 198, an isolate from Greek Feta cheese, was studied in modified MRS (mMRS) medium under different pH conditions and glucose and citrate concentrations. In the absence of glucose, this strain was able to metabolize citrate in a pH range from constant pH 5.0 to 7.0. At a constant pH 8.0, no citrate was metabolized, although growth took place. The main end products of citrate metabolism were acetate, formate, acetoin, and carbon dioxide, whereas ethanol and diacetyl were present in smaller amounts. In the presence of glucose, citrate was cometabolized, but it did not contribute to growth. Also, more acetate and less acetoin were formed compared to growth in mMRS medium and in the absence of glucose. Most of the citrate was consumed during the stationary phase, indicating that energy generated by citrate metabolism was used for maintenance. Experiments with cell-free fermented mMRS medium indicated that E. faecium FAIR-E 198 was able to metabolize another energy source present in the medium.

Induction of some enzymes of citrate metabolism inLeuconostoc lactisand other heterofermentative lactic acid bacteria

1981 ◽  
Vol 48 (3) ◽  
pp. 497-502 ◽  
Author(s):  
Dervla Mellerick ◽  
Timothy M. Cogan
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acetolactate Synthase ◽  
Citrate Metabolism ◽  
Citrate Lyase ◽  
Leuconostoc Lactis

SummaryCitrate stimulated growth, totally induced citrate lyase, partly induced acetolactate synthase activity and partly repressed both diacetyl and acetoin reductases inLeuconostoc lactisNCW1. Similar results were obtained with 2 other leuconostocs and a heterofermentative lactobacillus. In 2 of the 3 leuconostocs tested, diacetyl reductase and acetoin reductase were NADPH specific, while in the 2 heterofermentative lactobacilli, they were NADH specific.

Chlorsulfuron Tolerance and Acetolactate Synthase Activity in Corn (Zea maysL.) Inbred Lines

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 553-557 ◽  
Author(s):  
Giuseppe Forlani ◽  
Erik Nielsen ◽  
Pierangelo Landi ◽  
Roberto Tuberosa
Keyword(s):  
Callus Tissue ◽  
Specific Activity ◽  
Acetolactate Synthase ◽  
Inbred Lines ◽  
Root Tips ◽  
Stages Of Growth ◽  
Naturally Occurring ◽  
Tolerant Line ◽  
Corn Inbred

Seven corn inbred lines previously shown to differ in response to soil residues of chlorsulfuron were characterized as to the target-enzyme acetolactate synthase (ALS) specific activity and to its susceptibility to the herbicide. ALS from plantlets at the five-leaf stage of growth was similarly susceptible to chlorsulfuron in all lines and its specific activity in the shoots was not significantly correlated with in vivo tolerance to the herbicide. By contrast, differences in ALS specific activity in roots of plants both at the five- and three-leaf stages of growth were significantly correlated (r = 0.96∗∗and r = 0.93∗∗, respectively) with in vivo tolerance. Correlation was also noted in extracts from cultured excised root tips (r = 0.94∗∗). Callus tissue of a chlorsulfuron-tolerant line was less affected by the herbicide and had a significantly higher ALS specific activity than callus from a chlorsulfuron susceptible line, whereas inhibition of ALS by the herbicide was similar in both lines. These results indicate that the naturally occurring differences in ALS levels in the roots of the investigated inbred lines contribute largely to the differential in vivo response observed to chlorsulfuron.

Effect of valine and the herbicide sulfometuron methyl on acetolactate synthase activity in nuclear and plasmid-borne sulphometuron methyl resistant Saccharomyces cerevisiae strains

1988 ◽  
Vol 34 (5) ◽  
pp. 680-685 ◽  
Author(s):  
S. N. Maiti ◽  
M. W. Zink ◽  
G. H. Rank
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Copy Number ◽  
Specific Activity ◽  
Feedback Inhibition ◽  
Acetolactate Synthase ◽  
Wild Type ◽  
Sulfometuron Methyl ◽  
Isogenic Lines

Acetolactate synthase (ALS) specific activity was evaluated in isogenic lines of Saccharomyces cerevisiae carrying the wild-type ILV2 gene or mutations in this gene for resistance to the herbicide sulfometuron methyl (SM). Statistical comparisons were made between two nuclear alleles and among five alleles borne on a YE chimaeric plasmid transformed into a strain carrying a 1.5-kilobase deletion in the nuclear ILV2 gene. Decreased ALS activity of plasmid-borne SM-resistant mutations was shown not to be caused by copy number effects. ALS-specific activity in strains carrying the wild-type ILV2 allele exhibited strong feedback inhibition by valine and was sensitive to SM. All nuclear and plasmid-borne SM-resistance alleles resulted in ALS-specific activity highly resistant to SM and resistant to valine feedback inhibition.

scholarly journals Enterococcus faecium and Enterococcus durans isolated from cheese: Survival in the presence of medications under simulated gastrointestinal conditions and adhesion properties

2017 ◽  
Vol 100 (2) ◽  
pp. 933-949 ◽  
Author(s):  
Daniel M.F. Amaral ◽  
Luana F. Silva ◽  
Sabrina N. Casarotti ◽  
Liane Caroline Sousa Nascimento ◽  
Ana Lúcia B. Penna
Keyword(s):  
Enterococcus Faecium ◽  
Adhesion Properties ◽  
Enterococcus Durans ◽  
Gastrointestinal Conditions

scholarly journals A biochemical explanation for the fatty liver and kidney syndrome of broilers: its alleviation by the short-term use of dietary fat

1977 ◽  
Vol 38 (3) ◽  
pp. 319-328 ◽  
Author(s):  
D. Balnave ◽  
R. B. Cumming ◽  
T. M. Sutherland
Keyword(s):  
Fatty Liver ◽  
Broiler Chickens ◽  
Specific Activity ◽  
Liver Lipid ◽  
Liver Weight ◽  
Atp Citrate Lyase ◽  
Commercial Diet ◽  
Meat Meal ◽  
Citrate Lyase ◽  
Liver And Kidney

1. Fatty liver and kidney syndrome (FLKS) was induced in young broiler chickens by giving them a diet composed principally of wheat and meat meal.2. FLKS resulted in reduced growth and increased liver weight; fasting for 18 h increased mortality, liver lipid and the specific activity of hepatic ATP-citrate lyase compared with birds fed on a commercial diet. The specific activities of hepatic fructose-l,6-diphosphate-l-phosphohydrolase and pyruvate carboxylase were reduced in birds suffering from FLKS and fasted for 18 h.3. Feeding of the FLKS-inducing diet supplemented with 150 g animal tallow/kg for 54 h considerably reduced mortality while restoring liver composition and enzyme activities towards those observed in birds fed a commercial diet. Investigations indicated that the glycerol component of the fat was not responsible for the observed responses.4. The present results suggest that in FLKS insufficiencies of biotin are induced in specific enzyme systems, but the syndrome may be alleviated without the use of supplementary biotin.5. The evidence indicates that, when stressed, birds affected by FLKS die from the hypoglycaemia occurring as a result of a reduced capacity for gluconeogenesis.

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