Isolation, identification and genetic organization of the ADI operon in Enterococcus faecium GR7

Kaur, Baljinder; Kaur, Rajinder

doi:10.1007/s13213-014-0981-1

Cited by 4 publications

(3 citation statements)

References 38 publications

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“…Such findings were used to explain the selective effect of the ecological niche on the type and pathway of BA biosynthesis by a given microorganism (Nannelli and others ). However, recent reports demonstrated the occurrence of ADI‐positive LAB of the genera Enterococcus (Kaur and Kaur ) and Weissella (Kaur and Kaur ) in dairy products. Although dairy LAB are not expected to produce putrescine directly from arginine via the ADI pathway, because they lack the ODC enzyme, they can contribute to the accumulation of putrescine in dairy products by supplying the precursor ornithine to ODC‐positive contaminants of enterobacteria and pseudomonads.…”

Section: Biosynthesis Pathways Of Basmentioning

confidence: 99%

Biogenic Amines in Dairy Products: Origin, Incidence, and Control Means

Benkerroum

2016

Comp Rev Food Sci Food Safe

204

175

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Biogenic amines (BAs) are toxic compounds produced by a number of microorganisms (bacteria, yeasts, and molds) as a result of the metabolism of some amino acid, usually decarboxylation reactions. BA-producing microorganisms are not necessarily pathogenic, such as lactic acid bacteria, which are, on the contrary, among the most beneficial microbiota to human beings and some of which even have probiotic properties. However, the incidence of BAs in dairy products and their possible implication in serious dairy-borne intoxications has long been overlooked. Consequently, the implementation of control measures to limit such an incidence has not been considered among the priorities of the food safety authorities. Nonetheless, there is a growing concern with regard to the presence of BAs in dairy products, because their toxicological status as toxins that may have serious acute and/or chronic adverse health effects is becoming increasingly evident and well-documented. The main BAs associated with dairy products are reviewed herein from the perspective of their incidence in these food products, and to draw the attention of readers to the shortage in data to perform pertinent risk assessment, which is considered to be a key action to provide efficient control means and to help decision makers issue appropriate legislative and regulatory measures.

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Section: Biosynthesis Pathways Of Basmentioning

confidence: 99%

Biogenic Amines in Dairy Products: Origin, Incidence, and Control Means

Benkerroum

2016

Comp Rev Food Sci Food Safe

204

175

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“…Each LAB strain was cultivated in 50 mL MRS broth at 37 • C for 24 h, and then this activated culture was centrifuged at 9500× g for 15 min (Beckman Avanti J-26S XP). The supernatant was sterilized using a 0.45 µm pore-size filter to obtain cell-free supernatant for further experiments [29]. The indicators were inoculated in 5 mL LB broth for 12 h at 37 • C, and these cultures were then diluted to maintain 1~5 × 10 8 CFU/mL with sterilized water.…”

Section: Lab Strains and Evaluation Of Antibacterial Activitymentioning

confidence: 99%

Bacteriocin from Lacticaseibacillus rhamnosus sp. A5: Isolation, Purification, Characterization, and Antibacterial Evaluation for Sustainable Food Processing

et al. 2022

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A new Lacticaseibacillus rhamnosus strain A5 was isolated from pickle soup and characterized for its probiotic suitability. Strain A5 was Gram-positive, catalase-negative, acid-producing, and exhibited potential antibacterial activity against Escherichia coli (inhibition zone 17.3 mm), Bacillus subtilis (inhibition zone 14.5 mm), Salmonella enterica (zone of inhibition 16.1 mm) and Staphylococcus aureus (zone of inhibition 14.2 mm) by performing investigations on the disc diffusion. The cell-free supernatant of newly isolated strain A5 retained its inhibition ability of the growth of test bacteria at pH 2.0 to 5.0, temperature 121 °C for 30 min and UV irradiation for 8 h. However, the inhibitory effects of cell-free supernatant disappeared when subjected to papain, trypsin, and pepsin enzymatic treatments. By eliminating the interferences of organic acid and hydrogen peroxide, the cell-free supernatant possessed antibacterial activity against two indicator bacteria (E. coli and B. subtilis) and showed high thermal tolerance. These results indicated that the antibacterial substances produced by strain A5 were proteinaceous in nature, namely bacteriocin. The antibacterial bacteriocins in the supernatant of the strain A5 culture were further purified by ammonium sulfate fractionation and gel filtration chromatography. The purified bacteriocins also showed a pronounced inhibitory effect against E. coli and B. subtilis. The approximated molecular weight of bacteriocins was less than 14 kDa after determining by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In conclusion, the newly isolated strain A5 and its bacteriocins could be potentially applied in food preservation to prevent the risk of foodborne illness.

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“…CK was first isolated from Enterococcus faecalis, where it catalyzes ATP production as part of the arginine dihydrolase fermentation pathway (3). The kinase gene has since been identified in various other species that derive energy from arginine degradation (4)(5)(6). CKs have also been purified from pathogens of medical interest such as Mycoplasma penetrans (7), Giardia lamblia (8), and Trichomonas vaginalis (9).…”

mentioning

confidence: 99%

Hyperthermophilic Carbamate Kinase Stability and Anabolic In Vitro Activity at Alkaline pH

Hennessy

Latter

Fazelinejad

et al. 2018

Appl Environ Microbiol

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Carbamate kinases catalyze the conversion of carbamate to carbamoyl phosphate, which is readily transformed into other compounds. Carbamate forms spontaneously from ammonia and carbon dioxide in aqueous solutions, so the kinases have potential for sequestrative utilization of the latter compounds. Here, we compare seven carbamate kinases from mesophilic, thermophilic, and hyperthermophilic sources. In addition to the known enzymes from and, the previously unreported enzymes from the hyperthermophiles and, the thermophiles and, and the mesophile were all expressed recombinantly, each in high yield. Only the clostridial enzyme did not show catalysis. In direct assays of carbamate kinase activity, the three hyperthermophilic enzymes display higher specific activities at elevated temperatures, greater stability, and remarkable substrate turnover at alkaline pH (9.9 to 11.4). and carbamate kinases were found to be the most active when the enzymes were tested at 80°C, and maintained activity over broad temperature and pH ranges. These robust thermococcal enzymes therefore represent ideal candidates for biotechnological applications involving aqueous ammonia solutions, since nonbuffered 0.0001 to 1.0 M solutions have pH values of approximately 9.8 to 11.8. As proof of concept, here we also show that carbamoyl phosphate produced by the kinase is efficiently converted to carbamoyl aspartate by aspartate transcarbamoylase from the same source organism. Using acetyl phosphate to simultaneously recycle the kinase cofactor ATP, at pH 9.9 carbamoyl aspartate is produced in high yield and directly from solutions of ammonia, carbon dioxide, and aspartate. Much of the nitrogen in animal wastes and used in fertilizers is commonly lost as ammonia in water runoff, from which it must be removed to prevent downstream pollution and evolution of nitrogenous greenhouse gases. Since carbamate kinases transform ammonia and carbon dioxide to carbamoyl phosphate via carbamate, and carbamoyl phosphate may be converted into other valuable compounds, the kinases provide a route for useful sequestration of ammonia, as well as of carbon dioxide, another greenhouse gas. At the same time, recycling the ammonia in chemical synthesis reduces the need for its energy-intensive production. However, robust catalysts are required for such biotransformations. Here we show that carbamate kinases from hyperthermophilic archaea display remarkable stability and high catalytic activity across broad ranges of pH and temperature, making them promising candidates for biotechnological applications. We also show that carbamoyl phosphate produced by the kinases may be efficiently used to produce carbamoyl aspartate.

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Isolation, identification and genetic organization of the ADI operon in Enterococcus faecium GR7

Cited by 4 publications

References 38 publications

Biogenic Amines in Dairy Products: Origin, Incidence, and Control Means

Biogenic Amines in Dairy Products: Origin, Incidence, and Control Means

Bacteriocin from Lacticaseibacillus rhamnosus sp. A5: Isolation, Purification, Characterization, and Antibacterial Evaluation for Sustainable Food Processing

Hyperthermophilic Carbamate Kinase Stability and Anabolic In Vitro Activity at Alkaline pH

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