Isolation and Purification of Enterocin EL1, a Bacteriocin Produced by a Strain of Enterococcus faecium†

1995 ◽  
Vol 58 (8) ◽  
pp. 890-898 ◽  
Author(s):  
WANDA J. LYON ◽  
DENNIS G. OLSON ◽  
ELSA A. MURANO

A meat isolate, identified as Enterococcus faecium L1, was found to produce a bacteriocin designated enterocin EL1 Enterocin EL1 was active against a narrow spectrum of microorganisms, inhibiting all tested strains of Listeria. Identification of the producer strain was determined phenotypically by biochemical and morphological tests. Enterocin EL1 was heat stable, sensitive to several proteolytic enzymes, and stable from pH 2 to 11. Adsorption of the bacteriocin to producer cells was dependent on ionic interaction of the bacteriocin and the cell surface at various pHs. By changing the pH of the extraction buffer, enterocin EL1 was extracted from E. faecium L1 cells in a concentrated form. Enterocin EL1 isolated by cell extraction was resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a protein with an approximate molecular weight of 2,300. Partially purified enterocin EL1 added to sensitive cells of Listeria ivanovii was bactericidal; however, the bacteriocin did not inhibit the producer strain L1.

2011 ◽  
Vol 57 (12) ◽  
pp. 993-1001 ◽  
Author(s):  
R. Satish Kumar ◽  
P. Kanmani ◽  
N. Yuvaraj ◽  
K.A. Paari ◽  
V. Pattukumar ◽  
...  

A bacteriocin producer strain MC13 was isolated from the gut of Mugil cephalus (grey mullet) and identified as Enterococcus faecium . The bacteriocin of E. faecium MC13 was purified to homogeneity, as confirmed by Tricine sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS–PAGE). Reverse-phase high-performance liquid chromatography (HPLC) analysis showed a single active fraction eluted at 26 min, and matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry analysis showed the molecular mass to be 2.148 kDa. The clear zone in native PAGE corresponding to enterocin MC13 band further substantiated its molecular mass. A dialyzed sample (semicrude preparation) of enterocin MC13 was broad spectrum in its action and inhibited important seafood-borne pathogens: Listeria monocytogenes , Vibrio parahaemolyticus , and Vibrio vulnificus . This antibacterial substance was sensitive to proteolytic enzymes: trypsin, protease, and chymotrypsin but insensitive to catalase and lipase, confirming that inhibition was due to the proteinaceous molecule, i.e., bacteriocin, and not due to hydrogen peroxide. Enterocin MC13 tolerated heat treatment (up to 90 °C for 20 min). Enterococcus faecium MC13 was effective in bile salt tolerance, acid tolerance, and adhesion to the HT-29 cell line. These properties reveal the potential of E. faecium MC13 to be a probiotic bacterium. Enterococcus faecium MC13 could be used as potential fish probiotic against pathogens such as V. parahaemolyticus, Vibrio harveyi , and Aeromonas hydrophila in fisheries. Also, this could be a valuable seafood biopreservative against L. monocytogenes.


2003 ◽  
Vol 69 (10) ◽  
pp. 5746-5753 ◽  
Author(s):  
Yukio Yamamoto ◽  
Yoshikazu Togawa ◽  
Makoto Shimosaka ◽  
Mitsuo Okazaki

ABSTRACT Lactic acid bacteria exhibiting activity against the gram-positive bacterium Bacillus subtilis were isolated from rice bran. One of the isolates, identified as Enterococcus faecalis RJ-11, exhibited a wide spectrum of growth inhibition with various gram-positive bacteria. A bacteriocin purified from culture fluid, designated enterocin RJ-11, was heat stable and was not sensitive to acid and alkaline conditions, but it was sensitive to several proteolytic enzymes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that enterocin RJ-11 had a molecular weight of 5,000 in its monomeric form. The amino acid sequence determined for purified enterocin RJ-11 exhibited high levels of similarity to the sequences of enterocins produced by Enterococcus faecium.


1997 ◽  
Vol 60 (12) ◽  
pp. 1520-1528 ◽  
Author(s):  
WANDA J. LYON ◽  
DENNIS G. OLSON

A swine fecal isolate, identified as Escherichia coli ECL12, was found to produce an antimicrobial substance designated as colicin ECL12. Colicin ECL12 was inhibitory against 20 strains of E. coli O157:H7 previously isolated from both human and bovine feces. Identification of the producer strain was determined phenotypically by biochemical and morphological tests. Colicin ECL12 was sensitive to several proteolytic enzymes. Adsorption of colicin ECL12 to sensitive cells of E. coli O157:H7 was bactericidal, resulting in a 2 log reduction in viable cell counts. Colicin ECL12 was purified from strain ECL12 by cell extraction and ion-exchange chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of colicin ECL12 resolved a single protein with a molecular weight of approximately 65,000.


2016 ◽  
Vol 13 (1) ◽  
pp. 133-145
Author(s):  
Baghdad Science Journal

In this paper to isolate and study the properties of the cyclooxygenase-2 (EC: 1.14.99.1) enzyme in the blood of a patient suffering from rheumatoid arthritis and study the effect of natural products of the Soapwort on the activity of purified enzyme. The study involves taking 30 ml of blood from an adult woman 40 years old, who suffers from rheumatoid arthritis disease for 13 years. Serum is separated and subjected to a series of purification processes including: precipitation by ammonium sulfate, filtration by centrifugation radiator, dialysis in presence of ammonium bicarbonate, separation using the technology of ion exchange, lipholization and then estimating approximate molecular weight of the enzyme using gel filtration technique and sodium dodecyl sulfate (SDS)-page polyacrylamide gel electrophoresis. The study also includes isolating the natural products of Soapwort plant and study the effect of isolated natural products on the activity of the purified enzyme. The result of the study indicates that cycloxygenase-2 has an approximate molecular weight of 71.5 kDa and that the extracted oil of the Soapwort has a negative impact on the activity of the enzyme (r= -0.824; P=0.006), while flavonoids and Saponin have no such impact (r= -0.565; P=0.113; r= -0.634; P=0.067 respectively).


2007 ◽  
Vol 73 (7) ◽  
pp. 2247-2250 ◽  
Author(s):  
Sirinat Srionnual ◽  
Fujitoshi Yanagida ◽  
Li-Hsiu Lin ◽  
Kuang-Nan Hsiao ◽  
Yi-sheng Chen

ABSTRACT Weissella cibaria 110, isolated from the Thai fermented fish product plaa-som, was found to produce a bacteriocin active against some gram-positive bacteria. Bacteriocin activity was not eliminated by exposure to high temperatures or catalase but was destroyed by exposure to the proteolytic enzymes proteinase K and trypsin. The bacteriocin from W. cibaria 110 was purified, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the purified bacteriocin contained one protein band that was approximately 2.5 kDa in size. Mass spectrometry analysis showed the mass of the peptide to be approximately 3,487.8 Da. N-terminal amino acid sequence analysis was performed, and 27 amino acids were identified. Because it has no similarity to other known bacteriocins, this bacteriocin was defined as a new bacteriocin and termed weissellicin 110.


2006 ◽  
Vol 69 (8) ◽  
pp. 1937-1943 ◽  
Author(s):  
PONGSAK RATTANACHAIKUNSOPON ◽  
PARICHAT PHUMKHACHORN

Lactobacillus plantarum N014 was isolated from nham, a traditional Thai fermented pork, and exhibited antimicrobial activity against Listeria monocytogenes. Its bacteriocin had a broad inhibitory spectrum toward both gram-positive and gram-negative bacteria. The bacteriocin activity was sensitive to all proteolytic enzymes used in this study, including papain, pepsin, pronase E, proteinase K, and trypsin, but was resistant to the other enzymes, such as α-amylase, lipase A, and lysozyme. Furthermore, activity was stable over various heat treatments and pH values. The bacteriocin exerted a bacteriolytic mode of action. It was produced during the exponential growth phase and reached its highest level as producer cells entered the stationary phase. Adsorption of the bacteriocin onto producer cells was pH-dependent. No bacteriocin adsorption was detected at pH 1 to 3, whereas 100% bacteriocin adsorption was found at pH 7. Plasmid isolation revealed that L. plantarum N014 contained no plasmids. From Tricine–sodium dodecyl sulfate–polyacrylamide gel electrophoresis and growth inhibition testing against L. monocytogenes, the estimated molecular mass of L. plantarum N014 bacteriocin was 8 kDa.


1989 ◽  
Vol 35 (5) ◽  
pp. 844-848
Author(s):  
D L Kalpaxis ◽  
E E Giannoulaki

Abstract Serum from a patient with hepatocellular carcinoma contained an abnormal isoenzyme of lactate dehydrogenase (LDH; EC 1.1.1.27), LDH-1ex, that on electrophoresis on 10-g/L agarose gel migrated anodally to the LDH-1 band. This isoenzyme was partly purified by ultrafiltration and preparative electrophoresis. Gel chromatography and sodium dodecyl sulfate/polyacrylamide gel electrophoresis studies of the resulting LDH-1ex preparation suggested that this isoenzyme is probably a tetramer made up of four single polypeptide chains (monomers), each having a molecular mass of about 32,000 Da. LDH-1ex was heat stable and reacted more readily with 2-hydroxybutyrate than did the slower migrating LDH-4 and LDH-5 isoenzymes. LDH-1ex showed no activity when lactate was omitted from the substrate solution or replaced by ethanol.


1999 ◽  
Vol 45 (1) ◽  
pp. 23-30
Author(s):  
Somchai Santiwatanakul ◽  
Noel R Krieg

Autolytic activity in the soluble and sediment fractions of sonicates of the spiral and the coccoid form of Campylobacter upsaliensis could not be demonstrated by native (nondenaturing) polyacrylamide gel electrophoresis (PAGE). Autolysins were detected, however, by using denaturing sodium dodecyl sulfate (SDS) - PAGE gels containing either purified Escherichia coli peptidoglycan or whole cells of Micrococcus luteus (Micrococcus lysodeikticus) as the turbid substrate, with subsequent renaturation by treatment with Triton X-100 buffer. In renaturing gels that contained Escherichia coli peptidoglycan, 14 putative autolytic bands ranging from 200 to 12 kDa were detected. In similar gels containing whole cells of M. luteus, only a single band appeared with a molecular mass of 34 kDa. This band corresponded to one of the bands present in the gels containing Escherichia coli peptidoglycan. This common autolysin was isolated by adsorbing it from Campylobacter upsaliensis soluble fractions onto M. luteus cells and then subjecting these cells to renaturing SDS-PAGE in gels containing Escherichia coli peptidoglycan. The 34-kDa autolysin differed from a single 51-kDa autolysin unique to the M. luteus cells, and when isolated from an SDS-PAGE gel, was pure when tested by isoelectric focusing. The N-terminal amino acid sequence analysis showed the first 15 amino acids of the 34-kDa autolysin to have 67% identity to a part of antigenic protein PEB4 of Campylobacter jejuni. The purified autolysin was used to immunize rabbits and the antibodies produced precipitated autolytic activity from cell lysates. The specificity of the antibodies was shown by Western blotting: only a single specific band occurred, with a molecular mass of 34 kDa, and thus it seems unlikely that the 34-kDa autolysin was derived from any of the other autolysins that were detected.Key words: autolysin, Campylobacter upsaliensis, zymogram, murein hydrolase.


2004 ◽  
Vol 70 (12) ◽  
pp. 7311-7320 ◽  
Author(s):  
Judit Marokházi ◽  
Katalin Lengyel ◽  
Szilvia Pekár ◽  
Gabriella Felföldi ◽  
András Patthy ◽  
...  

ABSTRACT Twenty strains (including eight phase variant pairs) of nematode-symbiotic and insect-pathogenic Photorhabdus bacteria were examined for the production of proteolytic enzymes by using a combination of several methods, including gelatin liquefaction, zymography coupled to native and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and activity measurement with two chromogen substrate types. Four protease activities (∼74, ∼55, ∼54, and ∼37 kDa) could be separated. The N-terminal sequences of three of the proteases were determined, and a comparison with sequences in databases allowed identification of these proteases as HEXXH metallopeptidases. Thus, the 74-kDa protease (described formerly as Php-B [J. Marokházi, G. Kóczán, F. Hudecz, L. Gráf, A. Fodor, and I. Venekei, Biochem. J. 379:633-640, 2004) is an ortholog of OpdA, a member the thimet oligopeptidase family, and the 55-kDa protease is an ortholog of PrtA, a HEXXH+H peptidase in clan MB (metzincins), while the 37-kDa protease (Php-C) belongs to the HEXXH+E peptidases in clan MA. The 54-kDa protease (Php-D) is a nonmetalloenzyme. PrtA and Php-C were zymographically detected, and they occurred in several smaller forms as well. OpdA could not be detected by zymography. PrtA, Php-C, and Php-D were secreted proteases; OpdA, in contrast, was an intracellular enzyme. OpdA activity was found in every strain tested, while Php-D was detected only in the Brecon/1 strain. There was significant strain variation in the secretion of PrtA and Php-C activities, but reduced activity or a lack of activity was not specific to secondary-phase variants. The presence of PrtA, OpdA, and Php-C activities could be detected in the hemolymph of Galleria melonella larvae 20 to 40 h postinfection. These proteases appear not to be directly involved in the pathogenicity of Photorhabdus, since strains or phase variants lacking any of these proteases do not show reduced virulence when they are injected into G. melonella larvae.


2012 ◽  
Vol 3 (4) ◽  
pp. 319-330 ◽  
Author(s):  
S.D. Todorov ◽  
L. Favaro ◽  
P. Gibbs ◽  
M. Vaz-Velho

Strain ST211CH, identified as a strain of Enterococcus faecium, isolated from Lombo produced a bacteriocin that inhibited the growth of Enterococcus spp., Listeria spp., Klebsiella spp., Lactobacillus spp., Pseudomonas spp., Staphylococcus spp. and Streptococcus spp. The mode of action of the bacteriocin named as bacteriocin ST211Ch was bactericidal against Enterococcus faecalis ATCC19443. As determined by Tricine-SDS-PAGE, the approximate molecular mass of the bacteriocin was 8.0 kDa. Loss in antimicrobial activity was recorded after treatment with proteolytic enzymes. Maximum activity of bacteriocin ST211Ch was measured in broth cultures of E. faecium strain ST211Ch after 24 h; thereafter, the activity was reduced. Bacteriocin ST211Ch remained active after exposure to various temperatures and pHs, as well as to Triton X-100, Tween-80, Tween-20, sodium dodecyl sulfate, NaCl, urea and EDTA. Effect of media components on production of bacteriocin ST211Ch was also studied. On the basis of PCR reactions targeting different bacteriocin genes, i.e. enterocins, curvacins and sakacins, no evidences for the presence of these genes in the total DNA of E. faecium strain ST211Ch was obtained. The bacterium most probably produced a bacteriocin different from those mentioned above. Based on the antimicrobial spectrum, stability and mode of action of bacteriocin ST211CH, E. faecium strain ST211Ch might be considered as a potential candidate with beneficial properties for use in biopreservation to control food spoilage bacteria.


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