Characterization of a Bacteriocin Produced by Enterococcus faecalis N1-33 and Its Application as a Food Preservative

2009 ◽  
Vol 72 (3) ◽  
pp. 524-530 ◽  
Author(s):  
TOMOMI HATA ◽  
MELAKU ALEMU ◽  
MIHO KOBAYASHI ◽  
CHISE SUZUKI ◽  
SUNEE NITISINPRASERT ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Marked Reduction ◽  
Pathogenic Bacteria ◽  
Culture Supernatant ◽  
Amino Acid Residues ◽  
Bacteriocin Activity ◽  
Food Preservative ◽  
Fermented Bamboo Shoot ◽  
Potential Use

A bacteriocin-producing strain, N1-33, isolated from fermented bamboo shoot was identified as Enterococcus faecalis. The pH-adjusted culture supernatant of this strain consisted of several peptides with bacteriocin activity, and the supernatant inhibited the growth of pathogenic bacteria such as Listeria monocytogenes. The major peptide with bacteriocin activity was purified, and the first 39 amino acid residues of the bacteriocin were found to be identical to enterocin MR10A produced by E. faecalis MRR10-3. Addition of the pH-adjusted and concentrated culture supernatant of strain N1-33 caused a marked reduction in the growth of Bacillus cereus in custard cream and L. monocytogenes in pickled cucumber. These results suggest the potential use of the bacteriocin produced by strain N1-33 in food biopreservation.

scholarly journals Incidence and characterisation of Bacillus cereus bacteriophages from Thua Nao, a Thai fermented soybean product

2021 ◽  
Vol 12 (1) ◽  
pp. 85-93
Author(s):  
Wallapat Phongtang ◽  
Ekachai Chukeatirote
Keyword(s):  
Bacillus Cereus ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Morphological Analysis ◽  
Food Poisoning ◽  
Fermented Soybean ◽  
Foodborne Pathogenic Bacteria ◽  
Ph Range ◽  
Potential Use

Abstract Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.

Cloning and Characterization of a Novel N-acetylglucosaminidase (AtlD) from Enterococcus faecalis

2018 ◽  
Vol 28 (1) ◽  
pp. 14-27 ◽  
Author(s):  
Carlos Eduardo Serrano-Maldonado ◽  
Israel García-Cano ◽  
Augusto González-Canto ◽  
Eliel Ruiz-May ◽  
Jose Miguel Elizalde-Contreras ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Heterologous Protein ◽  
Biochemical Characterization ◽  
Ph Values ◽  
Food Borne ◽  
Sds Page ◽  
Exclusion Chromatography

The <i>atlD</i> gene from<i></i> an <i>Enterococcus faecalis</i> strain isolated from a Mexican artisanal cheese was cloned, sequenced and expressed in <i>Escherichia coli</i> in order to perform a biochemical characterization<i>.</i> A partial amino acid sequence of the heterologous protein was obtained by LC-MS/MS, and it corresponded to a novel peptidoglycan hydrolase designated AtlD. Its molecular mass was 62–75 kDa, as determined by SDS-PAGE, zymography, Western blot, and exclusion chromatography. Electrofocusing rendered an isoelectric point (pI) of 4.8. It exhibited N-acetylglucosaminidase activity, with an optimal pH and temperature between 6–7 and 50°C, respectively. It retained 85% activity with NaCl at 1,000 mM, but it was susceptible to divalent ions, particularly Zn<sup>2+</sup>. It showed antibacterial activity against <i>Listeria monocytogenes</i>,<i> Staphylococcus aureus</i>, and enterococcal<i></i> strains of clinical origin. Due to the fact that it showed activity versus pathogenic bacteria, and because of its capabilities under ionic strength, temperature, and pH values present in food matrices, it could be applied as an additive in the food industry. This study will aid in the design of new antibacterial agents of natural origin to combat food-borne diseases, and it could be used as an industrial or hospital hygiene agent as well.

scholarly journals Production and Extraction Of Antibacterial Bacteriocin from Pediococcus sp. NWD 015

2015 ◽  
Vol 11 (2) ◽  
Author(s):  
N. Nofisulastri ◽  
Zaenal Bachruddin ◽  
Eni Harmayani
Keyword(s):  
Heat Treatment ◽  
Molecular Weight ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Enterococcus Faecalis ◽  
Storage Time ◽  
Bacteriocin Production ◽  
Proteinase K ◽  
Bacteriocin Activity

objectives were to study the growth pattern of Pediococcus sp. NWD 015 and bacteriocin activity, extractionand characterization of bacteriocin, and to determine the effect of storage time and temperature on bacteriocinactivity. Results showed that the bacteriocin activity increased during growth and reached the highest activity duringstationary phase. The maximum bacteriocin production reached after incubation of the cell for 12 h at 37oC in TGEbroth and decreased after 96 h incubation. Extraction with adsorbtion-desorbtion method could increased a specificactivity of bacteriocin. Bacteriocin from Pediococcus sp. NWD 015 is inactivated by Proteinase-K; however it is stillactive by heat treatment at 121oC for 15 min and over pH 2 – 11. Bacteriocin of Pediococcus sp. NWD 015 was effectiveagaints Enterococcus faecalis, Staphylococcus aureus, Eschericia coli, Listeria monocytogenes but not against Salmonellathypimurium. The molecular weight of bacteriocin is 4.95 kDa.Keywords : Bacteriocins, Pediococcus sp NWD 015.

scholarly journals Molecular Diversity of a Putative Virulence Factor: Purification and Characterization of Isoforms of an Extracellular Serine Glutamyl Endopeptidase of Enterococcus faecalis with Different Enzymatic Activities

2005 ◽  
Vol 187 (1) ◽  
pp. 266-275 ◽  
Author(s):  
Magdalena Kawalec ◽  
Jan Potempa ◽  
Jonathan L. Moon ◽  
James Travis ◽  
Barbara E. Murray
Keyword(s):  
Enterococcus Faecalis ◽  
Culture Supernatant ◽  
Glutamyl Endopeptidase ◽  
Putative Virulence Factor ◽  
Ph Optimum ◽  
Human Fibrinogen ◽  
Peptide Bonds ◽  
Gelatinase Activity ◽  
Group A

ABSTRACT A previously identified gene sprE of Enterococcus faecalis strain OG1 was shown to encode an extracellular serine protease that appears to belong to the glutamyl endopeptidase I staphylococcal group. A single form of SprE with a molecular mass of 25 kDa and a pH optimum between 7.0 and 7.5 was isolated from culture supernatant of wild-type E. faecalis strain OG1RF (TX4002); this form was apparently generated by cleavage of the Ser−1-Leu1 and Arg230-Leu231 peptide bonds of the secreted zymogen. In contrast, the culture supernatant of the gelatinase-null mutant, TX5264, with a nonpolar deletion of gelE which encodes the E. faecalis gelatinase, was found to contain several forms of SprE proteolytically processed on both the N and C termini; in addition to a full-length zymogen and a truncated zymogen, three mature forms of the SprE proteinase, Leu1-Ala237, Ser−1-Glu227, and Leu1-Glu227, were identified. As with the V8 proteinase of Staphylococcus aureus, the closest homologue of SprE, all of the active forms cleaved specifically Glu-Xaa peptide bonds but with substantially different efficiencies, while none was able to hydrolyze peptide bonds with Asp in the P1 position. The most active of all these enzyme forms against several substrates, including human fibrinogen and β-chain insulin, was the Ser−1-Glu227 (−1S-SprE) isolated from TX5264; −1S-SprE, in contrast to other forms of SprE, was unstable at 37°C, apparently due to autodegradation. In conclusion, our results demonstrate that sprE encodes a highly specific serine-type glutamyl endopeptidase, the maturation of which is dependent on the presence of gelatinase. In the absence of gelatinase activity, the aberrant processing of pro-SprE results in the appearance of a “superactive” form of the enzyme, −1S-SprE.

Characterization of a noncytotoxic bacteriocin from probiotic Lactobacillus plantarum DM5 with potential as a food preservative

2014 ◽  
Vol 5 (10) ◽  
pp. 2453-2462 ◽  
Author(s):  
Deeplina Das ◽  
Arun Goyal
Keyword(s):  
Human Cell ◽  
Probiotic Properties ◽  
Human Cell Lines ◽  
Bacteriocin Activity ◽  
Food Preservative ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
Probiotic Lactobacillus

Lb. plantarum DM5 exhibited in vitro probiotic properties and cholesterol assimilation activity. It displayed broad bacteriocin activity against several food borne pathogens. Cytotoxicity analysis of purified plantaricin DM5 on human cell lines revealed its nontoxic and biocompatible nature, rendering its use as bio-preservant.

scholarly journals LccA, an Archaeal Laccase Secreted as a Highly Stable Glycoprotein into the Extracellular Medium by Haloferax volcanii

2009 ◽  
Vol 76 (3) ◽  
pp. 733-743 ◽  
Author(s):  
Sivakumar Uthandi ◽  
Boutaiba Saad ◽  
Matthew A. Humbard ◽  
Julie A. Maupin-Furlow
Keyword(s):  
Culture Supernatant ◽  
Specific Activity ◽  
Haloferax Volcanii ◽  
Organic Substrates ◽  
Amino Acid Residues ◽  
Multicopper Oxidases ◽  
Absorbance Spectrum ◽  
Purification And Characterization ◽  
Extracellular Medium

ABSTRACT Laccases couple the oxidation of phenolic compounds to the reduction of molecular oxygen and thus span a wide variety of applications. While laccases of eukaryotes and bacteria are well characterized, these enzymes have not been described in archaea. Here, we report the purification and characterization of a laccase (LccA) from the halophilic archaeon Haloferax volcanii. LccA was secreted at high levels into the culture supernatant of a recombinant H. volcanii strain, with peak activity (170 ± 10 mU·ml− 1) at stationary phase (72 to 80 h). LccA was purified 13-fold to an overall yield of 72% and a specific activity of 29.4 U·mg− 1 with an absorbance spectrum typical of blue multicopper oxidases. The mature LccA was processed to expose an N-terminal Ala after the removal of 31 amino acid residues and was glycosylated to 6.9% carbohydrate content. Purified LccA oxidized a variety of organic substrates, including bilirubin, syringaldazine (SGZ), 2,2,-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and dimethoxyphenol (DMP), with DMP oxidation requiring the addition of CuSO4. Optimal oxidation of ABTS and SGZ was at 45°C and pH 6 and pH 8.4, respectively. The apparent K m values for SGZ, bilirubin, and ABTS were 35, 236, and 670 μM, with corresponding k cat values of 22, 29, and 10 s− 1, respectively. The purified LccA was tolerant of high salt, mixed organosolvents, and high temperatures, with a half-life of inactivation at 50°C of 31.5 h.

scholarly journals Technological characterization of lactic acid bacteria isolated from sheep milk for potential use as non-starter cultures

2019 ◽  
Vol 74 (1) ◽  
pp. 13-24
Author(s):  
Maria Rita Souto Dias ◽  
Andressa Fusieger ◽  
Amanda De Souza Motta
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
16S Rdna ◽  
Lactococcus Lactis ◽  
Enterococcus Faecalis ◽  
Starter Cultures ◽  
Sheep Milk ◽  
Potential Use ◽  
Tof Ms

O leite de ovelha possui diferentes propriedades físico-químicas, o que significa que seus derivados têm alto valor agregado. Parte dessas propriedades é conferida por bactérias lácticas que desempenham importantes atividades no leite cru. Esta pesquisa teve como objetivo analisar cinco bactérias lácticas previamente identificadas e avaliadas quanto a seus parâmetros de acidificação, proteólise, produção de diacetil e exopolissacarídeos, potencial atividade antimicrobiana e parâmetros de segurança. A identificação do gene 16S rDNA por sequenciamento mostrou concordância com os dados obtidos por MALDI-TOF/MS. As bactérias foram identificadas como Lactococcus lactis MRS1, Lactococcus lactis MRS2, Lactococcus lactis MRS5, Lactococcus lactis MRS6 e Enterococcus faecalis M173. Todos os isolados apresentaram o mesmo perfil de acidificação, mantendo o pH em 4,5 a partir de 6 horas de incubação, nas condições empregadas. Atividade proteolítica, capacidade de coexistência e produção de exopolissacarídeos foram observadas em todos os isolados testados. A produção de diacetil foi evidente nos isolados Lactococcus lactis MRS1 e Lactococcus lactis MRS2. Em relação à presença de atividade antimicrobiana, os isolados de Lactococcus lactis MRS6 e Enterococcus faecalis M173 inibiram todas as culturas testadas. Na avaliação dos parâmetros de segurança, nenhum dos isolados apresentou resistência de alto nível a antibióticos clinicamente importantes e não apresentaram produção de gelatinase e atividade hemolítica. Estes resultados fornecem uma informação importante sobre as potenciais bactérias a serem exploradas para a aplicação em produtos derivados de leite de ovelha, em condições de cultura starter ou adjuntas.

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