Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pediococcus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed2002

Production of bacteriocins from Lactococcus lactis subsp. lactis CECT 539 and Pediococcus acidilactici NRRL B-5627 using mussel-processing wastes.

The growth and bacteriocin production by Lactococcus lactis subsp. lactis CECT 539 and Pediococcus acidilactici NRRL B-5627 were investigated on mussel-processing wastes. Both bacteriocin productions were satisfactorily modelled using a modified form of the Luedeking and Piret expression, which includes a term for the influence of the pH reduction rate. Experimental data from cultures buffered at different initial concentrations (0, 0.03, 0.10 and 0.25 M) of both bacteria were used to fit and verify the model. The influence of total sugars, nitrogen, phosphorus and buffer concentration on nisin and pediocin production was also studied using response-surface methodology and empirical modelling. Enhanced nisin production (33 BU/ml) was achieved in media buffered with 0.10 M potassium hydrogen phthalate/NaOH. However, the highest levels of pediocin (368 BU/ml) were obtained in the non-buffered media.

Animals↗
PubMed2005

Fed-batch pediocin production by Pediococcus acidilactici NRRL B-5627 on whey.

Cell growth and pediocin production by Pediococcus acidilactici NRRL B-5627 on whey were compared by using batch fermentation and re-alkalized fed-batch fermentation. The batch fermentations were performed on DWG [DW (diluted whey) supplemented with 1% (w/v) glucose], DWYE [DW supplemented with 2% (w/v) yeast extract] and DWGYE (DW supplemented with 1% glucose plus 2% yeast extract) media. The fed-batch culture on DWYE medium was fed with a mixture of concentrated whey (48 g of total sugars/l) supplemented with 2% yeast extract and 400 g/l concentrated glucose. The re-alkalized fed-batch culture was characterized by higher biomass (6.57 g/l) and pediocin [517.6 BU (bacteriocin activity units)/ml] concentrations compared with the batch processes on MRS (de Man, Rogosa and Sharpe) broth (1.76 g/l and 493.2 BU/ml), DW (0.17 g/l and 57.7 BU/ml), DWG (0.14 g/l and 53.6 BU/ml), DWYE (1.43 g/l and 187.6 BU/ml) and DWGYE (1.28 g/l and 167.3 BU/ml) media. A mixed acid fermentation was observed during the growth of P. acidilactici NRRL B-5627 in the fed-batch culture on DWYE medium, and other products (acetic acid and ethanol) in addition to lactic acid accumulated in the medium. Mathematical models were set up to describe fed-batch production of biomass and pediocin by P. acidilactici. The models developed offer a better fit and a more realistic description of the experimental biomass and pediocin production data when compared with the logistic and Luedeking and Piret model.

Animals↗
PubMed2006

An improved and simplified method for the large-scale purification of pediocin PA-1 produced by Pediococcus acidilactici.

The bacteriocin pediocin PA-1 produced by Pediococcus acidilactici PAC 1.0 offers significant potential as a food preservative and as an antimicrobial agent in the medical area. However, low production yields and difficulties in obtaining significant amounts of pure pediocin PA-1 have limited, in part, its biochemical and physical characterization. In the present study, we describe a simple and more efficient purification strategy for pediocin PA-1. A hydrophobic interaction chromatography step using an octyl-Sepharose column was introduced for final purification and polishing. The new method is a scalable one, uses only two steps and yields highly purified pediocin PA-1 with a recovery as high as 73%, which is at least two to three times more than that of the methods reported so far. Highly purified, biologically active pediocin PA-1 of the correct molecular mass (4624 Da, with two disulphide bridges) was obtained. Fourier-transform infrared analysis runs at p2H 6 indicated that pediocin PA-1 was more structured than similar pediocin PA-1 samples purified using the earlier purification scheme.

Anti-Infective Agents↗
PubMed1999

Reduction of Escherichia coli O157:H7 by stimulated Pediococcus acidilactici.

This study was conducted to determine if stimulating the growth of meat starter culture (Pediococcus acidilactici) in a laboratory medium (Brain Heart Infusion broth +2.3% NaCl + 1.5% sucrose; LBHI) and during meat fermentation would control Escherichia coli O157:H7. In LBHI medium without P. acidilactici, the numbers of E. coli O157:H7 increased from 4.00 to 8.34 log10 cfu ml-1, whereas in the presence of P. acidilactici (approximately 6.0 log10 cfu ml-1) in LBHI, LBHIM (LBHI + 0.005% MnSO4), LBHIO (LBHI + 0.3 unit ml-1 Oxyrase), and LBHIMO (LBHI + M + O), the numbers of E. coli O157:H7 increased from 4.00 to 8.05, 7.50, 7.99, and 6.50 log10 cfu ml-1, respectively, after incubation at 40 degrees C for 15 h. During salami fermentation, the numbers of E. coli O157:H7 changed from 7.00 to 6.40 and 5.10 log10 cfu g-1 without and with P. acidilactici (approximately 7.0 log10 cfu g-1), respectively. Stimulated P. acidilactici by M, O, and MO further reduced the number of E. coli O157:H7 from 7.00 to 4.00, 4.80, and 3.65 log10 cfu g-1, respectively. The combination of MO was a better growth stimulator for P. acidilactici, which controlled E. coli O157:H7 in both systems (P < 0.05).

Animals↗
PubMed2000

Effect of some nutritional and environmental parameters on the production of diacetyl and on starch consumption by Pediococcus pentosaceus and Lactobacillus acidophilus in submerged cultures.

Three series of 5-day submerged cultures with Pediococcus pentosaceus MITJ-10 and Lactobacillus acidophilus Hansen 1748 were carried out in starch-based media, and the effect of cultural factors on the changes of starch, diacetyl and amylase activity determined. In axenic cultures, Ped. pentosaceus MITJ-10 produced more diacetyl (63.27 mg l(-1)) by adding glucose, yeast extract and CaCO3 (P < 0.01), at 28 degrees C (P < 0.05); but more starch was consumed (18.4 g l(-1)) in the absence of glucose (P < 0.01). Lact. acidophilus Hansen 1748 consumed more starch (26.56 g l(-1)) at 28 degrees C, with CaCO3, glucose (P < 0.01) and yeast extract (P < 0.05); however, the amylolytic activity (10077U l(-1)) was favoured at 35 degrees C (P < 0.01). Little starch was consumed in mixed cultures due to the low pH; nevertheless, diacetyl content rose to 135.76 mg l(-1) at 32 degrees C (P < 0.01). Therefore, both studied strains might be useful to produce aromatic extensors from starchy substrates. These natural aromatic extensors are of interest to the food industry.

Amylases↗
PubMed2001

Direct polymerase chain reaction detection of ropy Pediococcus damnosus strains in wine.

AIMS: Glucan-producing strains of Pediococcus damnosus are considered as spoilage micro-organisms because synthesis of glucan leads to an unacceptable viscosity of wine. In this report, we present a polymerase chain reaction (PCR) procedure to detect the presence of such strains in wines. METHODS AND RESULTS: We developed a direct DNA isolation method from the wine microflora using polyvinylpyrrolidone in order to decrease the polyphenolic concentration. The sequence of the plasmid involved in glucan production allowed the design of a primer pair usable for a specific and sensitive PCR procedure, leading to the amplification of a 563-bp fragment. CONCLUSION: The detection limit in wine was 102 cfu ml-1. The detection sensitivity could be increased by using a second primer pair in nested PCR assays. SIGNIFICANCE AND IMPACT OF THE STUDY: The method proved to be efficient for the early and sensitive detection of ropy Ped. damnosus strains during wine-making. Time-consuming culture and colony isolation steps are no longer needed.

Amino Acid Sequence↗
PubMed2001

Growth optimization of Pediococcus damnosus NCFB 1832 and the influence of pH and nutrients on the production of pediocin PD-1.

AIMS: Optimization of the growth of Pediococcus damnosus NCFB 1832 and the production of pediocin PD-1 by traditional fermentation methods. METHODS AND RESULTS: Fermentation studies were conducted in De Man Rogosa and Sharpe (MRS) broth (Oxoid), preadjusted to specific pH values, and in MRS broth supplemented with various nitrogen sources, MnSO4, MgSO4 and Tween 80. The production of pediocin PD-1 closely followed the growth curve of Ped. damnosus NCFB 1832. Maximum levels of bacteriocin activity (3249 AU ml(-1)/O.D.max) were recorded in MRS broth with an initial pH of 6.7. In media with an initial pH of 4.5 bacteriocin activity as low as 222 AU ml(-1)/O.D.max was recorded. The highest bacteriocin activity was recorded in growth conditions allowing the greatest pH variation (highest DeltapH). The addition of bacteriological peptone (1.7%, w/v), MnSO4 (0.014%, w/v) and Tween 80 (3%, v/v) to MRS and adjustment of the medium pH to 6.7 resulted in a further increase in activity (from 3249 to 5078 AU ml(-1)/O.D.max). The same medium, but with an initial pH of 6.2, resulted in an 82.5% decrease in bacteriocin activity. CONCLUSIONS: Pediocin PD-1 production is not only stimulated by the presence of specific growth factors (e.g., bacteriological peptone, MnSO4 or Tween 80), but may also be stimulated by the lowering in pH during growth (highest DeltapH), and thus also the amount of organic acids produced. SIGNIFICANCE AND IMPACT OF THE STUDY: The production of pediocin PD-1 by the wild-type producer strain was significantly improved by using a defined medium and traditional fermentation methods.

Anti-Bacterial Agents↗
PubMed2003

Substrate inhibition of Pediococcus acidilactici by glucose on a waste medium. Simulations and experimental results.

AIMS: The possibility of substrate inhibition by glucose on biomass and pediocin production was studied in cultures of Pediococcus acidilactici on a residual medium. METHODS AND RESULTS: Calculation of the substrate inhibition coefficient in the context of microbial growth is generally laborious, and very prone to experimental error. However, a simulation combining logistic and Monod kinetics equations demonstrates that quantitative evidence for this type of inhibition, without the possibility of misinterpretation, can be obtained through the comparison of punctual preasymptotic productions as a function of substrate concentration. SIGNIFICANCE AND IMPACT OF THE STUDY: It was concluded that glucose had an inhibitory effect on growth, but not on bacteriocin production.

Bacteriocins↗
PubMed1990

Vancomycin-resistant Pediococcus acidilactici: nine cases of bacteremia.

Pediococci, vancomycin-resistant gram-positive cocci, have been isolated from human specimens, but an association with clinical illness has not been established. Clinical and epidemiologic data were obtained on nine patients who had Pediococcus acidilactici isolated from blood. Patients were eight elderly adults with complicated medical problems and one infant with congenital jejunoileal atresia. Seven patients were hospitalized before P. acidilactici was isolated. Eight had received multiple antibiotics; however, only two had received vancomycin. In all cases there was a delay in correct bacterial identification, and the significance of the isolate was uncertain. There was no clearly identified syndrome associated with P. acidilactici bacteremia. All eight adults had fever and six had pneumonia potentially attributable to other causes. The findings underscore the importance of proper identification of vancomycin-resistant gram-positive cocci. P. acidilactici may be an opportunistic pathogen in severely compromised hosts; however, further observations are necessary to clarify its role in human disease.

Aged↗
PubMed1992

Purification and amino acid sequence of a bacteriocin produced by Pediococcus acidilactici.

A bacteriocin produced by Pediococcus acidilactici has been purified to homogeneity by a rapid and simple four-step purification procedure which includes ammonium sulphate precipitation, chromatography with a cation-exchanger and Octyl Sepharose, and reverse-phase chromatography. The purification resulted in an approximately 80,000-fold increase in the specific activity and about a 6-fold increase in the total activity. The amino acid composition and sequencing data indicated that the bacteriocin contained 43-44 amino acid residues. The predicted M(r) and isolectric point of the bacteriocin are about 4600 and 8.6, respectively. Comparing the amino acid sequence of this bacteriocin with the sequences of leucocin A-UAL 187, sakacin P and curvacin A (bacteriocins produced by Leuconostoc gelidum, Lactobacillus sake and Lactobacillus curvatus, respectively) revealed that all four bacteriocins had in their N-terminal region the sequence Tyr-Gly-Asn-Gly-Val-Xaa-Cys, indicating that this concensus sequence is of fundamental importance for this group of bacteriocins. The bacteriocin from P. acidilactici and sakacin P were very similar, having at least 25 common amino acid residues. The sequence similarity was greatest in the N-terminal half of the molecules--17 of the first 19 residues were common--indicating the fundamental importance of this region. Leucocin A-UAL 187 and curvacin A had, respectively, at least 16 and 13 amino acid residues in common with the bacteriocin from P. acidilactici.

Amino Acid Sequence↗
PubMed2000

Genomic subpopulations within the species Pediococcus acidilactici detected by multilocus typing analysis: relationships between pediocin AcH/PA-1 producing and non-producing strains.

A high degree of genetic polymorphism among P. acidilactici strains was highlighted by a multilocus typing approach analysing several housekeeping genes and by sampling the whole genome using random amplified polymorphic DNA (RAPD) fingerprint analysis performed by using a single primer pedA gene targeted in low-stringency amplification conditions. Restriction fragment length polymorphism of the rpoC, ldhD/L and mle genes, and a modified RAPD analysis, permitted the grouping of Pediococcus acidilactici strains in seven genotypes (I-VII). Genotypic results obtained by analysing housekeeping genes involved in the transcription/translation machinery and in primary metabolism were supported by phylogenetic analysis based on the partial 16S rDNA sequencing of a reference strain of each of the seven clusters obtained. Three of the seven genotypes detected showed relationships with pediocin AcH/PA-1 production and carbohydrate fermentation patterns: all pediocin-producing and sucrose-positive strains were grouped in genotype VII, melibiose-, sucrose- and raffinose-positive strains in genotype VI, and arabinose-positive strains in genotype V.

Bacterial Typing Techniques↗
PubMed1976

The nutritional requirements of methicillin-dependent and -resistant strains of Pediococcus cerevisiae.

A new methicillin-dependent and -resistant substrain (called MRD) of Pediococcus cerevisiae was developed by serial passages followed by replica-plating. Other methicillin-resistant, but not -dependent, substrains were isolated after treatment of the same parent strain with a mutagen. A methicillin-independent partial revertant, still resistant to the drug, was isolated from the original methicillin-dependent and -resistant substrain (CRD) developed several years ago. The requirements of some of these strains for acetate, vitamins and amino acids were compared. All except the parent methicillin-sensitive strain required pantothenate for growth, but no other consistent differences were found. The parent, but not strain CRD, grew without lysine added to the medium, though 19 other amino acids were needed by each strain. Both of these strains fermented glucose to lactate (mainly the L-isomer) in the absence or presence of methicillin.

Acetates↗
PubMed2006

Data mining and characterization of a novel pediocin-like bacteriocin system from the genome of Pediococcus pentosaceus ATCC 25745.

The genome of Pediococcus pentosaceus ATCC 25745 contains a gene cluster that resembles a regulated bacteriocin system. The gene cluster has an operon-like structure consisting of a putative pediocin-like bacteriocin gene (termed penA) and a potential immunity gene (termed peiA). Genetic determinants involved in bacteriocin transport and regulation are also found in proximity to penA and peiA but the so-called accessory gene involved in transport and the inducer gene involved in regulation are missing. Consequently, this bacterium is a poor bacteriocin producer. To analyse the potency of the putative bacteriocin operon, the two genes penA-peiA were heterologously expressed in a Lactobacillus sakei host that contains the complete apparatus for gene activation, maturation and externalization of bacteriocins. It was demonstrated that the heterologous host expressing penA and peiA produced a strong bacteriocin activity; in addition, the host became immune to its own bacteriocin, identifying the gene pair penA-peiA as a potent bacteriocin system. The novel pediocin-like bacteriocin, termed penocin A, has an isotopic mass [M+H]+ of 4684.6 Da as determined by mass spectrometry; this value corresponds well to the expected size of the mature 42 aa peptide containing a disulfide bridge. The bacteriocin is heat-stable but protease-sensitive and has a calculated pI of 9.45. Penocin A has a relatively broad inhibition spectrum, including pathogenic Listeria and Clostridium species. Immediately upstream of the regulatory genes reside some features that resemble remnants of a disrupted inducer gene. This degenerate gene was restored and shown to encode a double-glycine leader-containing peptide. Furthermore, expression of the restored gene triggered high bacteriocin production in P. pentosaceus ATCC 25745, thus confirming its role as an inducer in the pen regulon.

Amino Acid Sequence↗
PubMed1988

Purification, characterization and antimicrobial spectrum of a bacteriocin produced by Pediococcus acidilactici.

An antimicrobial peptide designated pediocin AcH was isolated from Pediococcus acidilactici strain H. The pediocin AcH was purified by ion exchange chromatography. The molecular weight of pediocin AcH was determined by SDS-PAGE to be about 2700 daltons. Pediocin AcH was sensitive to proteolytic enzymes resistant to heat and organic solvents, and active over a wide range of pH. Pediocin AcH exhibited inhibition against several food spoilage bacteria and foodborne pathogens including Staphylococcus aureus, Clostridium perfringens and Listeria monocytogenes. It was bactericidal to sensitive cells and acted very rapidly. The bactericidal effect was not produced by either cell lysis or apparent loss of membrane permeability.

Bacteria↗
PubMed1990

Antigenic property of pediocin AcH produced by Pediococcus acidilactici H.

Pediocin AcH, a bacteriocin of Pediococcus acidilactici H, inhibits the growth of several food spoilage and pathogenic bacteria. The antigenic property of partially purified pediocin AcH was tested by immunizing mice and a rabbit. Pediocin AcH was not immunogenic in these animals as determined by immunoblotting even after conjugation to bovine serum albumin. The non-immunogenic nature of pediocin AcH, its non-toxicity to laboratory animals and its hydrolysis by gastric proteolytic enzymes may be considered favourably in its possible use as a food preservative.

Animals↗
PubMed1991

Use of DNA probes in the study of silage colonization by Lactobacillus and Pediococcus strains.

A technique to monitor lactic acid bacteria inoculants in silage, based on specific DNA probes, was developed and used to evaluate the colonization properties of two strains of Lactobacillus plantarum and one strain of Pediococcus pentosaceus which were used as maize silage inoculants in farm conditions. The results indicated that these three strains were able to dominate the natural microflora of the silage, representing more than the 95% of the bacterial biomass of the maize silage. These studies indicate that the colony hybridization with specific DNA probes may be an effective method for monitoring bacteria and evaluating the colonization properties of inoculants in maize silage.

Animals↗
PubMed1993

Purification, partial characterization and plasmid-linkage of pediocin SJ-1, a bacteriocin produced by Pediococcus acidilactici.

Pediococcus acidilactici SJ-1, isolated from a naturally-fermented meat product, produced an antibacterial agent active against selected strains of Lactobacillus spp., Clostridium perfringens and Listeria monocytogenes. The agent was bactericidal against sensitive indicators, and sensitive to proteolytic enzymes; it was identified as a bacteriocin, and was designated as pediocin SJ-1. It was stable over a wide pH range (3-9), and apparently most stable in the lower part of that range. At pH 3.6, pediocin SJ-1 was stable at heat-processing temperatures within the range 65-121 degrees C; its activity decreased significantly, however, when it was heated at pH 7.0. The activity of pediocin SJ-1 on sensitive indicator cells was lost in the presence of alpha-amylase, suggesting that it contains a glyco moiety, necessary for its antibacterial action. Native pediocin SJ-1 exists in the form of monomers and aggregates (with molecular weights in the range 80-150 kDa). Pediocin SJ-1 was purified 262-fold by direct application of cell-free supernatant fluids to a cation-exchange chromatography column, and was resolved by SDS-PAGE as a single peptide band with a MW of ca 4 kDa. The original pediocin SJ-1-producing strain (bac+) harbours three plasmids of 4.6, 23.5, and 45.7 MDa. Production of pediocin SJ-1, but not immunity to SJ-1, is associated with the 4.6 MDa plasmid.

Bacteriocins↗