| 1. |
Dobson CM,
Deneer H,
Lee S,
Hemmingsen S,
Glaze S,
Ziola B,
( 2002 ) Phylogenetic analysis of the genus Pediococcus, including Pediococcus claussenii sp. nov., a novel lactic acid bacterium isolated from beer. PMID : 12508860 : DOI : 10.1099/00207713-52-6-2003 Abstract >>
Pediococci are found in foods and on plants and as beer-spoilage agents. The goal of the present study was to use the DNA sequences of the first three variable regions of the 165 rRNA gene, the 16S-23S rRNA internally transcribed spacer region sequence and approximately a third of the 60 kDa heat-shock protein gene to elucidate phylogenetic groupings within the genus Pediococcus. Phylogenetic trees were created with sequence data from 31 Pediococcus and three Lactobacillus isolates. Complete 16S rRNA gene sequences from selected Pediococcus isolates were also examined. The results were interpreted in relation to the currently accepted Pediococcus species. We found that, where previously done, speciation of many Pediococcus isolates is inaccurate. Also, one grouping of seven isolates did not include any currently recognized Pediococcus species type isolate. Our phylogenetic analyses support the conclusion that these seven isolates, all of brewing spoilage origin, belong to a novel species, for which the name Pediococcus claussenii sp. nov. is proposed (type strain P06(T0 = ATCC BAA-344(T) = DSM 14800(T)). Phylogenetic analysis has therefore helped to resolve problems surrounding species identification of Pediococcus isolates.
|
2. |
Naumov DG,
Livshits VA,
( N/A ) [Molecular structure of the locus for sucrose utilization by Lactobacillus plantarum: comparison with Pediococcus pentosaceus]. PMID : 11234378 : Abstract >>
Structure of the sucrose utilization locus in a Lactobacillus plantarum type strain was studied using PCR and Southern hybridization. Restriction map analysis revealed its high similarity to the sequenced sucrose utilization locus of Pediococcus pentosaceus pSRQ1. The L. plantarum locus proved containing oppositely oriented scrA and the scrBRagl operon, but not agaS. The L. plantarum sucrase gene (scrB) was partly sequenced. A higher (98.6%) homology was revealed between scrB than between the 16S rRNA genes of L. plantarum and P. pentosaceus, suggesting horizontal transfer of the sucrose utilization locus between the genera of lactic acid bacteria. Amino acid sequence analysis showed that the ScrB proteins of the two species belong to a subfamily of glycosyl hydrolase family GH32 which includes various beta-fructosidases.
|
3. |
Heinz M,
von Wintzingerode F,
Moter A,
Halle E,
Lohbrunner H,
Kaisers U,
Neuhaus P,
Halle E,
( 2000 ) A case of septicemia with Pediococcus acidilactici after long-term antibiotic treatment. PMID : 11205633 : DOI : 10.1007/s100960000409 Abstract >>
Presented here is a case of septicemia caused by an uncommon, multiresistant, gram-positive microorganism (Pediococcus acidilactici) after long-term antibiotic treatment. Pediococcus spp. are rarely cultivated from clinical specimens, and species differentiation is difficult due to the paucity of phenotypic traits. In this case, a polyphasic approach consisting of phenotypic and molecular genetic analyses was used, and the identification of Pediococcus acidilactici was conclusive. Precise identification and antimicrobial susceptibility testing of rarely isolated bacteria are required in order to provide adequate treatment to infected patients and to determine the pathogenic role of these organisms.
|
4. |
Barthelmebs L,
Lecomte B,
Divies C,
Cavin JF,
( 2000 ) Inducible metabolism of phenolic acids in Pediococcus pentosaceus is encoded by an autoregulated operon which involves a new class of negative transcriptional regulator. PMID : 11073918 : DOI : 10.1128/jb.182.23.6724-6731.2000 PMC : PMC111416 Abstract >>
Pediococcus pentosaceus displays a substrate-inducible phenolic acid decarboxylase (PAD) activity on p-coumaric acid. Based on DNA sequence homologies between the three PADs previously cloned, a DNA probe of the Lactobacillus plantarum pdc gene was used to screen a P. pentosaceus genomic library in order to clone the corresponding gene of this bacteria. One clone detected with this probe displayed a low PAD activity. Subcloning of this plasmid insertion allowed us to determine the part of the insert which contains a 534-bp open reading frame (ORF) coding for a 178-amino-acid protein presenting 81.5% of identity with L. plantarum PDC enzyme. This ORF was identified as the padA gene. A second ORF was located just downstream of the padA gene and displayed 37% identity with the product of the Bacillus subtilis yfiO gene. Subcloning, transcriptional analysis, and expression studies with Escherichia coli of these two genes under the padA gene promoter, demonstrated that the genes are organized in an autoregulated bicistronic operonic structure and that the gene located upstream of the padA gene encodes the transcriptional repressor of the padA gene. Transcription of this pad operon in P. pentosaceus is acid phenol dependent.
|
5. |
Squartini A,
Giacomini A,
( 2000 ) Nucleotide sequence and analysis of plasmid pMD136 from Pediococcus pentosaceus FBB61 (ATCC43200) involved in pediocin A production. PMID : 10686129 : DOI : 10.1006/plas.1999.1447 Abstract >>
The complete sequence of the 19515-bp plasmid pMD136 from Pediococcus pentosaceus FBB61 (ATCC43200) has been determined. This plasmid is involved in Pediocin A production, a bacteriocin active against a wide range of gram-positive bacteria. It appears to replicate via a theta mechanism, with structures closely related to those of many lactococcal plasmids. Genes homologous to mobilization functions are also present, which are similar in sequence and arrangement to mobA, mobB, and mobC of some staphylococcal plasmids, although the last one contains a deletion in its central part. The region involved in bacteriocin activity has been limited to a 9.4-kb fragment, containing 10 open reading frames organized in a single operon. Since Pediocin A has a molecular weight of about 80 kDa (Piva and Headon, Microbiology, 140, 697-702, 1994), and a gene long enough to encode it is not present in pMD136, it is proposed that genes residing on the plasmid are responsible for the regulation of bacteriocinogenic activity. Gene arrangement and sequence homologies suggest the presence of a two-component-like regulatory mechanism.
|
6. |
Kim IK,
Kim MK,
Kim JH,
Yim HS,
Cha SS,
Kang SO,
( 2007 ) High resolution crystal structure of PedB: a structural basis for the classification of pediocin-like immunity proteins. PMID : 17537233 : DOI : 10.1186/1472-6807-7-35 PMC : PMC1904221 Abstract >>
Pediocin-like bacteriocins, ribosomally-synthesized antimicrobial peptides, are generally coexpressed with cognate immunity proteins in order to protect the bacteriocin-producer from its own bacteriocin. As a step for understanding the mode of action of immunity proteins, we determined the crystal structure of PedB, a pediocin-like immunity protein conferring immunity to pediocin PP-1. The 1.6 A crystal structure of PedB reveals that PedB consists of an antiparallel four-helix bundle with a flexible C-terminal end. PedB shows structural similarity to an immunity protein against enterocin A (EntA-im) but some disparity to an immunity protein against carnobacteriocin B2 (ImB2) in both the C-terminal conformation and the local structure constructed by alpha3, alpha4, and their connecting loop. Structure-inspired mutational studies reveal that deletion of the last seven residues of the C-terminus of PedB almost abolished its immunity activity. The fact that PedB, EntA-im, and ImB2 share a four-helix bundle structure strongly suggests the structural conservation of this motif in the pediocin-like immunity proteins. The significant difference in the core structure and the C-terminal conformation provides a structural basis for the classification of pediocin-like immunity proteins. Our mutational study using C-terminal-shortened PedBs and the investigation of primary sequence of the C-terminal region, propose that several polar or charged residues in the extreme C-terminus of PedB which is crucial for the immunity are involved in the specific recognition of pediocin PP-1.
|
7. |
Van der Meulen R,
Grosu-Tudor S,
Mozzi F,
Vaningelgem F,
Zamfir M,
de Valdez GF,
De Vuyst L,
( 2007 ) Screening of lactic acid bacteria isolates from dairy and cereal products for exopolysaccharide production and genes involved. PMID : 17716765 : DOI : 10.1016/j.ijfoodmicro.2007.07.014 Abstract >>
A total of 174 lactic acid bacteria (LAB) strains isolated from dairy and cereal products were screened for the production of exopolysaccharides (EPS). Therefore, a rapid screening method was developed based on ultrafiltration and gel permeation chromatography. Furthermore, a screening through the polymerase chain reaction (PCR) was performed with primer pairs targeting different genes involved in EPS production. Nine isolates produced a homopolysaccharide of the glucan type, whereas only one strain produced a heteropolysaccharide. The production of a glucan by a strain of Lactococcus lactis and the production of a heteropolysaccharide by a strain of Lactobacillus curvatus are reported for the first time. The PCR screening revealed many positive strains. For three of the ten EPS-producing strains, no corresponding genes could be detected. Furthermore, a lot of strains possessed one or more eps genes but did not produce an EPS. Therefore, a screening on the molecular level should always be accompanied by another screening method that is able to distinguish true EPS producer strains from non-producing ones. Statistical analysis did not reveal any relationship between the type and origin of the strains, the presence or absence of a capsular polysaccharide or EPS, and the presence or absence of eps genes.
|
8. |
Scheirlinck I,
Van der Meulen R,
Van Schoor A,
Vancanneyt M,
De Vuyst L,
Vandamme P,
Huys G,
( 2007 ) Influence of geographical origin and flour type on diversity of lactic acid bacteria in traditional Belgian sourdoughs. PMID : 17675431 : DOI : 10.1128/AEM.00894-07 PMC : PMC2075033 Abstract >>
A culture-based approach was used to investigate the diversity of lactic acid bacteria (LAB) in Belgian traditional sourdoughs and to assess the influence of flour type, bakery environment, geographical origin, and technological characteristics on the taxonomic composition of these LAB communities. For this purpose, a total of 714 LAB from 21 sourdoughs sampled at 11 artisan bakeries throughout Belgium were subjected to a polyphasic identification approach. The microbial composition of the traditional sourdoughs was characterized by bacteriological culture in combination with genotypic identification methods, including repetitive element sequence-based PCR fingerprinting and phenylalanyl-tRNA synthase (pheS) gene sequence analysis. LAB from Belgian sourdoughs belonged to the genera Lactobacillus, Pediococcus, Leuconostoc, Weissella, and Enterococcus, with the heterofermentative species Lactobacillus paralimentarius, Lactobacillus sanfranciscensis, Lactobacillus plantarum, and Lactobacillus pontis as the most frequently isolated taxa. Statistical analysis of the identification data indicated that the microbial composition of the sourdoughs is mainly affected by the bakery environment rather than the flour type (wheat, rye, spelt, or a mixture of these) used. In conclusion, the polyphasic approach, based on rapid genotypic screening and high-resolution, sequence-dependent identification, proved to be a powerful tool for studying the LAB diversity in traditional fermented foods such as sourdough.
|
9. |
Renouf V,
Claisse O,
Lonvaud-Funel A,
( 2006 ) rpoB gene: a target for identification of LAB cocci by PCR-DGGE and melting curves analyses in real time PCR. PMID : 16626824 : DOI : 10.1016/j.mimet.2006.03.008 Abstract >>
Lactic acid bacteria (LAB) are essential in the quality of many fermented beverages like beer, cider and wine. In the two later cases, they convert malic acid into lactic acid during the malolactic fermentation. After fermentation, microbial stabilization is needed to prevent the development of spoilage bacteria species. Among them, cocci lead to different alterations: Pediococcus sp., and some strains of Leuconostoc mesenteroides and Oenococcus oeni can produce exopolysaccharides which modify wine viscosity and lead to ropiness. They also can produce acetic acid, biogenic amine, ethyl carbamate and volatile phenols. Therefore detection and identification are crucial. Results of phenotypic tests and DNA-DNA probes are not accurate enough. 16S RNA gene which is currently used for bacterial species identification presents intraspecies heterogeneity. The rpoB gene is an alternative to this limitation. However previous PCR targeting partial sequence of rpoB gene could not delimit cocci species. Therefore we compared the rpoB gene sequence of the six main cocci species found in fermented beverages: P. damnosus, P. dextrinicus, P. parvulus, P. pentosaceus, L. mesenteroides and O. oeni. The most discriminating partial sequence of the rpoB gene was chosen for designing primers. By PCR-DGGE the reliability of these primers was verified. It was controlled in a mixture of several cocci and other lactic acid bacteria (Lactobacillus sp.). Then we adapted the primers and the PCR conditions in order to achieve the identification of cocci species by real time PCR program including the fluorescent dye SYBR Green I, which gives faster results. PCR melt curves were established and a specific T(m) was attributed to each species.
|
10. |
Alegre MT,
Rodríguez MC,
Mesas JM,
( 2005 ) Nucleotide sequence, structural organization and host range of pRS4, a small cryptic Pediococcus pentosaceus plasmid that contains two cassettes commonly found in other lactic acid bacteria. PMID : 16054305 : DOI : 10.1016/j.femsle.2005.07.003 Abstract >>
The complete nucleotide sequence of the cryptic plasmid pRS4 (3550 bp) from Pediococcus pentosaceus RS4 was determined. Sequence analysis revealed the presence of three open reading frames (ORFs). The putative protein coded by ORF 1 showed 93% identity with the mobilization protein of Lactobacillus casei plasmid pLC88 and 94% identity with a sequenced fragment of the mobilization protein of P. damnosus plasmid pF8801, suggesting a common origin for these three mobilization proteins. The putative protein coded by ORF 2 showed 92% identity with the replication protein of L. plantarum plasmid pWCFS101, a plasmid that replicates via the rolling circle (RC) mechanism, suggesting a similar replication mechanism for pRS4. Supporting this hypothesis, a putative double strand origin (dso) and a region with palindromic sequences that could function as single strand origin (sso), were detected in pRS4. A function could not be assigned to ORF 3. Since ORF 1 exhibits high identity with L. casei plasmid pLC88 but lower identity (58%) with other Lactobacillus plasmids, and ORF 2 exhibits high identity with the L. plantarum plasmid pWCFS101 but lower identity (55-58%) with other Lactobacillus plasmids (including pLC88), two independent cassettes, from different sources, seem to be involved in the structure of pRS4. Plasmids derived from pRS4 containing the chloramphenicol resistance gene were successfully electrotransformed in L. plantarum, L. casei, P. pentosaceus, and Pediococcus acidilactici, suggesting that pRS4 could be used as a cloning vector for lactic acid bacteria. To our knowledge pRS4 is the first RC-replicating plasmid of P. pentosaceus that has been completely sequenced and used as cloning vector.
|
11. |
Miller KW,
Ray P,
Steinmetz T,
Hanekamp T,
Ray B,
( 2005 ) Gene organization and sequences of pediocin AcH/PA-1 production operons in Pediococcus and Lactobacillus plasmids. PMID : 15613003 : DOI : 10.1111/j.1472-765X.2004.01627.x Abstract >>
To determine the locations and sequences of pediocin AcH production genes in Pediococcus parvulus ATO77 from vegetables, Lactobacillus plantarum WHE92 from Muenster cheese, and a lactose-fermenting isolate Pediococcus pentosaceus S34 from buffalo milk. Plasmid curing, Southern blot hybridization, and DNA sequence analysis indicate that pediocin AcH production genes are encoded by highly similar operons in unique plasmids designated pATO77 from P. parvulus ATO77, pS34 from P. pentosaceus S34, and pWHE92 from Lact. plantarum WHE92. Structure, immunity and secretion system genes are linked together in the operons, and the promoter sequences are the same. The amino acid sequences of the encoded proteins are highly conserved between plasmids. Pediocin AcH production genes are located within a plasmid-borne operon cassette in all lactic acid bacterial strains examined to date. All four genes needed for production are present within a single plasmid in each strain. This is the first demonstration that the expression of a class IIa bacteriocin is directed by a common gene cassette that has been disseminated to unique plasmids in different genera of lactic acid bacteria. These plasmids should be useful for expressing pediocin AcH in Pediococcus and Lactobacillus strains used in food production.
|
12. |
Asteri IA,
Boutou E,
Anastasiou R,
Pot B,
Vorgias CE,
Tsakalidou E,
Papadimitriou K,
( 2011 ) In silico evidence for the horizontal transfer of gsiB, a �m(B)-regulated gene in gram-positive bacteria, to lactic acid bacteria. PMID : 21421783 : DOI : 10.1128/AEM.02569-10 PMC : PMC3126443 Abstract >>
gsiB, coding for glucose starvation-inducible protein B, is a characteristic member of the �m(�E) stress regulon of Bacillus subtilis and several other Gram-positive bacteria. Here we provide in silico evidence for the horizontal transfer of gsiB in lactic acid bacteria that are devoid of the �m(�E) factor.
|
13. |
Morovic W,
Hibberd AA,
Zabel B,
Barrangou R,
Stahl B,
( 2016 ) Genotyping by PCR and High-Throughput Sequencing of Commercial Probiotic Products Reveals Composition Biases. PMID : 27857709 : DOI : 10.3389/fmicb.2016.01747 PMC : PMC5093124 Abstract >>
Recent advances in microbiome research have brought renewed focus on beneficial bacteria, many of which are available in food and dietary supplements. Although probiotics have historically been defined as microorganisms that convey health benefits when ingested in sufficient viable amounts, this description now includes the stipulation "well defined strains," encompassing definitive taxonomy for consumer consideration and regulatory oversight. Here, we evaluated 52 commercial dietary supplements covering a range of labeled species using plate counting and targeted genotyping. Strain identities were assessed using methods recently published by the United States Pharmacopeial Convention. We also determined the relative abundance of individual bacteria by high-throughput sequencing (HTS) of the 16S rRNA sequence using paired-end 2 �� 250 bp Illumina MiSeq technology. Using these methods, we tested the hypothesis that products do contain the quantitative and qualitative list of labeled microbial species. We found that 17 samples (33%) were below label claim for CFU prior to their expiration dates. A multiplexed-PCR scheme showed that only 30/52 (58%) of the products contained a correctly labeled classification, with issues encompassing incorrect taxonomy, missing species, and un-labeled species. The HTS revealed that many blended products consisted predominantly of Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis. These results highlight the need for reliable methods to determine the correct taxonomy and quantify the relative amounts of mixed microbial populations in commercial probiotic products.
|
14. |
Lee JY,
Kwak MS,
Roh JB,
Kim K,
Sung MH,
( 2017 ) Microbial �]-Galactosidase of Pediococcus pentosaceus ID-7: Isolation, Cloning, and Molecular Characterization. PMID : 27994214 : DOI : 10.4014/jmb.1611.11015 Abstract >>
Pediococcus pentosaceus ID-7 was isolated from kimchi, a Korean fermented food, and it showed high activity for lactose hydrolysis. The �]-galactosidase of P. pentosaceus ID-7 belongs to the GH2 group, which is composed of two distinct proteins. The heterodimeric LacLM type of �]-galactosidase found in P. pentosaceus ID-7 consists of two genes partially overlapped, lacL and lacM encoding LacL (72.2 kDa) and LacM (35.4 kDa). In this study, Escherichia coli MM294 was used for the production of LacL, LacM, and LacLM. These three types of recombinant proteins were expressed, purified, and characterized. The specific activities of LacLM and LacL were 339 and 31 U/mg, respectively. However, activity was not detected with LacM alone. The optimal pH of LacLM and LacL was pH 7.5 and pH 7.0, and the optimal temperature of LacLM and LacL was 40�XC and 50�XC, respectively. The optimal temperature changes indicate that LacLM is able to achieve higher activity at a relatively lower temperature. LacLM was strongly activated by Mg2+, Mn2+, and Zn2+, which was not true for LacL. Consistent with this, EDTA strongly inactivated LacLM and LacL, but the presence of reducing agents did not dramatically alter the activity. Taken together, multiple alignment of amino acid sequences and phylogenetic analysis results of LacL and LacM of P. pentosaceus ID-7 suggest the evolution of LacL into LacLM and that the use of divalent metal ions results in higher activity.
|
15. |
Sun Z,
Harris HM,
McCann A,
Guo C,
Argimón S,
Zhang W,
Yang X,
Jeffery IB,
Cooney JC,
Kagawa TF,
Liu W,
Song Y,
Salvetti E,
Wrobel A,
Rasinkangas P,
Parkhill J,
Rea MC,
O'Sullivan O,
Ritari J,
Douillard FP,
Paul Ross R,
Yang R,
Briner AE,
Felis GE,
de Vos WM,
Barrangou R,
Klaenhammer TR,
Caufield PW,
Cui Y,
Zhang H,
O'Toole PW,
( 2015 ) Expanding the biotechnology potential of lactobacilli through comparative genomics of 213 strains and associated genera. PMID : 26415554 : DOI : 10.1038/ncomms9322 PMC : PMC4667430 Abstract >>
Lactobacilli are a diverse group of species that occupy diverse nutrient-rich niches associated with humans, animals, plants and food. They are used widely in biotechnology and food preservation, and are being explored as therapeutics. Exploiting lactobacilli has been complicated by metabolic diversity, unclear species identity and uncertain relationships between them and other commercially important lactic acid bacteria. The capacity for biotransformations catalysed by lactobacilli is an untapped biotechnology resource. Here we report the genome sequences of 213 Lactobacillus strains and associated genera, and their encoded genetic catalogue for modifying carbohydrates and proteins. In addition, we describe broad and diverse presence of novel CRISPR-Cas immune systems in lactobacilli that may be exploited for genome editing. We rationalize the phylogenomic distribution of host interaction factors and bacteriocins that affect their natural and industrial environments, and mechanisms to withstand stress during technological processes. We present a robust phylogenomic framework of existing species and for classifying new species.
|
16. |
Murphree CA,
Heist EP,
Moe LA,
( 2014 ) Antibiotic resistance among cultured bacterial isolates from bioethanol fermentation facilities across the United States. PMID : 24748439 : DOI : 10.1007/s00284-014-0583-y Abstract >>
Bacterial contamination of fuel ethanol fermentations by lactic acid bacteria (LAB) can have crippling effects on bioethanol production. Producers have had success controlling bacterial growth through prophylactic addition of antibiotics to fermentors, yet concerns have arisen about antibiotic resistance among the LAB. Here, we report on mechanisms used by 32 LAB isolates from eight different US bioethanol facilities to persist under conditions of antibiotic stress. Minimum inhibitory concentration assays with penicillin, erythromycin, and virginiamycin revealed broad resistance to each of the antibiotics as well as high levels of resistance to individual antibiotics. Phenotypic assays revealed that antibiotic inactivation mechanisms contributed to the high levels of individual resistances among the isolates, especially to erythromycin and virginiamycin, yet none of the isolates appeared to use a �]-lactamase. Biofilm formation was noted among the majority of the isolates and may contribute to persistence under low levels of antibiotics. Nearly all of the isolates carried at least one canonical antibiotic resistance gene and many carried more than one. The erythromycin ribosomal methyltransferase (erm) gene class was found in 19 of 32 isolates, yet a number of these isolates exhibit little to no resistance to erythromycin. The erm genes were present in 15 isolates that encoded more than one antibiotic resistance mechanism, suggestive of potential genetic linkages.
|
17. |
Thumu SC,
Halami PM,
( 2012 ) Presence of erythromycin and tetracycline resistance genes in lactic acid bacteria from fermented foods of Indian origin. PMID : 22644346 : DOI : 10.1007/s10482-012-9749-4 Abstract >>
Lactic acid bacteria (LAB) resistant to erythromycin were isolated from different food samples on selective media. The isolates were identified as Enterococcus durans, Enterococcus faecium, Enterococcus lactis, Enterococcus casseliflavus, Lactobacillus salivarius, Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus fermentum, Pediococcus pentosaceus and Leuconostoc mesenteroides. Of the total 60 isolates, 88 % harbored the ermB gene. The efflux gene msrA was identified in E. faecium, E. durans, E. lactis, E. casseliflavus, P. pentosaceus and L. fermentum. Further analysis of the msrA gene by sequencing suggested its homology to msrC. Resistance to tetracycline due to the genes tetM, tetW, tetO, tetK and tetL, alone or in combination, were identified in Lactobacillus species. The tetracycline efflux genes tetK and tetL occurred in P. pentosaceus and Enterococcus species. Since it appeared that LAB had acquired these genes, fermented foods may be a source of antibiotic resistance.
|
18. |
Vijay Simha B,
Sood SK,
Kumariya R,
Garsa AK,
( 2012 ) Simple and rapid purification of pediocin PA-1 from Pediococcus pentosaceous NCDC 273 suitable for industrial application. PMID : 22277956 : DOI : 10.1016/j.micres.2012.01.001 Abstract >>
The use of pediocins as food additives or drugs requires a simple and rapid method by which large quantities of homogeneous pediocin are produced at industrial level. Two centrifugation steps required during initial stages of purification i.e. separation of cells from fermentation broth and collection of precipitates after ammonium sulphate precipitation are the major bottlenecks for their large scale purification. In the present work, pediocin production by a new a dairy strain, Pediococcus pentosaceous NCDC 273 (identical to pediocin PA-1 at nucleotide sequence level), was found to be optimum at initial pH of 6.0 and 7.0 of basal MRS supplemented with 20 g/l of glucose or lactose at 20 and 24 h, respectively. Immobilization of cells through entrapment in alginate-xanthan gum gel beads with chitosan coating resulted in negligible cell release during fermentation. Thus, the cell free extract was directly collected through decantation, avoiding the need of centrifugation step at this stage. Subsequent ammonium sulphate precipitation at isoelectric point of pediocin PA-1 (8.85), using magnetic stirrer at high speed (approx. 1200 rpm), resulted in forceful deposition of precipitates on the wall of precipitation beaker allowing their collection using a spatula, avoiding centrifugation step at this stage also. Further purification using cation-exchange chromatography resulted in yield of 134.4% with more than 320 fold purification with the specific activity of 19��10? AU/mg. The collection of single peak of pediocin at 41.9min in RP-HPLC, overlapping with standard pediocin PA-1, resulted in yield of 1.15 �gg from 20 �gl of sample applied. The overlapping of RP-HPLC peak and SDS-PAGE band corresponding to 4.6 kDa, confirmed the purity and identity of pediocin 273 as pediocin PA-1.
|
19. |
( 1997 ) Molecular characterization of the replicon of the Pediococcus pentosaceus 43200 pediocin A plasmid pMD136. PMID : 9228759 : DOI : 10.1111/j.1574-6968.1997.tb12576.x Abstract >>
The pediocin A-encoding plasmid of Pediococcus pentosaceus 43200, pMD136, was characterized by restriction enzyme analysis. Analysis of its replicon was facilitated by the construction of a probe vector consisting of the Escherichia coli plasmid pSP72 and the cat gene from Staphylococcus aureus plasmid pC194. The replication region of pMD136 was localized on a 1.6-kb EcoRI/BglII fragment. Sequencing analysis revealed a non-coding region, repA, spanning the first 440 bp, followed by an open reading frame, repB, encoding a putative protein of 390 amino acids. The non-coding region contained two sets of 6-bp and two sets of 22-bp direct repeats and two sets of inverted repeats upstream of the open reading frame. Strong homology of the isolated replicon was found to theta-type replicons of Lactococcus lactis plasmids. Segregational stability assay suggested at least two regions as potentially involved in the stabilization of pMD136. The plasmid's strong homology to other theta-type replicons and its relatively high stability suggest that pMD136 belongs to the widespread family of theta-replication plasmids.
|
20. |
( 1994 ) Bacterial glutamate racemase has high sequence similarity with myoglobins and forms an equimolar inactive complex with hemin. PMID : 7937852 : DOI : 10.1073/pnas.91.21.10144 PMC : PMC44974 Abstract >>
Glutamate racemase (EC 5.1.1.3), an enzyme of microbial origin, shows significant sequence homology with mammalian myoglobins, in particular in the regions corresponding to the E and F helices, which constitute the heme binding pocket of myoglobins. Glutamate racemase binds tightly an equimolar amount of hemin, leading to loss of racemase activity. Although this enzyme shows homology with aspartate racemase, the latter does not bind hemin. The glutamate racemase gene of Pediococcus pentosaceus has a 795-nt open reading frame and encodes 265-amino acid residues, which form a monomeric protein (M(r) 29,000). Neither racemase has cofactors, but they contain essential cysteine residues [Yohda, M., Okada, H. & Kumagai, H. (1991) Biochim. Biophys. Acta 1089, 234-240].
|
21. |
( 1994 ) The Escherichia coli Dga (MurI) protein shares biological activity and structural domains with the Pediococcus pentosaceus glutamate racemase. PMID : 7904596 : DOI : 10.1128/jb.176.2.528-530.1994 PMC : PMC205080 Abstract >>
The Pediococcus pentosaceus glutamate racemase gene product complemented the D-glutamate auxotrophy of Escherichia coli WM335. Amino acid sequence analysis of the two proteins revealed 28% identity, primarily in six clusters scattered throughout the sequence. Further analyses indicated secondary structure similarities between the two proteins. These data support a recent report that the dga (murI) gene product is a glutamate racemase.
|
22. |
( 2013 ) Genotypic and phenotypic diversity of Pediococcus pentosaceus strains isolated from food matrices and characterisation of the penocin operon. PMID : 23444039 : DOI : 10.1007/s10482-013-9897-1 Abstract >>
Lactic acid bacteria (LAB) are widely used in the food industry. Pediococcus spp. belong to the LAB group and include several species that are essential for the quality of fermented food. Pediococcus pentosaceus is the species that is most frequently isolated from fermented food and beverages but its uncontrolled growth during food fermentation processes can contribute to undesired flavours. Hence, the characterisation of these bacteria at the strain level is of great importance for the quality of fermented products. Despite their importance, misidentification at the species level is common for members of the genus Pediococcus. To clarify the taxonomic relationships among strains, a multilocus sequencing approach was developed for the characterisation of a collection of 29 field strains, 1 type strain and 1 reference strain of P. pentosaceus isolated from food. These strains were also tested for several phenotypic properties of technological interest and for the production of bacteriocins. The chromosomal operon involved in the synthesis of the bacteriocin penocin was also investigated. The present study enabled a good genomic characterisation, identifying 17 sequence types, with an overview of phenotypic characteristics related to different technological abilities, and also provides a thorough characterisation of the operon involved in penocin production.
|
23. |
( 1998 ) Conservation of the major cold shock protein in lactic acid bacteria. PMID : 9767713 : Abstract >>
Primers designed from consensus regions of the major cold shock gene of different bacterial species were used in PCR amplification of Lactic Acid Bacteria (LAB). An appropriately-sized PCR product was obtained from Lactococcus lactis subsp. lactis LL43-1 and MG1363; Lactococcus lactis subsp. cremoris LC10-1, LC11-1, and LC12-1; Streptococcus thermophilus ST1-1; Enterococcus faecalis EF1-1; Lactobacillus acidophilus LA1-1; Lactobacillus helveticus LH1-1; Pediococcus pentosaceus PP1-1; and Bifidobacterium animalis BA1-1. The PCR products were cloned and sequenced. The deduced amino acid sequences displayed high sequence similarity with the major cold shock proteins of Escherichia coli and Bacillus subtilis and the human Y-box factor. The amino acid residues of the cold shock domain implicated in nucleic acid binding in several unrelated species were also highly conserved in the LAB strains. It is possible, therefore, that this protein in LAB may also act as a transcriptional enhancer to other cold shock genes and/or act as an RNA chaperone unwinding tightly folded RNA molecules.
|
24. |
( 1997 ) Detection and speciation of bacteria through PCR using universal major cold-shock protein primer oligomers. PMID : 9439003 : Abstract >>
The detection of bacteria using PCR is a well-established diagnostic technique. However, conventional PCR requires the use of DNA primer oligomers that are specific to the target organism and, as a consequence, a sample can only be tested for the presence of that specific target. A significant advantage would be to probe a sample for the presence of any bacteria, followed by identification. To achieve this it is necessary to identify a DNA sequence common to all bacteria. Here we demonstrate that such a sequence may be that encoding the major cold-shock proteins. Using two universal PCR primer oligomers from conserved regions of these gene homologues, we have amplified a 200 base-pair DNA sequence from more than 30 diverse Gram-positive and Gram-negative bacteria, including representatives from the genera Aeromonas, Bacillus, Citrobacter, Enterobacter, Enterococcus, Escherichia, Klebsiella, Lactobacillus, Lactococcus, Listeria, Pediococcus, Photobacterium, Proteus, Salmonella, Shigella, Staphylococcus, Streptococcus, and Yersinia. Sequence analysis of the amplified products confirmed a high level of DNA homology. Significantly, however, there are sufficient nucleotide variations to allow the unique allocation of each amplified sequence to its parental bacterium.
|
331, Shih-Pin Rd., Hsinchu 30062, Taiwan
Phone: +886-3-5223191
E-mail: bcrcweb@firdi.org.tw
web maintainance: +886-3-5223191 ext 593
Copyright © 2018.BCRC All rights reserved.The duplication or use of information and data such as texts or images or any linkage the website at the "bcrc.firdi.org.tw" is only permitted with the indication of the source or with prior approval by the BCRC(Bioresource Collection and Research Center).