Sequence analysis of pLBB1, a cryptic plasmid from Lactobacillus delbrueckii subsp. bulgaricus

2002 ◽  
Vol 48 (2) ◽  
pp. 105-112 ◽  
Author(s):  
M Andrea Azcárate-Peril ◽  
Raúl R Raya
Keyword(s):  
Sequence Analysis ◽  
Gc Content ◽  
Open Reading Frames ◽  
Lactobacillus Delbrueckii ◽  
Cryptic Plasmid ◽  
Lactobacillus Bulgaricus ◽  
Rolling Circle ◽  
Replication Region ◽  
Lactobacillus Lactis ◽  
Lactobacillus Delbrueckii Subsp

The first report of the complete nucleotide sequence of a cryptic plasmid from Lactobacillus delbrueckii subsp. bulgaricus (Lactobacillus bulgaricus) is presented. The plasmid pLBB1 consists of 6127 bp with a GC content of 44.8%. No ssDNA was detected by hybridization experiments, which is consistent with the notion that pLBB1 does not replicate by a rolling circle mechanism. A putative replication region of pLBB1 was cloned and found to be functional in Lactobacillus johnsonii and Lactococcus lactis. Plasmid pLBB1 showed significant DNA sequence identity with plasmid pLL1212 from Lactobacillus delbrueckii subsp. lactis (Lactobacillus lactis) CRL1212 (GenBank accession No. AF109691). Four open reading frames (ORFs) larger than 100 amino acids were identified. ORFA shared similarity with a putative primase–helicase system, and ORFB and ORFC exhibited limited identity with a mobilization protein and a transposase, respectively. Curing experiments did not allowed us to assign a function to the ORFs.Key words: Lactobacillus, cryptic plasmid, sequence analysis.

Transposition in Lactobacillus delbrueckii subsp. bulgaricus: identification of two thermosensitive replicons and two functional insertion sequences

Microbiology ◽  
2003 ◽  
Vol 149 (6) ◽  
pp. 1503-1511 ◽  
Author(s):  
Pascale Serror ◽  
Golnar Ilami ◽  
Hichem Chouayekh ◽  
S. Dusko Ehrlich ◽  
Emmanuelle Maguin
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Delbrueckii ◽  
Lactobacillus Bulgaricus ◽  
Insertion Sequences ◽  
Rolling Circle ◽  
Delivery Vector ◽  
Lactobacillus Delbrueckii Subsp

In this report, it is shown that the rolling circle replicon pG+host and the theta replicon pIP501 are thermosensitive in Lactobacillus delbrueckii subsp. bulgaricus (Lactobacillus bulgaricus). Using a pIP501 derivative as a delivery vector for six insertion sequences originating from lactic acid bacteria, it is shown that IS1223 and IS1201 transpose in L. bulgaricus.

scholarly journals Sequence Analysis of the Cryptic Plasmid pMG101 from Rhodopseudomonas palustris and Construction of Stable Cloning Vectors

2000 ◽  
Vol 66 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Masayuki Inui ◽  
Jung Hyeob Roh ◽  
Kenneth Zahn ◽  
Hideaki Yukawa
Keyword(s):  
Plasmid Stability ◽  
Rhodopseudomonas Palustris ◽  
Open Reading Frames ◽  
Cryptic Plasmid ◽  
Deletion Mapping ◽  
Cloning Vectors ◽  
Par Proteins ◽  
Gene Coding ◽  
Rep Proteins ◽  
Replication Region

ABSTRACTA 15-kb cryptic plasmid was obtained from a natural isolate ofRhodopseudomonas palustris. The plasmid, designated pMG101, was able to replicate inR. palustrisand in closely related strains ofBradyrhizobium japonicumand phototrophicBradyrhizobiumspecies. However, it was unable to replicate in the purple nonsulfur bacteriumRhodobacter sphaeroidesand inRhizobiumspecies. The replication region of pMG101 was localized to a 3.0-kbSalI-XhoI fragment, and this fragment was stably maintained inR. palustrisfor over 100 generations in the absence of selection. The complete nucleotide sequence of this fragment revealed two open reading frames (ORFs), ORF1 and ORF2. The deduced amino acid sequence of ORF1 is similar to sequences of Par proteins, which mediate plasmid stability from certain plasmids, while ORF2 was identified as a putativerepgene, coding for an initiator of plasmid replication, based on homology with the Rep proteins of several other plasmids. The function of these sequences was studied by deletion mapping and gene disruptions of ORF1 and ORF2. pMG101-basedEscherichia coli-R. palustrisshuttle cloning vectors pMG103 and pMG105 were constructed and were stably maintained inR. palustrisgrowing under nonselective conditions. The ability of plasmid pMG101 to replicate inR. palustrisand its close phylogenetic relatives should enable broad application of these vectors within this group of α-proteobacteria.

scholarly journals Isolation and Characterization of a Rolling-Circle-Type Plasmid from Rhodococcus erythropolis and Application of the Plasmid to Multiple-Recombinant-Protein Expression

2004 ◽  
Vol 70 (9) ◽  
pp. 5557-5568 ◽  
Author(s):  
Nobutaka Nakashima ◽  
Tomohiro Tamura
Keyword(s):  
Recombinant Protein Expression ◽  
Rhodococcus Erythropolis ◽  
Open Reading Frames ◽  
Cryptic Plasmid ◽  
Expression Vectors ◽  
Rolling Circle Replication ◽  
Single Stranded Dna ◽  
Rolling Circle ◽  
Isolation And Characterization ◽  
Double Stranded Dna

ABSTRACT We isolated, sequenced, and characterized the cryptic plasmid pRE8424 from Rhodococcus erythropolis DSM8424. Plasmid pRE8424 is a 5,987-bp circular plasmid; it carries six open reading frames and also contains cis-acting elements, specifically a single-stranded origin and a double-stranded origin, which are characteristic of rolling-circle-replication plasmids. Experiments with pRE8424 derivatives carrying a mutated single-stranded origin sequence showed that single-stranded DNA intermediates accumulated in the cells because of inefficient conversion from single-stranded DNA to double-stranded DNA. This result indicates that pRE8424 belongs to the pIJ101/pJV1 family of rolling-circle-replication plasmids. Expression vectors that are functional in several Rhodococcus species were constructed by use of the replication origin from pRE8424. We previously reported a cryptic plasmid, pRE2895, from R. erythropolis, which may replicate by a θ-type mechanism, like ColE2 plasmids. The new expression vectors originating from pRE8424 were compatible with those derived from pRE2895. Coexpression experiments with these compatible expression vectors indicated that the plasmids are suitable for the simultaneous expression of multiple recombinant proteins.

Production and monomer composition of exopolysaccharides by yogurt starter cultures

2000 ◽  
Vol 46 (12) ◽  
pp. 1123-1127 ◽  
Author(s):  
Ginka I Frengova ◽  
Emilina D Simova ◽  
Dora M Beshkova ◽  
Zhelyasko I Simov
Keyword(s):  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Lactobacillus Bulgaricus ◽  
Streptococcus Salivarius ◽  
Monomer Composition ◽  
Monomer Structure ◽  
Production Activity ◽  
Thermophilic Streptococci ◽  
Lactobacillus Delbrueckii Subsp

As components of starter cultures for Bulgarian yogurt, Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus revealed extensive exopolysaccharide (EPS) production activity when cultivated in whole cow's milk. The polymer-forming activity of thermophilic streptococci was lower (230-270 mg EPS/L) than that of the lactobacilli (400-540 mg EPS/L). Mixed cultures stimulated EPS production in yogurt manufacture, and a maximum concentration of 720-860 mg EPS/L was recorded after full coagulation of milk. The monomer structure of the exopolysaccharides formed by the yogurt starter cultures principally consists of galactose and glucose (1:1), with small amounts of xylose, arabinose, and/or mannose.Key words: Streptococcus thermophilus, Lactobacillus bulgaricus, starter cultures, yogurt, exopolysaccharides.

scholarly journals Complete Nucleotide Sequence of the LE1 Prophage from the Spirochete Leptospira biflexa and Characterization of Its Replication and Partition Functions

2005 ◽  
Vol 187 (12) ◽  
pp. 3931-3940 ◽  
Author(s):  
Pascale Bourhy ◽  
Lionel Frangeul ◽  
Elisabeth Couvé ◽  
Philippe Glaser ◽  
Isabelle Saint Girons ◽  
...  
Keyword(s):  
Genetic Manipulation ◽  
Plasmid Stability ◽  
Shuttle Vector ◽  
Gc Content ◽  
Open Reading Frames ◽  
Partition Functions ◽  
Shuttle Vectors ◽  
Repressor Proteins ◽  
Replication Region

ABSTRACT The first and, to date, only extrachromosomal circular replicon identified in the spirochete Leptospira is the LE1 prophage from Leptospira biflexa. The 74-kb LE1 genome has a GC content of 36%, which is similar to the GC content of Leptospira spp. Most of the 79 predicted open reading frames (ORFs) showed no similarities to known ORFs. However 21 ORFs appeared to be organized in clusters that could code for head and tail structural proteins and immunity repressor proteins. In addition, the pattern of gene expression showed that several LE1 genes are expressed specifically either in LE1 prophage or in L. biflexa late after infection. Since the LE1 prophage replicates autonomously as a circular replicon in L. biflexa, we were able to engineer an L. biflexa-Escherichia coli shuttle vector from a 5.3-kb DNA fragment of LE1 (Saint Girons et al., J. Bacteriol. 182:5700-5705, 2000), opening this genus to genetic manipulation. In this study, base compositional asymmetry confirms the location of the LE1 replication region and suggests that LE1 replicates via a bidirectional Θ-like replication mechanism from this unique origin. By subcloning experiments, the replication region can be narrowed down to a 1-kb region. This minimal replication region consists of a rep encoding a protein of 180 amino acids. Upstream from rep, putative partitioning genes, called parA and parB, were found to be similar to the par loci in Borrelia plasmids. A significant increase of plasmid stability in L. biflexa can be seen only when both parA and parB are present. These results enable the construction of new shuttle vectors for studying the genetics of Leptospira spp. This study will also contribute to a better knowledge of phages unrelated to lambdoid phages.

Sign in / Sign up

Export Citation Format

Share Document