Cloning, sequencing and expression of a novel glutamate decarboxylase gene from a newly isolated lactic acid bacterium, Lactobacillus brevis OPK-3

2007 ◽  
Vol 98 (2) ◽  
pp. 312-319 ◽  
Author(s):  
Ki-Bum Park ◽  
Suk-Heung Oh
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Glutamate Decarboxylase ◽  
Lactobacillus Brevis ◽  
Sequencing And Expression

scholarly journals GlnR Negatively Regulates Glutamate-Dependent Acid Resistance in Lactobacillus brevis

2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Luchan Gong ◽  
Cong Ren ◽  
Yan Xu
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Glutamate Decarboxylase ◽  
Wild Type Strain ◽  
Acid Resistance ◽  
Lactobacillus Brevis ◽  
Deletion Strain ◽  
Content Type ◽  
Gaba Production ◽  
Encoding Gene

ABSTRACT Lactic acid bacteria often encounter a variety of multiple stresses in their natural and industrial fermentation environments. The glutamate decarboxylase (GAD) system is one of the most important acid resistance systems in lactic acid bacteria. In this study, we demonstrated that GlnR, a nitrogen regulator in Gram-positive bacteria, directly modulated γ-aminobutyric acid (GABA) conversion from glutamate and was involved in glutamate-dependent acid resistance in Lactobacillus brevis. The glnR deletion strain (ΔglnR mutant) achieved a titer of 284.7 g/liter GABA, which is 9.8-fold higher than that of the wild-type strain. The cell survival of the glnR deletion strain was significantly higher than that of the wild-type strain under the condition of acid challenge and was positively correlated with initial glutamate concentration and GABA production. Quantitative reverse transcription-PCR assays demonstrated that GlnR inhibited the transcription of the glutamate decarboxylase-encoding gene (gadB), glutamate/GABA antiporter-encoding gene (gadC), glutamine synthetase-encoding gene (glnA), and specific transcriptional regulator-encoding gene (gadR) involved in gadCB operon regulation. Moreover, GABA production and glutamate-dependent acid resistance were absolutely abolished in the gadR glnR deletion strain. Electrophoretic mobility shift and DNase I footprinting assays revealed that GlnR directly bound to the 5′-untranslated regions of the gadR gene and gadCB operon, thus inhibiting their transcription. These results revealed a novel regulatory mechanism of GlnR on glutamate-dependent acid resistance in Lactobacillus. IMPORTANCE Free-living lactic acid bacteria often encounter acid stresses because of their organic acid-producing features. Several acid resistance mechanisms, such as the glutamate decarboxylase system, F1Fo-ATPase proton pump, and alkali production, are usually employed to relieve growth inhibition caused by acids. The glutamate decarboxylase system is vital for GAD-containing lactic acid bacteria to protect cells from DNA damage, enzyme inactivation, and product yield loss in acidic habitats. In this study, we found that a MerR-type regulator, GlnR, was involved in glutamate-dependent acid resistance by directly regulating the transcription of the gadR gene and gadCB operon, resulting in an inhibition of GABA conversion from glutamate in L. brevis. This study represents a novel mechanism for GlnR's regulation of glutamate-dependent acid resistance and also provides a simple and novel strategy to engineer Lactobacillus strains to elevate their acid resistance as well as GABA conversion from glutamate.

scholarly journals Gamma-aminobutyric acid fermentation with date residue by a lactic acid bacterium, Lactobacillus brevis

2018 ◽  
Vol 125 (3) ◽  
pp. 316-319 ◽  
Author(s):  
Momoko Hasegawa ◽  
Daisuke Yamane ◽  
Kouichi Funato ◽  
Atsushi Yoshida ◽  
Yoshihiro Sambongi
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Lactobacillus Brevis ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Acid Fermentation

Lactobacillus yonginensis sp. nov., a lactic acid bacterium with ginsenoside converting activity isolated from Kimchi

2013 ◽  
Vol 63 (Pt_9) ◽  
pp. 3274-3279 ◽  
Author(s):  
Eun-Ji Yi ◽  
Jung-Eun Yang ◽  
Jung Min Lee ◽  
YongJin Park ◽  
Sang-Yong Park ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Type Species ◽  
Gene Sequence ◽  
Sequence Similarity ◽  
Lactobacillus Brevis ◽  
Fermented Food ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type

A Gram-reaction-positive, non-motile, non-spore-forming, catalase-negative, facultatively anaerobic, rod-shaped, β-glucosidase-producing lactic acid bacterium, designated strain THK-V8T, was isolated from the Korean fermented food, Kimchi, and its taxonomic position was investigated by using a polyphasic approach. Strain THK-V8T was able to grow at 4–40 °C (optimum, 30 °C) and pH 4.0–7.0 (optimum, pH 6.0). Strain THK-V8T had the ability to transform ginsenoside Rb1 to Rd. On the basis of 16S rRNA gene sequence similarity data, strain THK-V8T was shown to belong to the genus Lactobacillus . Strain THK-V8T was related to Lactobacillus koreensis DCY50T (98.8 % sequence similarity), Lactobacillus parabrevis LMG 11984T (97.7 %), Lactobacillus senmaizukei L13T (97.5 %), Lactobacillus hammesii TMW1.1236T (97.3 %) and Lactobacillus brevis ATCC 14687T (97.2 %). Subsequently, sequence analysis of the RNA polymerase alpha subunit gene (rpoA) confirmed that strain THK-V8T showed a maximum rpoA gene sequence similarity value of 93 % with Lactobacillus brevis LMG 6906T. The G+C content of the genomic DNA was 47.8 mol%. The DNA–DNA hybridization values between strain THK-V8T and Lactobacillus parabrevis DCY50T and Lactobacillus parabrevis LMG 11984T were 46.1±4.9 % and 10.6±2.9 %, respectively. The major fatty acids were summed feature 7 (comprised of C19 : 0 cyclo ω10c/19ω6), C14 : 0, C16 : 0 and C18 : 1ω9c. The cell wall peptidoglycan was of the A4α l-Lys–d-Asp type. The phenotypic and molecular properties indicated that strain THK-V8T represents a novel species within the genus Lactobacillus , for which the name Lactobacillus yonginensis sp. nov. is proposed. The type strain is THK-V8T ( = KACC 16236T = JCM 18023T).

scholarly journals Taxonomic Structure and Monitoring of the Dominant Population of Lactic Acid Bacteria during Wheat Flour Sourdough Type I Propagation Using Lactobacillus sanfranciscensis Starters

2008 ◽  
Vol 75 (4) ◽  
pp. 1099-1109 ◽  
Author(s):  
Sonya Siragusa ◽  
Raffaella Di Cagno ◽  
Danilo Ercolini ◽  
Fabio Minervini ◽  
Marco Gobbetti ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactic Acid Bacterium ◽  
Wheat Flour ◽  
Gel Electrophoresis ◽  
Lactobacillus Brevis ◽  
Restriction Endonuclease Analysis ◽  
Taxonomic Structure ◽  
Type I ◽  
Lactobacillus Sanfranciscensis

ABSTRACTThe structure and stability of the dominant lactic acid bacterium population were assessed during wheat flour sourdough type I propagation by using singly nine strains ofLactobacillus sanfranciscensis. Under back-slopping propagation with wheat flour type 0 F114, cell numbers of presumptive lactic acid bacteria varied slightly between and within starters. As determined by randomly amplified polymorphic DNA-PCR and restriction endonuclease analysis-pulsed-field gel electrophoresis analyses, only three (LS8, LS14, and LS44) starters dominated throughout 10 days of propagation. The others progressively decreased to less than 3 log CFU g−1. Partial sequence analysis of the 16S rRNA andrecAgenes and PCR-denaturating gradient gel electrophoresis analysis using therpoBgene allowed identification ofWeissella confusa,Lactobacillus sanfranciscensis,Lactobacillus plantarum,Lactobacillus rossiae,Lactobacillus brevis,Lactococcus lactissubsp.lactis,Pediococcus pentosaceus, andLactobacillusspp. as the dominant species of the raw wheat flour. At the end of propagation, one autochthonous strain ofL. sanfranciscensiswas found in all the sourdoughs. Except forL. brevis, strains of the above species were variously found in the mature sourdoughs. Persistent starters were found in association with other biotypes ofL. sanfranciscensisand withW. confusaorL. plantarum. Sourdoughs were characterized for acidification, quotient of fermentation, free amino acids, and community-level catabolic profiles by USING Biolog 96-well Eco microplates. In particular, catabolic profiles of sourdoughs containing persistent starters behaved similarly and were clearly differentiated from the others. The three persistent starters were further used for the production of sourdoughs and propagated by using another wheat flour whose lactic acid bacterium population in part differed from the previous one. Also, in this case all three starter strains persisted during propagation.

scholarly journals Chromosomal Sequence of Lactobacillus brevis Oregon-R-modENCODE Strain BDGP6, a Lactic Acid Bacterium Isolated from the Gut of Drosophila melanogaster

2020 ◽  
Vol 9 (44) ◽  
Author(s):  
Kenneth H. Wan ◽  
Charles Yu ◽  
Soo Park ◽  
Ann S. Hammonds ◽  
Benjamin W. Booth ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Lactobacillus Brevis ◽  
Bacterial Chromosome ◽  
Microbial Interaction ◽  
Circular Dna ◽  
Content Type ◽  
Dna Molecule ◽  
Chromosomal Sequence

ABSTRACT Lactobacillus brevis Oregon-R-modENCODE strain BDGP6 was isolated from the gut of Drosophila melanogaster for functional host-microbial interaction studies. The bacterial chromosome is a single circular DNA molecule of 2,785,111 bp with a G+C content of 46%.

scholarly journals Structural and Functional Conversion of Molecular Chaperone ClpB from the Gram-Positive Halophilic Lactic Acid Bacterium Tetragenococcus halophilus Mediated by ATP and Stress

2006 ◽  
Vol 188 (23) ◽  
pp. 8070-8078 ◽  
Author(s):  
Shinya Sugimoto ◽  
Hiroyuki Yoshida ◽  
Yoshimitsu Mizunoe ◽  
Keigo Tsuruno ◽  
Jiro Nakayama ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Molecular Chaperone ◽  
Thermal Inactivation ◽  
Gel Filtration ◽  
Ring Structure ◽  
Stress Conditions ◽  
Gel Filtration Chromatography ◽  
Gram Positive ◽  
Tetragenococcus Halophilus

ABSTRACT In this study, we report the purification, initial structural characterization, and functional analysis of the molecular chaperone ClpB from the gram-positive, halophilic lactic acid bacterium Tetragenococcus halophilus. A recombinant T. halophilus ClpB (ClpB Tha ) was overexpressed in Escherichia coli and purified by affinity chromatography, hydroxyapatite chromatography, and gel filtration chromatography. As demonstrated by gel filtration chromatography, chemical cross-linking with glutaraldehyde, and electron microscopy, ClpB Tha forms a homohexameric single-ring structure in the presence of ATP under nonstress conditions. However, under stress conditions, such as high-temperature (>45°C) and high-salt concentrations (>1 M KCl), it dissociated into dimers and monomers, regardless of the presence of ATP. The hexameric ClpB Tha reactivated heat-aggregated proteins dependent upon the DnaK system from T. halophilus (KJE Tha ) and ATP. Interestingly, the mixture of dimer and monomer ClpB Tha , which was formed under stress conditions, protected substrate proteins from thermal inactivation and aggregation in a manner similar to those of general molecular chaperones. From these results, we hypothesize that ClpB Tha forms dimers and monomers to function as a holding chaperone under stress conditions, whereas it forms a hexamer ring to function as a disaggregating chaperone in cooperation with KJE Tha and ATP under poststress conditions.

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