scholarly journals Proteome Analyses of Heme-Dependent Respiration in Lactococcus lactis: Involvement of the Proteolytic System

2004 ◽  
Vol 186 (6) ◽  
pp. 1648-1657 ◽  
Author(s):  
Karin Vido ◽  
Dominique le Bars ◽  
Michel-Yves Mistou ◽  
Patricia Anglade ◽  
Alexandra Gruss ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Growth Conditions ◽  
Transcriptional Analysis ◽  
Rich Medium ◽  
Triple Mutant ◽  
Proteolytic System ◽  
Sugar Fermentation ◽  
Absolute Requirement ◽  
Static Conditions ◽  
Respiratory Conditions

ABSTRACT Sugar fermentation was long considered the sole means of energy metabolism available to lactic acid bacteria. We recently showed that metabolism of Lactococcus lactis shifts progressively from fermentation to respiration during growth when oxygen and heme are available. To provide insights into this phenomenon, we compared the proteomic profiles of L. lactis under fermentative and respiratory growth conditions in rich medium. We identified 21 proteins whose levels differed significantly between these conditions. Two major groups of proteins were distinguished, one involved in carbon metabolism and the second in nitrogen metabolism. Unexpectedly, enzymes of the proteolytic system (PepO1 and PepC) which are repressed in rich medium in fermentation growth were induced under respiratory conditions despite the availability of free amino acids. A triple mutant (dtpT dtpP oppA) deficient in oligopeptide transport displayed normal respiration, showing that increased proteolytic activity is not an absolute requirement for respiratory metabolism. Transcriptional analysis confirmed that pepO1 is induced under respiration-permissive conditions. This induction was independent of CodY, the major regulator of proteolytic functions in L. lactis. We also observed that pepO1 induction is redox sensitive. In a codY mutant, pepO1 expression was increased twofold in aeration and eightfold in respiration-permissive conditions compared to static conditions. These observations suggest that new regulators activate proteolysis in L. lactis, which help to maintain the energetic needs of L. lactis during respiration.

scholarly journals Novel Food-Grade Plasmid Vector Based on Melibiose Fermentation for the Genetic Engineering of Lactococcus lactis

2002 ◽  
Vol 68 (12) ◽  
pp. 6152-6161 ◽  
Author(s):  
Isabelle Boucher ◽  
Marc Parrot ◽  
Hélène Gaudreau ◽  
Claude P. Champagne ◽  
Christian Vadeboncoeur ◽  
...  
Keyword(s):  
Genetic Engineering ◽  
Lactococcus Lactis ◽  
Defense Mechanism ◽  
Growth Parameters ◽  
Carbon Sources ◽  
Plasmid Vector ◽  
Transcriptional Analysis ◽  
Gene Encoding ◽  
Food Grade ◽  
Sugar Fermentation

ABSTRACT The α-galactosidase gene (aga) and a gene coding for a putative transcriptional regulator from the LacI/GalR family (galR) of Lactococcus raffinolactis ATCC 43920 were cloned and sequenced. When transferred into Lactococcus lactis and Pediococcus acidilactici strains, aga modified the sugar fermentation profile of the strains from melibiose negative (Mel−) to melibiose positive (Mel+). Analysis of galA mutants of L. lactis subsp. cremoris MG1363 indicated that the putative galactose permease GalA is also needed to obtain the Mel+ phenotype. Consequently, GalA may also transport melibiose into this strain. We demonstrated that when aga was associated with the theta-type replicon of a natural L. lactis plasmid, it constituted the selectable marker of a cloning vector named pRAF800. Transcriptional analysis by reverse transcriptase PCR suggests that this vector is also suitable for gene expression. The α-galactosidase activity conferred by pRAF800 was monitored in an industrial strain grown in the presence of various carbon sources. The results indicated that the enzymatic activity was induced by galactose and melibiose, but not by glucose or lactose. The gene encoding the phage defense mechanism, AbiQ, was cloned into pRAF800, and the resulting clone (pRAF803) was transferred into an industrial L. lactis strain that became highly phage resistant. The measurements of various growth parameters indicated that cells were not affected by the presence of pRAF803. Moreover, the plasmid was highly stable in this strain even under starter production conditions. The L. raffinolactis aga gene represents the basis of a novel and convenient food-grade molecular tool for the genetic engineering of lactic acid bacteria.

Genetic and transcriptional analysis of a novel plasmid-encoded copper resistance operon from Lactococcus lactis

Gene ◽  
2002 ◽  
Vol 297 (1-2) ◽  
pp. 241-247 ◽  
Author(s):  
Chun-Qiang Liu ◽  
Pilaiwan Charoechai ◽  
Nongpanga Khunajakr ◽  
Yi-Mo Deng ◽  
Widodo ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Copper Resistance ◽  
Transcriptional Analysis

scholarly journals Antimicrobial Activity of Lactococcus lactis subsp. lactis Isolated from a Stranded Cuvier’s Beaked Whale (Ziphius cavirostris) against Gram-Positive and -Negative Bacteria

2021 ◽  
Vol 9 (2) ◽  
pp. 243
Author(s):  
Akihiko Suzuki ◽  
Miwa Suzuki
Keyword(s):  
Lactococcus Lactis ◽  
Marine Organism ◽  
Growth Conditions ◽  
Gas Production ◽  
Beaked Whale ◽  
Carbohydrate Utilization ◽  
Nisin Z ◽  
Ziphius Cavirostris ◽  
Cuvier’S Beaked Whale ◽  
Subtilis Subsp

In the present study, we isolated and characterized Lactococcus lactis (L. lactis) subsp. lactis from a female Cuvier’s beaked whale (Ziphius cavirostris) stranded in Shizuoka, Japan. Only five isolates (CBW1-5), grown on Lactobacilli de Man Rogosa Sharpe (MRS) agar plates prepared using 50% artificial seawater, were positive in L. lactis species-specific primer PCR. Their 16S rRNA sequences were highly similar to those of L. lactis subsp. lactis JCM 5805T. The Gram reaction, motility, gas production from glucose, catalase production, and growth conditions were consistent with those of the type strain. Additionally, carbohydrate utilization of the strains was consistent with previously reported marine organism-derived strains. The pH-neutralized cell-free culture supernatant of strain CBW2 inhibited the growth of Bacillus subtilis subsp. subtilis ATCC 6051 and Vibrio alginolyticus ATCC 17749, whereas protease treatment eliminated or diminished its inhibitory activity. The strain possesses a precursor of the nisin structural gene (nisA), which showed 100% homology with nisin Z, and nisin biosynthesis-related genes (nisB, nisC, nisT, nisP, nisF, nisI, and nisRK), suggesting that the strain produces a nisin-like substance. This study provides fundamental information on whale-derived L. lactis subsp. lactis which may be useful for reducing the carriage of B. subtilis subsp. subtilis and V. alginolyticus.

scholarly journals Effect of growth conditions on glutathione accumulation, gshR gene expression and resistance to the lyophilization process in Lactococcus lactis LVA. 2

2014 ◽  
Vol 8 (30) ◽  
pp. 2874-2880
Author(s):  
dos Santos Leandro Eliana ◽  
Kunrath Lima Graciela ◽  
Fernandes de Carvalho Antnio ◽  
Alfenas Zerbini Poliane ◽  
Gomes Pereira Odilon ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lactococcus Lactis ◽  
Growth Conditions

scholarly journals OPTIMIZATION OF BACTERIOCIN PRODUCTION BY Lactococcus lactis ssp. lactis CN1.10a ORIGIN FROM RUSIPS

2014 ◽  
Vol 9 (3) ◽  
pp. 97
Author(s):  
Ninoek Indriati ◽  
Arifah Kusmarwati ◽  
Irma Hermana
Keyword(s):  
Lactococcus Lactis ◽  
Growth Curve ◽  
Growth Conditions ◽  
Relative Activity ◽  
Bacteriocin Production ◽  
Bacteriocin Activity ◽  
Carbohydrate Source ◽  
Fermented Fish ◽  
Producer Cell

Previous study of bacteriocin production on laboratory scale (100 mL) that used MRS broth medium produced unstable activity of bacteriocin. Therefore, this study aims to determine the optimum growth conditions and media for production of bacteriocin. Bacteria used in this research was a lactic acid bacteria (LAB) Lactococcus lactis ssp. lactis CN1.10a  isolated from rusip, a traditional Bangkanese fermented fish product.The bacteria was first cultivated for subsequent use of bacteriocins production on intermediate scale (2L). Followed by the optimization of temperature, pH and medium for the bacteriocin production, determination of cell growth curve, bacteriocin production curve, bacteriocin activity on that scale, and also stability of bacteriocin during storage.The results showed that the optimum temperature and pH for the growth of producer cell were 28°C and pH 6. The greatest activity of bacteriocin was produced on CM medium (1% sucrose, 0,45% peptone, 1% yeast extract, 2,84% KH2PO4, 0,2% NaCl and 0,02% MgSO4.7H20) in addition of sucrose as carbohydrate source. Based on the growth curve performedon CM medium with KH2PO4, the L. Lactis ssp lactis CN1.10a was relatively stable up to 48 hours. Bacteriocin produced by the cell was  8000 AU/mlat24th hour.Bacteriocin  was relatively stable when stored at -20°C for 1month with a relative activity of 69,4%.

scholarly journals Genome Sequences of Lactococcus lactis MG1363 (Revised) and NZ9000 and Comparative Physiological Studies

2010 ◽  
Vol 192 (21) ◽  
pp. 5806-5812 ◽  
Author(s):  
Daniel M. Linares ◽  
Jan Kok ◽  
Bert Poolman
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Glucose Uptake ◽  
Lactococcus Lactis ◽  
Point Mutations ◽  
Genome Sequences ◽  
Sugar Fermentation ◽  
Sequencing Strategy ◽  
Physiological Studies ◽  
Transcriptomic Studies

ABSTRACT Lactococcus lactis NZ9000 and its parent MG1363 are the most commonly used lactic acid bacteria for expression and physiological studies. We noted unexpected but significant differences in the growth behaviors of both strains. We sequenced the entire genomes of the original NZ9000 and MG1363 strains using an ultradeep sequencing strategy. The analysis of the L. lactis NZ9000 genome yielded 79 differences, mostly point mutations, with the annotated genome sequence of L. lactis MG1363. Resequencing of the MG1363 strain revealed that 73 out of the 79 differences were due to errors in the published sequence. Comparative transcriptomic studies revealed several differences in the regulation of genes involved in sugar fermentation, which can be explained by two specific mutations in a region of the ptcC promoter with a key role in the regulation of cellobiose and glucose uptake.

scholarly journals Activation of the Diacetyl/Acetoin Pathway in Lactococcus lactis subsp. lactis bv. diacetylactis CRL264 by Acidic Growth

2008 ◽  
Vol 74 (7) ◽  
pp. 1988-1996 ◽  
Author(s):  
Nieves García-Quintáns ◽  
Guillermo Repizo ◽  
Mauricio Martín ◽  
Christian Magni ◽  
Paloma López
Keyword(s):  
Lactococcus Lactis ◽  
Biosynthetic Pathway ◽  
Growth Conditions ◽  
Aroma Compounds ◽  
Starter Cultures ◽  
Pcr Analysis ◽  
Transcriptional Level ◽  
Ph Homeostasis ◽  
Acid Growth ◽  
The Impact

ABSTRACT Lactococcus lactis subsp. lactis bv. diacetylactis strains are aroma-producing organisms used in starter cultures for the elaboration of dairy products. This species is essentially a fermentative microorganism, which cometabolizes glucose and citrate to yield aroma compounds through the diacetyl/acetoin biosynthetic pathway. Our previous results have shown that under acidic growth Lactococcus bv. diacetylactis CRL264 expresses coordinately the genes responsible for citrate transport and its conversion into pyruvate. In the present work the impact of acidic growth on glucose, citrate, and pyruvate metabolism of Lactococcus bv. diacetylactis CRL264 has been investigated by proteomic analysis. The results indicated that acid growth triggers the conversion of citrate, but not glucose, into α-acetolactate via pyruvate. Moreover, they showed that low pH has no influence on levels of lactate dehydrogenase and pyruvate dehydrogenase. Therefore, the influence of external pH on regulation of the diacetyl/acetoin biosynthetic pathway in Lactococcus bv. diacetylactis CRL264 has been analyzed at the transcriptional level. Expression of the als, aldB, aldC, and butBA genes encoding the enzymes involved in conversion of pyruvate into aroma compounds has been investigated by primer extension, reverse transcription-PCR analysis, and transcriptional fusions. The results support that this biosynthetic pathway is induced at the transcriptional level by acidic growth conditions, presumably contributing to lactococcal pH homeostasis by synthesis of neutral compounds and by decreasing levels of pyruvate.

scholarly journals The Riboflavin Transporter RibU in Lactococcus lactis: Molecular Characterization of Gene Expression and the Transport Mechanism

2006 ◽  
Vol 188 (8) ◽  
pp. 2752-2760 ◽  
Author(s):  
Catherine M. Burgess ◽  
Dirk Jan Slotboom ◽  
Eric R. Geertsma ◽  
Ria H. Duurkens ◽  
Bert Poolman ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Transcriptional Control ◽  
Transport Protein ◽  
Transcriptional Analysis ◽  
Start Codon ◽  
Flavin Mononucleotide ◽  
Membrane Spanning ◽  
Riboflavin Transport ◽  
Classification Database

ABSTRACT This study describes the characterization of the riboflavin transport protein RibU in the lactic acid bacterium Lactococcus lactis subsp. cremoris NZ9000. RibU is predicted to contain five membrane-spanning segments and is a member of a novel transport protein family, not described in the Transport Classification Database. Transcriptional analysis revealed that ribU transcription is downregulated in response to riboflavin and flavin mononucleotide (FMN), presumably by means of the structurally conserved RFN (riboflavin) element located between the transcription start site and the start codon. An L. lactis strain carrying a mutated ribU gene exhibits altered transcriptional control of the riboflavin biosynthesis operon ribGBAH in response to riboflavin and FMN and does not consume riboflavin from its growth medium. Furthermore, it was shown that radiolabeled riboflavin is not taken up by the ribU mutant strain, in contrast to the wild-type strain, directly demonstrating the involvement of RibU in riboflavin uptake. FMN and the toxic riboflavin analogue roseoflavin were shown to inhibit riboflavin uptake and are likely to be RibU substrates. FMN transport by RibU is consistent with the observed transcriptional regulation of the ribGBAH operon by external FMN. The presented transport data are consistent with a uniport mechanism for riboflavin translocation and provide the first detailed molecular and functional analysis of a bacterial protein involved in riboflavin transport.

scholarly journals The Posttranslocational Chaperone Lipoprotein PrsA Is Involved in both Glycopeptide and Oxacillin Resistance in Staphylococcus aureus

2012 ◽  
Vol 56 (7) ◽  
pp. 3629-3640 ◽  
Author(s):  
Ambre Jousselin ◽  
Adriana Renzoni ◽  
Diego O. Andrey ◽  
Antoinette Monod ◽  
Daniel P. Lew ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Wall Stress ◽  
Growth Conditions ◽  
Transcriptional Analysis ◽  
Pharmacological Intervention ◽  
Content Type ◽  
Cell Wall Stress ◽  
Oxacillin Resistance ◽  
Mrsa Strains

ABSTRACTUnderstanding in detail the factors which permitStaphylococcus aureusto counteract cell wall-active antibiotics is a prerequisite to elaborating effective strategies to prolong the usefulness of these drugs and define new targets for pharmacological intervention. Methicillin-resistantS. aureus(MRSA) strains are major pathogens of hospital-acquired and community-acquired infections and are most often treated with glycopeptides (vancomycin and teicoplanin) because of their resistance to most penicillins and a limited arsenal of clinically proven alternatives. In this study, we examined PrsA, a lipid-anchored protein of the parvulin PPIase family (peptidyl-prolylcis/transisomerase) found ubiquitously in all Gram-positive species, in which it assists posttranslocational folding at the outer surface of the cytoplasmic membrane. We show by both genetic and biochemical assays thatprsAis directly regulated by the VraRS two-component sentinel system of cell wall stress. Disruption ofprsAis tolerated byS. aureus, and its loss results in no detectable overt macroscopic changes in cell wall architecture or growth rate under nonstressed growth conditions. Disruption ofprsAleads, however, to notable alterations in the sensitivity to glycopeptides and dramatically decreases the resistance of COL (MRSA) to oxacillin. Quantitative transcriptional analysis reveals thatprsAandvraRare coordinately upregulated in a panel of stable laboratory and clinical glycopeptide-intermediateS. aureus(GISA) strains compared to their susceptible parents. Collectively, our results point to a role forprsAas a facultative facilitator of protein secretion or extracellular folding and provide a framework for understanding whyprsAis a key element of the VraRS-mediated cell wall stress response.

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