Role of the Mn-Catalase in Aerobic Growth of Lactobacillus plantarum ATCC 14431

Lactobacilli are Gram-positive aerotolerant organisms that comprise the largest genus of Lactic Acid Bacteria (LAB). Most lactobacilli are devoid of the antioxidant enzymes, superoxide dismutases, and catalases, required for protection against superoxide radicals and hydrogen peroxide (H2O2), respectively. However, some lactobacilli can accumulate millimolar concentrations of intracellular manganese and spare the need for superoxide dismutase, while others possess non-heme catalases. L. plantarum is associated with plant materials and plays an important role in fermented foods and gut microbiomes. Therefore, understanding the effects of the environment on the growth and survival of this organism is essential for its success in relevant industrial applications. In this report, we investigated the physiological role of Mn-catalase (MnKat) in Lactobacillus plantarum ATCC 14431. To this end, we compared the physiological and morphological properties of a ΔMnkat mutant strain and its isogenic parental strain L. plantarum ATCC 14431. Our data showed that the MnKat is critical for the growth of L. plantarum ATCC 14431 in the presence of oxygen and resistance to H2O2. The aerobic growth of the mutant in presence or absence of H2O2 was improved in the Mn-rich medium (APT) as compared to the growth in MRS medium. Furthermore, under aerobic conditions the mutant strain possessed atypical cellular morphology (i.e., shorter, and fatter). In conclusion, the MnKat of L. plantarum ATCC 14431 is important for aerobic growth, protection against H2O2, and maintenance of the rod-shaped cell morphology under aerobic conditions.

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Anaerobic and Aerobic Degradation of Cyanophycin by the Denitrifying Bacterium Pseudomonas alcaligenes Strain DIP1 and Role of Three Other Coisolates in a Mixed Bacterial Consortium

Applied and Environmental Microbiology ◽

10.1128/aem.02575-07 ◽

2008 ◽

Vol 74 (11) ◽

pp. 3434-3443 ◽

Cited By ~ 17

Author(s):

Ahmed Sallam ◽

Alexander Steinbüchel

Keyword(s):

High Performance ◽

Physiological Role ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Strictly Anaerobic ◽

Bacterial Strains ◽

Direct Role ◽

Aerobic Conditions ◽

Pseudomonas Alcaligenes

ABSTRACT Four bacterial strains were isolated from a cyanophycin granule polypeptide (CGP)-degrading anaerobic consortium, identified by 16S rRNA gene sequencing, and assigned to species of the genera Pseudomonas, Enterococcus, Clostridium, and Paenibacillus. The consortium member responsible for CGP degradation was assigned as Pseudomonas alcaligenes strain DIP1. The growth of and CGP degradation by strain DIP1 under anaerobic conditions were enhanced but not dependent on the presence of nitrate as an electron acceptor. CGP was hydrolyzed to its constituting β-Asp-Arg dipeptides, which were then completely utilized within 25 and 4 days under anaerobic and aerobic conditions, respectively. The end products of CGP degradation by strain DIP1 were alanine, succinate, and ornithine as determined by high-performance liquid chromatography analysis. The facultative anaerobic Enterococcus casseliflavus strain ELS3 and the strictly anaerobic Clostridium sulfidogenes strain SGB2 were coisolates and utilized the β-linked isodipeptides from the common pool available to the mixed consortium, while the fourth isolate, Paenibacillus odorifer strain PNF4, did not play a direct role in the biodegradation of CGP. Several syntrophic interactions affecting CGP degradation, such as substrate utilization, the reduction of electron acceptors, and aeration, were elucidated. This study demonstrates the first investigation of CGP degradation under both anaerobic and aerobic conditions by one bacterial strain, with regard to the physiological role of other bacteria in a mixed consortium.

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Disruption of the alsSD operon of Enterococcus faecalis impairs growth on pyruvate at low pH

Microbiology ◽

10.1099/mic.0.047662-0 ◽

2011 ◽

Vol 157 (9) ◽

pp. 2708-2719 ◽

Cited By ~ 18

Author(s):

Guillermo D. Repizo ◽

Pablo Mortera ◽

Christian Magni

Keyword(s):

Enterococcus Faecalis ◽

Mutant Strain ◽

Biosynthetic Pathway ◽

Growth Parameters ◽

Physiological Role ◽

Acetolactate Synthase ◽

Low Ph ◽

Transcriptional Analysis ◽

Initial Ph

Diacetyl and acetoin are pyruvate-derived metabolites excreted by many micro-organisms, and are important in their physiology. Although generation of these four-carbon (C4) compounds in Enterococcus faecalis is a well-documented phenotype, little is known about the gene regulation of their biosynthetic pathway and the physiological role of the pathway in this bacterium. In this work, we identified the genes involved in C4 compound biosynthesis in Ent. faecalis and report their transcriptional analysis. These genes are part of the alsSD bicistronic operon, which encodes α-acetolactate synthase (AlsS) and α-acetolactate decarboxylase (AlsD). Our studies showed that alsSD operon transcription levels are maximal during the exponential phase of growth, decreasing thereafter. Furthermore, we found that this transcription is enhanced upon addition of pyruvate to the growth medium. In order to study the functional role of the alsSD operon, an isogenic alsSD mutant strain was constructed. This strain lost its capacity to generate C4 compounds, confirming the role of alsSD genes in this metabolic pathway. In contrast to the wild-type strain, the alsSD-deficient strain was unable to grow in LB medium supplemented with pyruvate at an initial pH of 4.5. This dramatic reduction in growth parameters for the mutant strain was simultaneously accompanied by the inability to alkalinize the internal and external medium under these conditions. In sum, these results suggest that the decarboxylation reactions related to the C4 biosynthetic pathway give enterococcal cells a competitive advantage during pyruvate metabolism at low pH.

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Role of luxS in Stress Tolerance and Adhesion Ability in Lactobacillus plantarum KLDS1.0391

BioMed Research International ◽

10.1155/2018/4506829 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 8

Author(s):

Fang-Fang Jia ◽

Hui-Qi Zheng ◽

Si-Rui Sun ◽

Xue-Hui Pang ◽

Yu Liang ◽

...

Keyword(s):

Lactobacillus Plantarum ◽

Mutant Strain ◽

Type Strain ◽

Wild Type Strain ◽

Survival Rates ◽

High Survival ◽

Intestinal Epithelial ◽

Wild Type ◽

Adhesion Ability

Lactobacillus plantarum, a probiotic, has a high survival rate and high colonization ability in the gastrointestinal tract. Tolerance to the gastrointestinal environment and adhesion to intestinal epithelial cells by some Lactobacillus species (excluding L. plantarum) are related to luxS/AI-2. Here, the role of luxS in tolerance to simulated digestive juice (SDJ) and adhesion to Caco-2 cells by L. plantarum KLDS1.0391 (hereafter, KLDS1.0391) was investigated. The KLDS1.0391 luxS mutant strain was constructed by homologous recombination. When luxS was deleted, acid and bile salt tolerance and survival rates in SDJ significantly decreased (p<0.05 for all). The ability of the luxS deletion strain to adhere to Caco-2 cells was markedly lower than that of the wild-type strain (p<0.05). The ability of the luxS mutant strain to adhere (competition, exclusion, and displacement) to Escherichia coli ATCC 25922 was significantly lower than that of the wild-type strain (p<0.05 for all). A significant decrease was noted only in the exclusion adhesion inhibition of the luxS mutant strain to Salmonella typhimurium ATCC 14028 (p<0.05). These results indicate that the luxS gene plays an important role in the gastrointestinal environment tolerance and adhesion ability of KLDS1.0391.

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Major Role of NAD-Dependent Lactate Dehydrogenases in Aerobic Lactate Utilization in Lactobacillus plantarum during Early Stationary Phase

Journal of Bacteriology ◽

10.1128/jb.186.19.6661-6666.2004 ◽

2004 ◽

Vol 186 (19) ◽

pp. 6661-6666 ◽

Cited By ~ 51

Author(s):

Philippe Goffin ◽

Frédérique Lorquet ◽

Michiel Kleerebezem ◽

Pascal Hols

Keyword(s):

Lactate Dehydrogenase ◽

Stationary Phase ◽

Lactobacillus Plantarum ◽

Aerobic Growth ◽

Early Stationary Phase ◽

Double Knockout ◽

Knockout Mutants ◽

Lactate Utilization ◽

Lactate Dehydrogenases

ABSTRACT NAD-independent lactate dehydrogenases are commonly thought to be responsible for lactate utilization during the stationary phase of aerobic growth in Lactobacillus plantarum. To substantiate this view, we constructed single and double knockout mutants for the corresponding genes, loxD and loxL. Lactate-to-acetate conversion was not impaired in these strains, while it was completely blocked in mutants deficient in NAD-dependent lactate dehydrogenase activities, encoded by the ldhD and ldhL genes. We conclude that NAD-dependent but not NAD-independent lactate dehydrogenases are involved in this process.

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Interacting Regulatory Circuits Involved in Orderly Control of Photosynthesis Gene Expression in Rhodobacter sphaeroides 2.4.1

Journal of Bacteriology ◽

10.1128/jb.182.11.3081-3087.2000 ◽

2000 ◽

Vol 182 (11) ◽

pp. 3081-3087 ◽

Cited By ~ 51

Author(s):

Jeong-Il Oh ◽

Jesus M. Eraso ◽

Samuel Kaplan

Keyword(s):

Gene Expression ◽

Complex Formation ◽

Mutant Strain ◽

Rhodobacter Sphaeroides ◽

Photosynthetic Apparatus ◽

Aerobic Conditions ◽

Multiple Loci ◽

Regulatory Circuits ◽

Spectral Complex

ABSTRACT FnrL, the homolog of the global anaerobic regulator Fnr, is required for the induction of the photosynthetic apparatus inRhodobacter sphaeroides 2.4.1. Thus, the precise role of FnrL in photosynthesis (PS) gene expression and its interaction(s) with other regulators of PS gene expression are of considerable importance to our understanding of the regulatory circuitry governing spectral complex formation. Using a CcoP and FnrL double mutant strain, we obtained results which suggested that FnrL is not involved in the transduction of the inhibitory signal, by which PS gene expression is “silenced,” emanating from thecbb 3 oxidase encoded by the ccoNOQPoperon under aerobic conditions. The dominant effect of theccoP mutation in the FnrL mutant strain with respect to spectral complex formation under aerobic conditions and restoration of a PS-positive phenotype suggested that inactivation of thecbb 3 oxidase to some extent bypasses the requirement for FnrL in the formation of spectral complexes. Additional analyses revealed that anaerobic induction of thebchE, hemN, and hemZ genes, which are involved in the tetrapyrrole biosynthetic pathways, requires FnrL. Thus, FnrL appears to be involved at multiple loci involved in the regulation of PS gene expression. Additionally, bchE was also shown to be regulated by the PrrBA two-component system, in conjunction with hemN and hemZ. These and other results to be discussed permit us to more accurately describe the role of FnrL as well as the interactions between the FnrL, PrrBA, and other regulatory circuits in the regulation of PS gene expression.

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Physiological role of pyruvate oxidase in the aerobic metabolism of Lactobacillus plantarum.

Journal of Bacteriology ◽

10.1128/jb.160.1.462-465.1984 ◽

1984 ◽

Vol 160 (1) ◽

pp. 462-465 ◽

Cited By ~ 48

Author(s):

B Sedewitz ◽

K H Schleifer ◽

F Götz

Keyword(s):

Lactobacillus Plantarum ◽

Physiological Role ◽

Aerobic Metabolism ◽

Pyruvate Oxidase

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Transcriptional Regulation of the Flavohemoglobin Gene for Aerobic Nitric Oxide Detoxification by the Second Nitric Oxide-Responsive Regulator of Pseudomonas aeruginosa

Journal of Bacteriology ◽

10.1128/jb.187.12.3960-3968.2005 ◽

2005 ◽

Vol 187 (12) ◽

pp. 3960-3968 ◽

Cited By ~ 61

Author(s):

Hiroyuki Arai ◽

Michiko Hayashi ◽

Azusa Kuroi ◽

Masaharu Ishii ◽

Yasuo Igarashi

Keyword(s):

Nitric Oxide ◽

Pseudomonas Aeruginosa ◽

Mutant Strain ◽

Regulatory Gene ◽

Physiological Role ◽

Nitrate Respiration ◽

Binding Motif ◽

Aerobic Conditions ◽

Mutant Strains ◽

Denitrification Genes

ABSTRACT The regulatory gene for a σ54-dependent-type transcriptional regulator, fhpR, is located upstream of the fhp gene for flavohemoglobin in Pseudomonas aeruginosa. Transcription of fhp was induced by nitrate, nitrite, nitric oxide (NO), and NO-generating reagents. Analysis of the fhp promoter activity in mutant strains deficient in the denitrification enzymes indicated that the promoter was regulated by NO or related reactive nitrogen species. The NO-responsive regulation was operative in a mutant strain deficient in DNR (dissimilatory nitrate respiration regulator), which is the NO-responsive regulator required for expression of the denitrification genes. A binding motif for σ54 was found in the promoter region of fhp, but an FNR (fumarate nitrate reductase regulator) box was not. The fhp promoter was inactive in the fhpR or rpoN mutant strain, suggesting that the NO-sensing regulation of the fhp promoter was mediated by FhpR. The DNR-dependent denitrification promoters (nirS, norC, and nosR) were active in the fhpR or rpoN mutants. These results indicated that P. aeruginosa has at least two independent NO-responsive regulatory systems. The fhp or fhpR mutant strains showed sensitivity to NO-generating reagents under aerobic conditions but not under anaerobic conditions. These mutants also showed significantly low aerobic NO consumption activity, indicating that the physiological role of flavohemoglobin in P. aeruginosa is detoxification of NO under aerobic conditions.

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