scholarly journals Role of Branched-Chain Fatty Acids in pH Stress Tolerance in Listeria monocytogenes

2006 ◽  
Vol 73 (3) ◽  
pp. 997-1001 ◽  
Author(s):  
Efstathios S. Giotis ◽  
David A. McDowell ◽  
Ian S. Blair ◽  
Brian J. Wilkinson
Keyword(s):  
Fatty Acids ◽  
Listeria Monocytogenes ◽  
Stress Tolerance ◽  
Ph Sensitive ◽  
Branched Chain Fatty Acids ◽  
Alkaline Conditions ◽  
Branched Chain ◽  
Ph Adaptation ◽  
Chain Fatty Acids

ABSTRACT In alkaline conditions, Listeria monocytogenes cells develop higher proportions of branched-chain fatty acids (FAs), including more anteiso forms. In acid conditions, the opposite occurs. Reduced growth of pH-sensitive mutants at adverse pH (5.0/9.0) was alleviated by the addition of 2-methylbutyrate (an anteiso-FA precursor), suggesting that anteiso-FAs are important in adaptation to adverse pH. The balance between anteiso- and iso-FAs may be more important than changes in the amounts and/or degrees of saturation of FAs in pH adaptation.

scholarly journals Generation of Branched-Chain Fatty Acids through Lipoate-Dependent Metabolism Facilitates Intracellular Growth of Listeria monocytogenes

2009 ◽  
Vol 191 (7) ◽  
pp. 2187-2196 ◽  
Author(s):  
Kristie Keeney ◽  
Lisa Colosi ◽  
Walter Weber ◽  
Mary O'Riordan
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Listeria Monocytogenes ◽  
Host Cells ◽  
Metabolic Enzyme ◽  
Intracellular Growth ◽  
Branched Chain Fatty Acids ◽  
Branched Chain ◽  
Chain Fatty Acids

ABSTRACT The gram-positive bacterial pathogen Listeria monocytogenes has evolved mechanisms to rapidly replicate in the host cytosol, implying efficient utilization of host-derived nutrients. However, the contribution of host nutrient scavenging versus that of bacterial biosynthesis toward rapid intracellular growth remains unclear. Nutrients that contribute to growth of L. monocytogenes include branched-chain fatty acids (BCFAs), amino acids, and other metabolic intermediates generated from acyl-coenzyme A, which is synthesized using lipoylated metabolic enzyme complexes. To characterize which biosynthetic pathways support replication of L. monocytogenes inside the host cytosol, we impaired lipoate-dependent metabolism by disrupting two lipoate ligase genes that are responsible for bacterial protein lipoylation. Interrupting lipoate-dependent metabolism modestly impaired replication in rich broth medium but strongly inhibited growth in defined medium and host cells and impaired the generation of BCFAs. Addition of short BCFAs and amino acids restored growth of the A1A2-deficient (A1A2−) mutant in minimal medium, implying that lipoate-dependent metabolism generates amino acids and BCFAs. BCFAs alone rescued intracellular growth and spread in L2 fibroblasts of the A1A2− mutant. Lipoate-dependent metabolism was also required in vivo, as a wild-type strain robustly outcompeted the lipoylation-deficient mutant in a murine model of listeriosis. The results of this study suggest that lipoate-dependent metabolism contributes to both amino acid and BCFA biosynthesis and that BCFA biosynthesis is preferentially required for intracellular growth of L. monocytogenes.

scholarly journals Variation of Branched-Chain Fatty Acids Marks the Normal Physiological Range for Growth in Listeria monocytogenes

2002 ◽  
Vol 68 (6) ◽  
pp. 2809-2813 ◽  
Author(s):  
David S. Nichols ◽  
Kirsty A. Presser ◽  
June Olley ◽  
Tom Ross ◽  
Tom A. McMeekin
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Acid Composition ◽  
Physiological Range ◽  
Branched Chain Fatty Acids ◽  
Branched Chain ◽  
High Degree ◽  
Chain Fatty Acids

ABSTRACT The fatty acid composition of Listeria monocytogenes Scott A was determined by close-interval sampling over the entire biokinetic temperature range. There was a high degree of variation in the percentage of branched-chain fatty acids at any given temperature. The percentage of branched C17 components increased with growth temperature in a linear manner. However, the percentages of iso-C15:0 (i15:0) and anteiso-C15:0 (a15:0) were well described by third-order and second-order polynomial curves, respectively. There were specific temperature regions where the proportion of branched-chain fatty acids deviated significantly from the trend established over the entire growth range. In the region from 12 to 13°C there were significant deviations in the percentages of both i15:0 and a15:0 together with a suggested deviation in a17:0, resulting in a significant change in the total branched-chain fatty acids. In the 31 to 33°C region the percentage of total branched-chain components exhibited a significant deviation. The observed perturbations in fatty acid composition occurred near the estimated boundaries of the normal physiological range for growth.

scholarly journals Branched-Chain Fatty Acids Promote Listeria monocytogenes Intracellular Infection and Virulence

2010 ◽  
Vol 78 (11) ◽  
pp. 4667-4673 ◽  
Author(s):  
Yvonne Sun ◽  
Mary X. D. O'Riordan
Keyword(s):  
Fatty Acids ◽  
Listeria Monocytogenes ◽  
Antimicrobial Agents ◽  
Listeriolysin O ◽  
Dominant Group ◽  
Growth And Survival ◽  
Branched Chain Fatty Acids ◽  
Culture Models ◽  
Branched Chain ◽  
Chain Fatty Acids

ABSTRACT Anteiso-branched-chain fatty acids (BCFA) represent the dominant group of membrane fatty acids and have been established as crucial determinants in resistance against environmental stresses in Listeria monocytogenes, a facultative intracellular pathogen. Here, we investigate the role of anteiso-BCFA in L. monocytogenes virulence by using mutants deficient in branched-chain alpha-keto acid dehydrogenase (BKD), an enzyme complex involved in the synthesis of BCFA. In tissue culture models of infection, anteiso-BCFA contributed to intracellular growth and survival in macrophages and significantly enhanced plaque formation upon prolonged infection in L2 fibroblasts. The intracellular defects observed could be attributed partially to insufficient listeriolysin O (LLO) production, indicating a requirement for anteiso-BCFA in regulating virulence factor production. In a murine model of infection, the BKD-deficient mutant was highly attenuated, further emphasizing the importance of BKD-mediated metabolism in L. monocytogenes virulence. This study demonstrates an underappreciated role for BCFA in bacterial pathogenesis, which may provide insight into the development and application of antimicrobial agents.

scholarly journals Role of Aminotransferase IlvE in Production of Branched-Chain Fatty Acids by Lactococcus lactis subsp. lactis

2004 ◽  
Vol 70 (1) ◽  
pp. 638-641 ◽  
Author(s):  
Balasubramanian Ganesan ◽  
Bart C. Weimer
Keyword(s):  
Fatty Acids ◽  
Lactococcus Lactis ◽  
Deletion Mutant ◽  
Keto Acid ◽  
Branched Chain Amino Acid ◽  
Branched Chain Fatty Acids ◽  
Keto Acids ◽  
Branched Chain ◽  
Chain Fatty Acids

ABSTRACT The objective of this study was to determine the role of a lactococcal branched-chain amino acid aminotransferase gene, ilvE, in the production of branched-chain fatty acids. Lactococcus lactis subsp. lactis LM0230 and an ilvE deletion mutant, JLS450, produced branched-chain fatty acids from amino and α-keto acids at levels above α-keto acid spontaneous degradation and the fatty acids' flavor thresholds. The deletion mutant produced the same amounts of branched-chain fatty acids from precursor amino acids as did the parent. This was not the case, however, for the production of branched-chain fatty acids from the corresponding precursor α-keto acids. The deletion mutant produced a set of fatty acids different from that produced by the parent. We concluded from these observations that ilvE plays a role in the specific type of fatty acids produced but has little influence on the total amount of fatty acids produced by lactococci.

scholarly journals Short- and Branched-Chain Fatty Acids as Fecal Markers for Microbiota Activity in Vegans and Omnivores

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1808
Author(s):  
Iris Trefflich ◽  
Stefan Dietrich ◽  
Annett Braune ◽  
Klaus Abraham ◽  
Cornelia Weikert
Keyword(s):  
Fatty Acids ◽  
Ammonia Concentration ◽  
Cross Sectional Study ◽  
Vegan Diet ◽  
Microbiota Composition ◽  
Cross Sectional ◽  
Branched Chain Fatty Acids ◽  
Branched Chain ◽  
Fecal Ph ◽  
Chain Fatty Acids

A vegan diet could impact microbiota composition and bacterial metabolites like short-chain (SCFA) and branched-chain fatty acids (BCFA). The aim of this study was to compare the concentrations of SCFA, BCFA, ammonia, and fecal pH between vegans and omnivores. In this cross-sectional study (vegans n = 36; omnivores n = 36), microbiota composition, fecal SCFA, BCFA, and ammonia concentrations and pH were analyzed in complete stool samples. A random forest regression (RFR) was used to identify bacteria predicting SCFA/BCFA concentrations in vegans and omnivores. No significant differences in SCFA and BCFA concentrations were observed between vegans and omnivores. Fecal pH (p = 0.005) and ammonia concentration (p = 0.01) were significantly lower in vegans than in omnivores, while fiber intake was higher (p < 0.0001). Shannon diversity was higher in omnivores compared to vegans on species level (p = 0.04) only. In vegans, a cluster of Faecalibacterium prausnitzii, Prevotella copri, Dialister spp., and Eubacterium spp. was predictive for SCFA and BCFA concentrations. In omnivores, Bacteroides spp., Clostridium spp., Ruminococcus spp., and Prevotella copri were predictive. Though SCFA and BCFA did not differ between vegans and omnivores, the results of the RFR suggest that bacterial functionality may be adapted to varying nutrient availability in these diets.

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