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 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 Natural variation inC. elegansarsenic toxicity is explained by differences in branched chain amino acid metabolism

2018 ◽  
Author(s):  
Stefan Zdraljevic ◽  
Bennett W. Fox ◽  
Christine Strand ◽  
Oishika Panda ◽  
Francisco J. Tenjo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Amino Acid ◽  
Human Populations ◽  
C Elegans ◽  
Branched Chain Amino Acid ◽  
Branched Chain Fatty Acids ◽  
Synonymous Variant ◽  
Branched Chain ◽  
Lipoyl Domain ◽  
Chain Fatty Acids

AbstractWe find that variation in thedbt-1gene underlies natural differences inCaenorhabditis elegansresponses to the toxin arsenic. This gene encodes the E2 subunit of the branched-chain α-keto acid dehydrogenase (BCKDH) complex, a core component of branched-chain amino acid (BCAA) metabolism. We causally linked a non-synonymous variant in the conserved lipoyl domain of DBT-1 to differential arsenic responses. Using targeted metabolomics and chemical supplementation, we demonstrate that differences in responses to arsenic are caused by variation in iso-branched chain fatty acids. Additionally, we show that levels of branched chain fatty acids in human cells are perturbed by arsenic treatment. This finding has broad implications for arsenic toxicity and for arsenic-focused chemotherapeutics across human populations. Our study implicates the BCKDH complex and BCAA metabolism in arsenic responses, demonstrating the power ofC. elegansnatural genetic diversity to identify novel mechanisms by which environmental toxins affect organismal physiology.

scholarly journals Fatty Acid Production from Amino Acids and α-Keto Acids by Brevibacterium linens BL2

2004 ◽  
Vol 70 (11) ◽  
pp. 6385-6393 ◽  
Author(s):  
Balasubramanian Ganesan ◽  
Kimberly Seefeldt ◽  
Bart C. Weimer
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Draft Genome ◽  
Brevibacterium Linens ◽  
Carbohydrate Starvation ◽  
Branched Chain Fatty Acids ◽  
Keto Acids ◽  
Branched Chain ◽  
Chain Fatty Acids

ABSTRACT Low concentrations of branched-chain fatty acids, such as isobutyric and isovaleric acids, develop during the ripening of hard cheeses and contribute to the beneficial flavor profile. Catabolism of amino acids, such as branched-chain amino acids, by bacteria via aminotransferase reactions and α-keto acids is one mechanism to generate these flavorful compounds; however, metabolism of α-keto acids to flavor-associated compounds is controversial. The objective of this study was to determine the ability of Brevibacterium linens BL2 to produce fatty acids from amino acids and α-keto acids and determine the occurrence of the likely genes in the draft genome sequence. BL2 catabolized amino acids to fatty acids only under carbohydrate starvation conditions. The primary fatty acid end products from leucine were isovaleric acid, acetic acid, and propionic acid. In contrast, logarithmic-phase cells of BL2 produced fatty acids from α-keto acids only. BL2 also converted α-keto acids to branched-chain fatty acids after carbohydrate starvation was achieved. At least 100 genes are potentially involved in five different metabolic pathways. The genome of B. linens ATCC 9174 contained these genes for production and degradation of fatty acids. These data indicate that brevibacteria have the ability to produce fatty acids from amino and α-keto acids and that carbon metabolism is important in regulating this event.

scholarly journals Natural variation in C. elegans arsenic toxicity is explained by differences in branched chain amino acid metabolism

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Stefan Zdraljevic ◽  
Bennett William Fox ◽  
Christine Strand ◽  
Oishika Panda ◽  
Francisco J Tenjo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Amino Acid ◽  
Editorial Note ◽  
Human Populations ◽  
Arsenic Toxicity ◽  
C Elegans ◽  
Branched Chain Amino Acid ◽  
Branched Chain Fatty Acids ◽  
Branched Chain ◽  
Chain Fatty Acids

We find that variation in the dbt-1 gene underlies natural differences in Caenorhabditis elegans responses to the toxin arsenic. This gene encodes the E2 subunit of the branched-chain α-keto acid dehydrogenase (BCKDH) complex, a core component of branched-chain amino acid (BCAA) metabolism. We causally linked a non-synonymous variant in the conserved lipoyl domain of DBT-1 to differential arsenic responses. Using targeted metabolomics and chemical supplementation, we demonstrate that differences in responses to arsenic are caused by variation in iso-branched chain fatty acids. Additionally, we show that levels of branched chain fatty acids in human cells are perturbed by arsenic treatment. This finding has broad implications for arsenic toxicity and for arsenic-focused chemotherapeutics across human populations. Our study implicates the BCKDH complex and BCAA metabolism in arsenic responses, demonstrating the power of C. elegans natural genetic diversity to identify novel mechanisms by which environmental toxins affect organismal physiology.Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (<xref ref-type="decision-letter" rid="SA1">see decision letter</xref>).

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