scholarly journals Insights into the Mechanism of Homeoviscous Adaptation to Low Temperature in Branched-Chain Fatty Acid-Containing Bacteria through Modeling FabH Kinetics from the Foodborne Pathogen Listeria monocytogenes

2016 ◽  
Vol 7 ◽  
Author(s):  
Lauren P. Saunders ◽  
Suranjana Sen ◽  
Brian J. Wilkinson ◽  
Craig Gatto
Keyword(s):  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Low Temperature ◽  
Foodborne Pathogen ◽  
Chain Fatty Acid ◽  
Homeoviscous Adaptation ◽  
Branched Chain

scholarly journals Exogenous Isoleucine and Fatty Acid Shortening Ensure the High Content of Anteiso-C15:0 Fatty Acid Required for Low-Temperature Growth of Listeria monocytogenes

2005 ◽  
Vol 71 (12) ◽  
pp. 8002-8007 ◽  
Author(s):  
Kun Zhu ◽  
Xiang Ding ◽  
Mudcharee Julotok ◽  
Brian J. Wilkinson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Low Temperature ◽  
Fatty Acid Profile ◽  
Acyl Carrier Protein ◽  
Critical Role ◽  
Chain Fatty Acid ◽  
Fatty Acid Chain ◽  
Branched Chain

ABSTRACT Previous studies have demonstrated that the branched-chain fatty acid anteiso-C15:0 plays a critical role in the growth of Listeria monocytogenes at low temperatures by ensuring sufficient membrane fluidity. Studies utilizing a chemically defined minimal medium revealed that the anteiso fatty acid precursor isoleucine largely determined the fatty acid profile and fatty acid response of the organism to lowered growth temperature. When isoleucine was sufficient, the fatty acid profile was very uniform, with anteiso fatty acids comprising up to 95% of total fatty acid, and the major fatty acid adjustment to low temperature was fatty acid chain shortening, which resulted in an increase of anteiso-C15:0 solely at the expense of anteiso-C17:0. When isoleucine was not supplied, the fatty acid profile became more complex and was readily modified by leucine, which resulted in a significant increase of corresponding iso fatty acids and an inability to grow at 10°C. Under this condition, the increase of anteiso-C15:0 at low temperature resulted from the combined effect of increasing the anteiso:iso ratio and chain shortening. A branched-chain α-keto acid dehydrogenase-defective strain largely lost the ability to increase the anteiso:iso ratio. Cerulenin, an inhibitor of β-ketoacyl-acyl carrier protein synthase (FabF), induced a similar fatty acid chain shortening as low temperature did. We propose that the anteiso precursor preferences of enzymes in the branched-chain fatty acid biosynthesis pathway ensure a high production of anteiso fatty acids, and cold-regulated chain shortening results in a further increase of anteiso-C15:0 at the expense of anteiso-C17:0.

scholarly journals Influence of Fatty Acid Precursors, Including Food Preservatives, on the Growth and Fatty Acid Composition of Listeria monocytogenes at 37 and 10�C

2010 ◽  
Vol 76 (5) ◽  
pp. 1423-1432 ◽  
Author(s):  
Mudcharee Julotok ◽  
Atul K. Singh ◽  
Craig Gatto ◽  
Brian J. Wilkinson
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Carboxylic Acid ◽  
Acid Composition ◽  
Acyl Carrier Protein ◽  
Straight Chain ◽  
Food Preservatives ◽  
Homeoviscous Adaptation ◽  
Branched Chain

ABSTRACT Listeria monocytogenes is a food-borne pathogen that grows at refrigeration temperatures and increases its content of anteiso-C15:0 fatty acid, which is believed to be a homeoviscous adaptation to ensure membrane fluidity, at these temperatures. As a possible novel approach for control of the growth of the organism, the influences of various fatty acid precursors, including branched-chain amino acids and branched- and straight-chain carboxylic acids, some of which are also well-established food preservatives, on the growth and fatty acid composition of the organism at 37�C and 10�C were studied in order to investigate whether the organism could be made to synthesize fatty acids that would result in impaired growth at low temperatures. The results indicate that the fatty acid composition of L. monocytogenes could be modulated by the feeding of branched-chain amino acid, C4, C5, and C6 branched-chain carboxylic acid, and C3 and C4 straight-chain carboxylic acid fatty acid precursors, but the growth-inhibitory effects of several preservatives were independent of effects on fatty acid composition, which were minor in the case of preservatives metabolized via acetyl coenzyme A. The ability of a precursor to modify fatty acid composition was probably a reflection of the substrate specificities of the first enzyme, FabH, in the condensation of primers of fatty acid biosynthesis with malonyl acyl carrier protein.

scholarly journals FabH selectivity for anteiso branched-chain fatty acid precursors in low-temperature adaptation inListeria monocytogenes

2009 ◽  
Vol 301 (2) ◽  
pp. 188-192 ◽  
Author(s):  
Atul K. Singh ◽  
Yong-Mei Zhang ◽  
Kun Zhu ◽  
Chitra Subramanian ◽  
Zhong Li ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Low Temperature ◽  
Chain Fatty Acid ◽  
Temperature Adaptation ◽  
Branched Chain ◽  
Low Temperature Adaptation

Precursor and temperature modulation of fatty acid composition and growth of Listeria monocytogenes cold-sensitive mutants with transposon-interrupted branched-chain α-keto acid dehydrogenase

Microbiology ◽  
2005 ◽  
Vol 151 (2) ◽  
pp. 615-623 ◽  
Author(s):  
Kun Zhu ◽  
Darrell O. Bayles ◽  
Anming Xiong ◽  
R. K. Jayaswal ◽  
Brian J. Wilkinson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Low Temperature ◽  
Cold Sensitivity ◽  
Temperature Modulation ◽  
Keto Acid ◽  
Acid Dehydrogenase ◽  
Cold Sensitive ◽  
Branched Chain

Branched-chain fatty acids (BCFAs) typically constitute more than 90 % of the fatty acids of Listeria monocytogenes. The authors have previously described two Tn917-induced, cold-sensitive, BCFA-deficient (<40 %) L. monocytogenes mutants (cld-1 and cld-2) with lowered membrane fluidity. Sequence analyses revealed that Tn917 was inserted into different genes of the branched-chain α-keto acid dehydrogenase cluster (bkd) in these two mutants. The cold-sensitivity and BCFA deficiency of cld-1, in which Tn917 was inserted into bkdB, were complemented in trans by cloned bkdB. The growth and corresponding BCFA content of the mutants at 37 °C were stimulated by fatty acid precursors bypassing Bkd, 2-methylbutyrate (precursor for odd-numbered anteiso-fatty acids), isobutyrate (precursor for even-numbered iso-fatty acids) and isovalerate (precursor for odd-numbered iso-fatty acids). In contrast, the corresponding Bkd substrates, α-ketomethylvalerate, α-ketoisovalerate and α-ketoisocaproate, exhibited much poorer activity. At 26 °C, 2-methylbutyrate and isovalerate stimulated the growth of the mutants, and at 10 °C, only 2-methylbutyrate stimulated growth. Pyruvate depressed the BCFA content of cld-2 from 33 % to 27 %, which may be close to the minimum BCFA requirement for L. monocytogenes. The transcription of bkd was enhanced by Bkd substrates, but not by low temperature. When provided with the BCFA precursors, cld-2 was able to increase its anteiso-C15 : 0 fatty acid content at 10 °C compared to 37 °C, which is the characteristic response of L. monocytogenes to low temperature. This implies that Bkd is not the major cold-regulation point of BCFA synthesis.

scholarly journals Mitochondrial and peroxisomal beta oxidation of the branched chain fatty acid 2-methylpalmitate in rat liver.

1991 ◽  
Vol 266 (36) ◽  
pp. 24670-24675 ◽  
Author(s):  
G. Vanhove ◽  
P.P. Van Veldhoven ◽  
F. Vanhoutte ◽  
G. Parmentier ◽  
H.J. Eyssen ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Rat Liver ◽  
Chain Fatty Acid ◽  
Beta Oxidation ◽  
Branched Chain
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