BIOSYNTHESIS OF BRANCHED-CHAIN FATTY ACIDS: IV. FACTORS AFFECTING RELATIVE ABUNDANCE OF FATTY ACIDS PRODUCED BY BACILLUS SUBTILIS

1966 ◽  
Vol 12 (3) ◽  
pp. 501-514 ◽  
Author(s):  
Toshi Kaneda

The fatty acids produced by Bacillus subtilis may be grouped into four pairs: 12-methyltetradecanoic and 14-methylhexadecanoic acids (anteiso-C15and anteiso-C17), 13-methyltetradecanoic and 15-methylhexadecanoic acids (iso-C15and iso-C17), 12-methyltridecanoic and 14-methylpentadecanoic acids (iso-C14and iso-C16), and myristic and palmitic acids (n-C14and n-C16). Any one of the branched-chain amino acids, L-isoleucine, L-leucine, or L-valine, or of the branched short-chain fatty acids, α-methylbutyrate, isovalerate, or isobutyrate, added to the glucose – yeast extract medium increased the synthesis of the specific pairs of fatty acids structurally related to the added substrate and decreased the synthesis of other fatty acids. This indicates that the relative abundance of branched-chain fatty acids in B. subtilis is a function of the relative availability of the precursors of the terminal portions of the fatty acids, presumably α-methylbutyryl-CoA, isovaleryl-CoA, and isobutyryl-CoA. This mechanism is consistent with the relative abundances of branched-chain fatty acids found in mutants of B. subtilis which require particular branched-chain amino acids. The biotin content of the culture medium and the length of incubation time also affected the relative abundance of the fatty acids.

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1151
Author(s):  
Sandra Meyer ◽  
Denise K. Gessner ◽  
Garima Maheshwari ◽  
Julia Röhrig ◽  
Theresa Friedhoff ◽  
...  

The hypothesis tested was that dietary inclusion of insect meal (IM) causes an alteration in the cecal microbiota composition and its fermentation activity of growing pigs. Five-week-old male crossbred pigs were randomly assigned to three groups of 10 pigs each, and fed isonitrogenous diets either without (CON) or with 5% IM (IM5) or 10% IM (IM10) from Tenebrio molitor larvae for four weeks. The relative abundance of the phylum Bacteroidetes was lower in group IM10 than in group CON (p < 0.05), whereas the relative abundance of Firmicutes and the Firmicutes:Bacteroidetes-ratio tended to be higher in groups IM10 and IM5 than in group CON (p < 0.1). The relative abundance of the Proteobacteria tended to be higher in group IM10 than in groups CON and IM5 (p < 0.1). The concentrations of the total short-chain fatty acids in the cecal digesta did not differ between the three groups, but the concentrations of the branched-chain fatty acids in the cecal digesta were higher in group IM5 and IM10 than in group CON (p < 0.05). The present study shows for the first time that the replacement of soybean meal by Tenebrio molitor larvae meal causes a shift of the cecal microbial community and its fermentation activity in growing pigs.


Metabolomics ◽  
2013 ◽  
Vol 9 (4) ◽  
pp. 818-827 ◽  
Author(s):  
Xiaojiao Zheng ◽  
Yunping Qiu ◽  
Wei Zhong ◽  
Sarah Baxter ◽  
Mingming Su ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Shi ◽  
Di Zhao ◽  
Fan Zhao ◽  
Chong Wang ◽  
Galia Zamaratskaia ◽  
...  

AbstractThis study was aimed to evaluate the differences in the composition of gut microbiota, tryptophan metabolites and short-chain fatty acids in feces between volunteers who frequently ate chicken and who frequently ate pork. Twenty male chicken-eaters and 20 male pork-eaters of 18 and 30 years old were recruited to collect feces samples for analyses of gut microbiota composition, short-chain fatty acids and tryptophan metabolites. Chicken-eaters had more diverse gut microbiota and higher abundance of Prevotella 9, Dialister, Faecalibacterium, Megamonas, and Prevotella 2. However, pork-eaters had higher relative abundance of Bacteroides, Faecalibacterium, Roseburia, Dialister, and Ruminococcus 2. In addition, chicken-eaters had high contents of skatole and indole in feces than pork-eaters, as well as higher contents of total short chain fatty acids, in particular for acetic acid, propionic acid, and branched chain fatty acids. The Spearman’s correlation analysis revealed that the abundance of Prevotella 2 and Prevotella 9 was positively correlated with levels of fecal skatole, indole and short-chain fatty acids. Thus, intake of chicken diet may increase the risk of skatole- and indole-induced diseases by altering gut microbiota.


2016 ◽  
Vol 7 (4) ◽  
pp. 1805-1813 ◽  
Author(s):  
Junyi Yang ◽  
Devin J. Rose

A diet high in whole grains, dry beans, and certain vegetables that contributed dietary fiber, plant protein, and B vitamins resulted in high short chain fatty acids, while a diet high in diary and processed meats that provided cholesterol and little fiber resulted in high branched chain fatty acids and ammonia during fecal fermentation of inulin.


1982 ◽  
Vol 152 (1) ◽  
pp. 246-254
Author(s):  
Caroline S. Harwood ◽  
Ercole Canale-Parola

Spirochete MA-2, which is anaerobic, ferments glucose, forming acetate as a major product. The spirochete also ferments (but does not utilize as growth substrates) small amounts of l -leucine, l -isoleucine, and l -valine, forming the branched-chain fatty acids isovalerate, 2-methylbutyrate, and isobutyrate, respectively, as end products. Energy generated through the fermentation of these amino acids is utilized to prolong cell survival under conditions of growth substrate starvation. A branched-chain fatty acid kinase and two acetate kinase isozymes were resolved from spirochete MA-2 cell extracts. Kinase activity was followed by measuring the formation of acyl phosphate from fatty acid and ATP. The branched-chain fatty acid kinase was active with isobutyrate, 2-methylbutyrate, isovalerate, butyrate, valerate, or propionate as a substrate but not with acetate as a substrate. The acetate kinase isozymes were active with acetate and propionate as substrates but not with longer-chain fatty acids as substrates. The acetate kinase isozymes and the branched-chain fatty acid kinase differed in nucleoside triphosphate and cation specificities. Each acetate kinase isozyme had an apparent molecular weight of approximately 125,000, whereas the branched-chain fatty acid kinase had a molecular weight of approximately 76,000. These results show that spirochete MA-2 synthesizes a branched-chain fatty acid kinase specific for leucine, isoleucine, and valine fermentation. It is likely that a phosphate branched-chain amino acids is also synthesized by spirochete MA-2. Thus, in spirochete MA-2, physiological mechanisms have evolved which serve specifically to generate maintenance energy from branched-chain amino acids.


1971 ◽  
Vol 17 (2) ◽  
pp. 269-275 ◽  
Author(s):  
Toshi Kaneda

Factors affecting relative proportions of long-chain fatty acids produced by the growing cells of Bacillus cereus have been studied. The organism produces nine branched (i-C12, i-C13, i-C14, i-C15, i-C16, i-C17, a-C13, a-C15, and a-C17), two normal (n-C14 and n-C16), and four monounsaturated (i-C161−, i-C17−1, a-C171−, and n-C161−), in addition to some minor fatty acids. On the basis of biosynthetic relationships these are grouped into four series: anteiso odd-numbered, iso odd-numbered, iso even-numbered, and normal even-numbered. The proportion of the normal series of fatty acids is generally not changed by varying growth conditions. The proportions of the three series of branched-chain fatty acids, however, are greatly affected depending upon growth phase and culture medium used. Younger cells tend to produce the four series in a closer ratio (1.5/1.8/0.8/1.0), whereas older cells produce four series in a wider ratio (1/2.2/0.8/1.0).The precursors of the terminal portions of branched-chain fatty acids, L-leucine, L-isoleucine, L-valine, and the related substrates, affected greatly the ratio of the three series of branched-chain fatty acids. Apparently the synthesis of iso odd-numbered acids is more tightly controlled than the synthesis of the two other series of fatty acids. Data suggest that this regulation is very likely to be due to the substrate specificity of the enzyme(s) involved in the fatty acid synthesis, rather than the relative availability of the precursors.


2009 ◽  
Vol 191 (7) ◽  
pp. 2187-2196 ◽  
Author(s):  
Kristie Keeney ◽  
Lisa Colosi ◽  
Walter Weber ◽  
Mary O'Riordan

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.


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