scholarly journals Cultivation of Spore-Forming Gut Microbes Using a Combination of Bile Acids and Amino Acids

2021 ◽  
Vol 9 (8) ◽  
pp. 1651
Author(s):  
Sakura Onizuka ◽  
Masaru Tanaka ◽  
Riko Mishima ◽  
Jiro Nakayama
Keyword(s):  
Amino Acids ◽  
New Species ◽  
Bile Acid ◽  
Bile Acids ◽  
Agar Medium ◽  
Intestinal Bacteria ◽  
The Other ◽  
Gut Microbes ◽  
Operational Taxonomic Units

Spores of certain species belonging to Firmicutes are efficiently germinated by nutrient germinators, such as amino acids, in addition to bile acid. We attempted to culture difficult-to-culture or yet-to-be cultured spore-forming intestinal bacteria, using a combination of bile acids and amino acids. The combination increased the number of colonies that formed on agar medium plated with ethanol-treated feces. The operational taxonomic units of these colonized bacteria were classified into two types. One type was colonized only by the bile acid (BA) mixture and the other type was colonized using amino acids, in addition to the BA mixture. The latter contained 13 species, in addition to 14 species of the former type, which mostly corresponds to anaerobic difficult-to-culture Clostridiales species, including several new species candidates. The use of a combination of BAs and amino acids effectively increased the culturability of spore-forming intestinal bacteria.

Electrostatic and potential cation-π forces may guide the interaction of extracellular loop III with Na+ and bile acids for human apical Na+-dependent bile acid transporter

2008 ◽  
Vol 410 (2) ◽  
pp. 391-400 ◽  
Author(s):  
Antara Banerjee ◽  
Naissan Hussainzada ◽  
Akash Khandelwal ◽  
Peter W. Swaan
Keyword(s):  
Amino Acids ◽  
Bile Acid ◽  
Bile Acids ◽  
Conformational Changes ◽  
Electrostatic Interactions ◽  
Extracellular Loop ◽  
Membrane Expression ◽  
Ligand Interaction ◽  
Bile Acid Transporter ◽  
Acid Transporter

The hASBT (human apical Na+-dependent bile acid transporter) constitutes a key target of anti-hypercholesterolaemic therapies and pro-drug approaches; physiologically, hASBT actively reclaims bile acids along the terminal ileum via Na+ co-transport. Previously, TM (transmembrane segment) 7 was identified as part of the putative substrate permeation pathway using SCAM (substitute cysteine accessibility mutagenesis). In the present study, SCAM was extended through EL3 (extracellular loop 3; residues Arg254–Val286) that leads into TM7 from the exofacial matrix. Activity of most EL3 mutants was significantly hampered upon cysteine substitution, whereas ten (out of 31) were functionally inactive (<10% activity). Since only E282C lacked plasma membrane expression, EL3 amino acids predominantly fulfill critical functional roles during transport. Oppositely charged membrane-impermeant MTS (methanethiosulfonate) reagents {MTSET [(2-trimethylammonium) ethyl MTS] and MTSES [(2-sulfonatoethyl) MTS]} produced mostly similar inhibition profiles wherein only middle and descending loop segments (residues Thr267–Val286) displayed significant MTS sensitivity. The presence of bile acid substrate significantly reduced the rates of MTS modification for all MTS-sensitive mutants, suggesting a functional association between EL3 residues and bile acids. Activity assessments at equilibrative [Na+] revealed numerous Na+-sensitive residues, possibly performing auxiliary functions during transport such as transduction of protein conformational changes during translocation. Integration of these data suggests ligand interaction points along EL3 via electrostatic interactions with Arg256, Glu261 and probably Glu282 and a potential cation-π interaction with Phe278. We conclude that EL3 amino acids are essential for hASBT activity, probably as primary substrate interaction points using long-range electrostatic attractive forces.

Sibling recognition and olfactory sensitivity in juvenile coho salmon (Oncorhynchus kisutch)

1986 ◽  
Vol 64 (4) ◽  
pp. 921-925 ◽  
Author(s):  
Thomas P. Quinn ◽  
Toshiaki J. Hara
Keyword(s):  
Amino Acids ◽  
Bile Acid ◽  
Bile Acids ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Olfactory Sensitivity ◽  
Secondary Role ◽  
Olfactory Sense ◽  
Sibling Recognition

Previous experiments indicated that juvenile coho salmon (Oncorhynchus kisutch) can distinguish the chemical traces of siblings from nonsiblings of their own population. The present study confirmed the finding that coho salmon use chemoreceptor systems to distinguish tankmate siblings from nonsiblings that they have not been reared with. However, salmon did not distinguish siblings from nonsiblings or maternal half-siblings if they had been reared together. Electrophysiological experiments demonstrated that the olfactory sense of young coho salmon can detect certain amino acids and a bile acid at concentrations of about 10−8 to 10−9 M. Additional tests suggest that bile acids are probably of primary importance in chemically characterizing conspecifics and amino acids play a secondary role.

scholarly journals Infection with novel Bacteroides phage BV01 alters host transcriptome and bile acid metabolism in a common human gut microbe

2020 ◽  
Author(s):  
Danielle E. Campbell ◽  
Lindsey K. Ly ◽  
Jason M. Ridlon ◽  
Ansel Hsiao ◽  
Rachel J. Whitaker ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Community Dynamics ◽  
Bile Acid Metabolism ◽  
Dependent Manner ◽  
Human Gut ◽  
Healthy Human ◽  
Transcriptomic Response ◽  
Gut Microbes ◽  
Host Interactions

ABSTRACTThe bacterial genus Bacteroides is among the most abundant and common taxa in the human gut, yet little is known about the phages infecting the group. Bacteroides phage BV01 (BV01) was identified as a prophage integrated on the chromosome of its host, Bacteroides vulgatus ATCC 8482. Phage BV01 is actively produced, and infects susceptible B. vulgatus hosts in the mouse gut. Infection with BV01 causes a generalized repression of the B. vulgatus transcriptome, downregulating 103 transcripts and upregulating only 12. Integration of BV01 disrupts the promoter sequence of a downstream gene encoding a putative tryptophan-rich sensory protein (tspO). Deletion of tspO and subsequent RNAseq analysis revealed that more than half of the differentially-regulated transcripts are shared with the BV01 lysogen, suggesting the transcriptomic response to BV01 is linked to tspO. Among these differentially-regulated transcripts are two encoding bile salt hydrolases. Bile acid deconjugation assays show that BV01 represses its host’s ability to hydrolyze bile acids in a tspO-dependent manner. Analysis of 256 published healthy human gut metagenomes suggests that phage integration adjacent to B. vulgatus-like tspO genes is rare within an individual, but common among humans. Finally, this work proposes a novel phage family that includes BV01, the Salyersviridae, whose host range spans the Bacteroides and is detectable in human-associated samples. Together, these findings highlight the importance of phage-host interactions to our understanding of how gut microbes sense and interact with their environment.IMPORTANCEThe links between human disease and the gut microbiome are numerous. Most mechanisms by which most gut microbes and their activities change and impact human health remain elusive. Phages, viruses that infect bacteria, are hypothesized to play a central role in modulating both community dynamics and functional activities. Here we have characterized an active prophage, BV01, which infects a pervasive and abundant human gut-associated species. BV01 infection alters its host’s transcriptional profile including its metabolism of bile acids, molecules implicated in mediating health and disease states in the gut. This highlights that prophages and other components of the variable genome should not be overlooked in bacterial genomes because they may dramatically alter host phenotypes. Furthermore, BV01 represents a new family of phages infecting human gut symbionts, providing a foundation for future investigations of phage-host interactions in these clinically-relevant but underexplored hosts.

EFFECTS OF ADRENALECTOMY AND CORTICOID REPLACEMENT ON BILE ACID CONJUGATION IN BILE FISTULA RATS

1963 ◽  
Vol 43 (2) ◽  
pp. 305-310 ◽  
Author(s):  
Kjell Hellström ◽  
Ove Strand
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Cholic Acid ◽  
The Other ◽  
Bile Fistula ◽  
Adrenalectomized Rats ◽  
Conjugated Bile Acids ◽  
Fistula Bile

ABSTRACT Bile fistula bile from male normal, sham-operated, adrenalectomized and cortisone substituted adrenalectomized rats was analyzed for free and conjugated bile acids. 40–50 per cent of the bile acids from adrenalectomized rats were conjugated with glycine as compared to less than 10 per cent in the other groups. The cortisone substituted adrenalectomized rats showed a lower glycine conjugation than normal rats. In the bile from adrenal-ectomized rats, free cholic acid corresponding to 2–5% of the conjugated bile acids was detected. In the bile from the other groups less than 1% of free cholic acid was found. The mechanism responsible for the abnormal conjugation pattern found in adrenalectomized rats is discussed.

scholarly journals Intestinal Absorption of Bile Salts

1990 ◽  
Vol 4 (2) ◽  
pp. 79-84 ◽  
Author(s):  
Karen Madsen
Keyword(s):  
Bile Acid ◽  
Bile Salt ◽  
Bile Acids ◽  
Intestinal Bacteria ◽  
Dietary Lipids ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Carrier Mechanism ◽  
Major Route ◽  
The Individual

Bile acids are secreted from the liver into the duodenum where they aid in the digestion and absorption of dietary lipids. Absorption of bile acids occurs through both ionic and nonionic diffusion in the jejunum and colon and through an active sodium ion-dependent carrier mechanism in the ileum. The prima, y bile acids synthesized in the liver can be converted by intestinal bacteria into secondary and tertiary bile acids. Bile acids may also be conjugated with glycine or taurine which results in an increase in the hydrophilicity and solubility of these compounds at physiological pH. The amount of passive diffusion of bile acids that occurs across the brush border membrane along the length of the entire intestine depends upon the ratio of ionized to nonionized bile acids coupled with the bile salt concentration and the individual permeability coefficients of monomers. Active transport of both conjugated and nonconjugated species of bile acids depends upon the presence of a single negative charge on the side chain. Maximal transport rates for bile acids are related to the number of hydroxyl groups present while the Michaelis-Menten constant for transport is dependent upon whether or not the bile acid is conjugated. Although active uptake of bile acids from the ileum has been considered the major route for bile salt absorption in the small intestine, the mechanism may actually be responsible for only a small proportion of the total bile acid pool absorbed from the lumen.

scholarly journals Evolutionary Analysis of Bile Acid-Conjugating Enzymes Reveals a Complex Duplication and Reciprocal Loss History

2019 ◽  
Vol 11 (11) ◽  
pp. 3256-3268
Author(s):  
Bogdan M Kirilenko ◽  
Lee R Hagey ◽  
Stephen Barnes ◽  
Charles N Falany ◽  
Michael Hiller
Keyword(s):  
Amino Acids ◽  
Bile Acid ◽  
Bile Acids ◽  
Active Site ◽  
Tandem Duplication ◽  
Catalytic Triad ◽  
Evolutionary Analysis ◽  
Genetic Origin ◽  
Enzymatic Function ◽  
Human Enzyme

Abstract To fulfill their physiological functions, bile acids are conjugated with amino acids. In humans, conjugation is catalyzed by bile acid coenzyme A: amino acid N-acyltransferase (BAAT), an enzyme with a highly conserved catalytic triad in its active site. Interestingly, the conjugated amino acids are highly variable among mammals, with some species conjugating bile acids with both glycine and taurine, whereas others conjugate only taurine. The genetic origin of these bile acid conjugation differences is unknown. Here, we tested whether mutations in BAAT’s catalytic triad could explain bile acid conjugation differences. Our comparative analysis of 118 mammals first revealed that the ancestor of placental mammals and marsupials possessed two genes, BAAT and BAATP1, that arose by a tandem duplication. This duplication was followed by numerous gene losses, including BAATP1 in humans. Losses of either BAAT or BAATP1 largely happened in a reciprocal fashion, suggesting that a single conjugating enzyme is generally sufficient for mammals. In intact BAAT and BAATP1 genes, we observed multiple changes in the catalytic triad between Cys and Ser residues. Surprisingly, although mutagenesis experiments with the human enzyme have shown that replacing Cys for Ser greatly diminishes the glycine-conjugating ability, across mammals we found that this residue provides little power in predicting the experimentally measured amino acids that are conjugated with bile acids. This suggests that the mechanism of BAAT’s enzymatic function is incompletely understood, despite relying on a classic catalytic triad. More generally, our evolutionary analysis indicates that results of mutagenesis experiments may not easily be extrapolatable to other species.

scholarly journals Bile acid conjugation and hepatic taurine concentration in rats fed on pectin

1989 ◽  
Vol 62 (3) ◽  
pp. 539-550 ◽  
Author(s):  
T. Ide ◽  
M. Horii ◽  
K. Kawashima ◽  
T. Yamamoto
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Biliary Excretion ◽  
The Other ◽  
Acid Excretion ◽  
Citrus Pectin ◽  
Taurine Concentration ◽  
Dietary Level ◽  
Biliary Bile Acid ◽  
Conjugated Bile Acids

A relationship between bile acid conjugation and hepatic taurine concentration was investigated in rats fed on citrus pectin. When rats were fed on the diets containing varying amounts of pectin (10, 30, 60 and 100 g/kg dietary levels), biliary excretion of bile acids increased as the dietary levels of pectin increased. The increase was entirely due to the glycine-conjugated bile acids. The biliary excretion of taurine-conjugated bile acid was somewhat decreased as the dietary level of the fibre increased. Consequently, most of the bile acids were conjugated with glycine in rats fed on the diet containing 100 g pectin/kg. On the other hand, dietary cellulose (60 and 100 g/kg) did not affect the biliary bile acid excretions. The major proportion of bile acids in rats receiving a fibre-free diet and the diets containing cellulose were conjugated with taurine. Hepatic taurine concentrations decreased as the dietary levels of pectin, but not of cellulose, increased. Although dietary pectin (100 g/kg) also slightly decreased the taurine concentration in the kidney, those concentrations in other non-hepatic tissues examined (heart, brain and serum) were unaffected by the dietary fibre. Supplementation of the diet containing 100 g pectin/kg with methionine (10 g/kg) and taurine (10 and 50 g/kg) strikingly increased hepatic taurine concentrations. In this situation, the conjugation of bile acid with glycine was almost abolished and taurine conjugates became abundant in the bile of these animals. It is suggested that dietary pectin mediated an increase in the biliary bile acid excretion which may have depleted the hepatic pool of taurine available for bile acid conjugation and, thus, increased glycine conjugation of bile acids.

scholarly journals Predominant conjugation with glycine of biliary and lumen bile acids in rats fed on pectin

1989 ◽  
Vol 61 (3) ◽  
pp. 545-557 ◽  
Author(s):  
T. Ide ◽  
M. Horii
Keyword(s):  
Small Intestine ◽  
Bile Acid ◽  
Bile Acids ◽  
Acid Content ◽  
Dietary Cholesterol ◽  
The Other ◽  
Cholesterol Feeding ◽  
Citrus Pectin ◽  
Bile Acid Concentration ◽  
Considerable Portion

1. Bile acids were analysed in the bile and lumen samples of rats which received a cholesterol-free or cholesterol-enriched (5 g/kg) diet free from fibre, or containing cellulose or citrus pectin at the level of 100 g/kg.2. Dietary pectin but not cellulose increased biliary bile acid concentration and excretion. Dietary cholesterol did not affect biliary bile acids quantitatively.3. Biliary bile acids were almost exclusively conjugated with glycine or taurine in the various experimental situations. The predominant portion of bile acids in rats fed on the cholesterol-free diet was conjugated with taurine when the diet was either free from fibre or contained cellulose; the ratio of bile acids conjugated with glycine: those conjugated with taurine (G:T) was less than 0·2. In contrast, with pectin as a fibre source, the conjugation with glycine increased enormously (G:T increased to approximately 4). Cholesterol enrichment of the diet also increased the glycine conjugation in all groups of rats. Even in this situation, the G:T was highest in rats fed on pectin.4. Pectin, but not cellulose, increased the bile acid content of the small intestine and caecum, both in rats fed on the cholesterol-free and cholesterol-enriched diets. Cholesterol feeding doubled the bile acid content of the caecum in rats fed on a fibre-free diet or a cellulose diet, but not in those fed on pectin. No such effect of cholesterol was observed in the small intestine, except for the ileal bile acid content in rats fed on cellulose.5. A considerable portion of the bile acids in the small intestine was deconjugated. The extent of the deconjugation was higher in the ileum than in the jejunum. As in the bile, G:T in rats fed on pectin (3·5·5) were higher than those in the other groups (0·05–1·05) in various situations. Also, cholesterol feeding considerably increased the ratio in all groups of rats.6. The observed dietary alteration of the partition of bile acids between glycine and taurine may be of physiological significance in regulating bile acid and lipid metabolism in rats.

scholarly journals Bile acid inhibition of basic and neutral glutathione S-transferases in rat liver

1983 ◽  
Vol 215 (3) ◽  
pp. 581-588 ◽  
Author(s):  
J D Hayes ◽  
J Chalmers
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Rat Liver ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
The Other ◽  
Purification Scheme ◽  
Glutathione S Transferases

A purification scheme is described for the neutral glutathione S-transferases of rat liver. Discontinuous sodium dodecyl sulphate/polyacrylamide-gel electrophoresis revealed that one of these enzymes contains a previously unidentified subunit, which has a molecular mass of 23 000 Da and has been designated Yn. Bile acids inhibited the activity of all the basic and neutral transferases investigated, but marked differences in the effects of bile acids on individual enzymes were observed. The activity of each transferase was inhibited more by lithocholate 3-sulphate than by chenodeoxycholate, which in turn was more inhibitory than cholate. The enzymes that were most sensitive to cholate inhibition were not found to be as readily inhibited as other transferases by chenodeoxycholate or lithocholate 3-sulphate. Conversely, the activity of transferase AA was more resistant to cholate, chenodeoxycholate and lithocholate 3-sulphate inhibition than was any of the other enzymes studied.

Problems of species and the features of geographical distribution in colonial volvocine algae (Chlorophyta)

2020 ◽  
Vol 54 (2) ◽  
pp. 299-311
Author(s):  
A. G. Desnitskiy
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
World Literature ◽  
The Other ◽  
Disjunct Distribution ◽  
Published Data ◽  
Species Problem ◽  
Comprehensive Review ◽  
Volvocine Algae ◽  
Cryptic Taxa

More than ten new species of colonial volvocine algae were described in world literature during recent years. In present review, the published data on taxonomy, geographical distribution and the species problem in this group of algae, mainly from the genera Gonium, Pandorina, Eudorina, and Volvox, are critically discussed. There are both cosmopolitan volvocalean species and species with local or disjunct distribution. On the other hand, the description of new cryptic taxa in some genera of the colonial family Volvocaceae, such as Pandorina and Volvox, complicates the preparation of a comprehensive review on their geography.

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