Biochemical interactions between the symbionts of Convoluta roscoffensis

1975 ◽  
Vol 189 (1094) ◽  
pp. 121-135 ◽  
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Lactic Acid ◽  
Amino Acid ◽  
Glutamine Synthetase ◽  
Excess Oxygen ◽  
Convoluta Roscoffensis

Convoluta will slowly eject most of their algae if CO 2 is bubbled through their seawater media for a brief preliminary period. By means of this technique, it was shown that at least half of the carbon fixed in photosynthesis moved from alga to animal, possibly in the form of amino acids. Dichlorophenyldimethyl urea completely inhibits photosynthesis in intact worms, but causes no other immediate damage to the animals. No uric acid can be detected in healthy animals, but it accumulates after 2 weeks’ incubation in DCMU. Uricase and glutamine synthetase are both detectable in worms, and it is suggested that ammonia produced by uric acid catabolism in algae is assimilated into glutamine, which may be the main amino acid released back to the animal. If animals are first labelled with a pulse of 14 C through photosynthesis and then transferred to nonradioactive seawater containing 1 g/100 ml alanine, the amount of fixed 14 C released from worms is increased by darkness or DCMU treatment with much of the released 14 C appearing in lactic acid; these effects are largely abolished if excess oxygen is supplied to the worms. This suggests that photosynthetically produced oxygen may be utilized by animals, but since they survived 4 weeks in DCMU, it was clearly not essential.

scholarly journals Interrogation of the Perturbed Gut Microbiota in Gouty Arthritis Patients Through in silico Metabolic Modeling

2020 ◽  
Author(s):  
Michael A. Henson
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Amino Acid ◽  
Gut Microbiota ◽  
In Silico ◽  
Gouty Arthritis ◽  
Metabolic Modeling ◽  
Patient Specific ◽  
Surprising Result ◽  
Sulfur Containing

Recent studies have shown perturbed gut microbiota associated with gouty arthritis, a metabolic disease in which an imbalance between uric acid production and excretion leads to the deposition of uric acid crystals in joints. To mechanistically investigate altered microbiota metabolism in gout disease, 16S rRNA gene amplicon sequence data from stool samples of gout patients and healthy controls were computationally analyzed through bacterial community metabolic modeling. Patient-specific models were used to cluster samples according to their metabolic capabilities and to generate statistically significant partitioning of the samples into a Bacteroides-dominated, high gout cluster and a Faecalibacterium-elevated, low gout cluster. The high gout cluster samples were predicted to allow elevated synthesis of the amino acids D-alanine and L-alanine and byproducts of branched-chain amino acid catabolism, while the low gout cluster samples allowed higher production of butyrate, the sulfur-containing amino acids L-cysteine and L-methionine and the L-cysteine catabolic product H2S. The models predicted an important role for metabolite crossfeeding, including the exchange of acetate, D-lactate and succinate from Bacteroides to Faecalibacterium to allow higher butyrate production differences than would be expected based on taxa abundances in the two clusters. The surprising result that the high gout cluster could underproduce H2S despite having a higher abundance of H2S-synthesizing bacteria was rationalized by reduced L-cysteine production from Faecalibacterium in this cluster. Model predictions were not substantially altered by constraining uptake rates with different in silico diets, suggesting that sulfur-containing amino acid metabolism generally and H2S more specifically could be novel gout disease markers.

scholarly journals Impact of Short-term Artificial Low Salinity Stress on the Flavor Quality of Scylla Paramamosain

2021 ◽  
Vol 36 (2) ◽  
pp. 179-195
Author(s):  
Tu Chunfei ◽  
Li Xing ◽  
Wang Huan ◽  
Chen Yuhao ◽  
Liang Guoling ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Salinity Stress ◽  
Free Amino ◽  
Scylla Paramamosain ◽  
Low Salinity ◽  
Salinity Control ◽  
Cumulative Amount

Scylla paramamosain is a kind of large euryhaline marine crab. As an important physicochemical parameter of seawater, salinity has a great impact on the survival, growth and quality of Scylla paramamosain. This research tested the content of non-volatile flavor substance, lactic acid and taurine on the 0, 1st, 3rd, 7th and 15th day in three salinity gradients (3, 13, 23) with HPLC (High-performance Liquid Chromatography) technology. Results have shown that in low salinity stress, the cumulative amount of free amino acids in muscle of Scylla paramamosain is more than that in hepatopancreas, while the cumulative amount of essential amino acids in hepatopancreas is more than that in muscle. In muscle, contents of three flavor amino acids are ranked as follows: sweet, bitter and delicious amino acid, and in hepatopancreas, it is bitter, sweet and delicious amino acid. The fluctuation rule of free amino acid, essential amino acid and lactic acid in Scylla paramamosain in the low salinity group is similar to that of other salinity control group, while the content of sweet amino acid, bitter amino acid, nucleotide, EUC, taurine is different from that of other salinity control groups.

scholarly journals Poly(ester amide)s based on (L)-lactic acid oligomers and α-amino acids: influence of the α-amino acid side chain in the poly(ester amide)s properties

2013 ◽  
Vol 24 (12) ◽  
pp. 1391-1409 ◽  
Author(s):  
Ana C. Fonseca ◽  
Jorge F.J. Coelho ◽  
Joana F.A. Valente ◽  
Tiago R. Correia ◽  
Ilídio J. Correia ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Side Chain ◽  
Amino Acid Side Chain

scholarly journals Influence of D-Amino Acids in Beer on Formation of Uric Acid

2019 ◽  
Vol 57 (3) ◽  
pp. 418-425
Author(s):  
Yuhe Kan ◽  
Zhikun Zhang ◽  
Yujian He ◽  
Jingkui Yang ◽  
Li Wu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Amino Acid ◽  
High Risk ◽  
Biological Response ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Food Ingredients ◽  
Factors Affecting ◽  
Excessive Intake

Excessive intake of beer could increase serum uric acid levels, leading to high risk of gout, which was previously attributed to high purine content in beer. Recent reports that purine-rich vegetables and bean products do not cause higher uric acid levels do not support this theory. Why excessive intake of beer could increase a high risk of gout has been unclear. Other factors affecting the accumulation of uric acid in the blood have been explored. Beer contains relatively high levels of D-amino acids due to the racemization of L-amino acids induced by food processing. D-amino acid was catalyzed by D-amino acid oxidase to produce H2O2, which is further oxidized in the presence of Fe2+ to produce hydroxyl radicals, resulting in DNA damage and formation of a large amount of purine bases, which are oxidized to uric acid by a series of enzymes. Some food ingredients, such as vitamins and I–, prompt D-amino acids to form uric acid. D-amino acids in beer are one of the key factors responsible for the increase in uric acid levels. The biological response of D-amino acids could explain gout occurrence in beer drinkers.

scholarly journals Nitrogen and phosphorus required for the growth of phytoplankton

1940 ◽  
Vol 24 (1) ◽  
pp. 115-123 ◽  
Author(s):  
H. W. Harvey
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Amino Acid ◽  
Sea Water ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Communities ◽  
Bacterial Action

A method is described for obtaining growths of phytoplankton in samples of crude sea water, similar in composition but several hundred times more dense than phytoplankton communities occurring in the sea.The ratio of nitrogen to phosphorus utilized by such communities has been determined.They use ammonium in preference to nitrate, although the latter may be many times more concentrated than the former.They use urea and uric acid as sources of nitrogen.Certain amino-acids when added as sources of nitrogen were attacked by the bacteria in the community and either the ammonium set free or both the ammonium and the amino-acid were used by the phytoplankton. Others, as d-leucine, were not utilized, or, as l-leucine, only slowly utilized.Sodium nucleinate and caseinate were rapidly broken down when added to crude sea water by bacterial action, and the phosphate produced utilized by phytoplankton. There was no significant utilization of glycerophosphate.

scholarly journals Urate synthesis in the perfused chick liver

1974 ◽  
Vol 144 (2) ◽  
pp. 189-198 ◽  
Author(s):  
E Barratt ◽  
P J Buttery ◽  
K N Boorman
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Energy Consumption ◽  
Amino Acid ◽  
Perfused Liver ◽  
Perfusion Medium ◽  
Phosphoribosyl Pyrophosphate ◽  
Inosinic Acid ◽  
Ether Anaesthesia ◽  
Liver Preparation

Urate synthesis was studied in a perfused chicken liver preparation. The perfused liver had an ATP/ADP ratio of 0.29±0.05(6) compared with 0.34±0.07(10) in liver obtained from chicks under ether anaesthesia. Lactate/pyruvate ratios were 9.4±1.7(5) in the perfused liver and 14.8±1.8(5) in the rapidly sampled liver. Urate synthesis was only marginally stimulated by glycine, glutamine, aspartic acid or NH4Cl, but significant increases were observed with phosphoribosyl pyrophosphate, aminoimidazolecarboxylic acid riboside, inosine, inosinic acid and xanthine. Urate synthesis from glycine, glutamine, NH4Cl, asparagine, alanine, histidine and a mixture of 21 amino acids was obtained on inclusion of insulin in the perfusion medium. Evidence for the inclusion of the carbon of histidine into uric acid was obtained. Aspects of the energy consumption associated with the conversion of excess of amino acid into uric acid are considered.

scholarly journals Ability of Thermophilic Lactic Acid Bacteria To Produce Aroma Compounds from Amino Acids

2004 ◽  
Vol 70 (7) ◽  
pp. 3855-3861 ◽  
Author(s):  
Sandra Helinck ◽  
Dominique Le Bars ◽  
Daniel Moreau ◽  
Mireille Yvon
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Bacterial Species ◽  
Aroma Compounds ◽  
Lactobacillus Delbrueckii ◽  
Keto Acid ◽  
Amino Acid Catabolism ◽  
Catabolic Pathways ◽  
Keto Acids

ABSTRACT Although a large number of key odorants of Swiss-type cheese result from amino acid catabolism, the amino acid catabolic pathways in the bacteria present in these cheeses are not well known. In this study, we compared the in vitro abilities of Lactobacillus delbrueckii subsp. lactis, Lactobacillus helveticus, and Streptococcus thermophilus to produce aroma compounds from three amino acids, leucine, phenylalanine, and methionine, under mid-pH conditions of cheese ripening (pH 5.5), and we investigated the catabolic pathways used by these bacteria. In the three lactic acid bacterial species, amino acid catabolism was initiated by a transamination step, which requires the presence of an α-keto acid such as α-ketoglutarate (α-KG) as the amino group acceptor, and produced α-keto acids. Only S. thermophilus exhibited glutamate dehydrogenase activity, which produces α-KG from glutamate, and consequently only S. thermophilus was capable of catabolizing amino acids in the reaction medium without α-KG addition. In the presence of α-KG, lactobacilli produced much more varied aroma compounds such as acids, aldehydes, and alcohols than S. thermophilus, which mainly produced α-keto acids and a small amount of hydroxy acids and acids. L. helveticus mainly produced acids from phenylalanine and leucine, while L. delbrueckii subsp. lactis produced larger amounts of alcohols and/or aldehydes. Formation of aldehydes, alcohols, and acids from α-keto acids by L. delbrueckii subsp. lactis mainly results from the action of an α-keto acid decarboxylase, which produces aldehydes that are then oxidized or reduced to acids or alcohols. In contrast, the enzyme involved in the α-keto acid conversion to acids in L. helveticus and S. thermophilus is an α-keto acid dehydrogenase that produces acyl coenzymes A.

scholarly journals Phenotypic and Genotypic Analysis of Amino Acid Auxotrophy in Lactobacillus helveticus CNRZ 32

2007 ◽  
Vol 74 (2) ◽  
pp. 416-423 ◽  
Author(s):  
Jason K. Christiansen ◽  
Joanne E. Hughes ◽  
Dennis L. Welker ◽  
Beatriz T. Rodríguez ◽  
James L. Steele ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Lactic Acid Bacteria ◽  
Ornithine Decarboxylase ◽  
Lactobacillus Helveticus ◽  
Decarboxylase Activity ◽  
Biosynthetic Pathways ◽  
Ornithine Decarboxylase Activity ◽  
Genotypic Analysis

ABSTRACT The conversion of amino acids into volatile and nonvolatile compounds by lactic acid bacteria in cheese is thought to represent the rate-limiting step in the development of mature flavor and aroma. Because amino acid breakdown by microbes often entails the reversible action of enzymes involved in biosynthetic pathways, our group investigated the genetics of amino acid biosynthesis in Lactobacillus helveticus CNRZ 32, a commercial cheese flavor adjunct that reduces bitterness and intensifies flavor notes. Most lactic acid bacteria are auxotrophic for several amino acids, and L. helveticus CNRZ 32 requires 14 amino acids. The reconstruction of amino acid biosynthetic pathways from a draft-quality genome sequence for L. helveticus CNRZ 32 revealed that amino acid auxotrophy in this species was due primarily to gene absence rather than point mutations, insertions, or small deletions, with good agreement between gene content and phenotypic amino acid requirements. One exception involved the phenotypic requirement for Asp (or Asn), which genome predictions suggested could be alleviated by citrate catabolism. This prediction was confirmed by the growth of L. helveticus CNRZ 32 after the addition of citrate to a chemically defined medium that lacked Asp and Asn. Genome analysis also predicted that L. helveticus CNRZ 32 possessed ornithine decarboxylase activity and would therefore catalyze the conversion of ornithine to putrescine, a volatile biogenic amine. However, experiments to confirm ornithine decarboxylase activity in L. helveticus CNRZ 32 by the use of several methods were unsuccessful, which indicated that this bacterium likely does not contribute to putrescine production in cheese.

scholarly journals Overlapping Roles of Yeast Transporters Aqr1, Qdr2, and Qdr3 in Amino Acid Excretion and Cross-Feeding of Lactic Acid Bacteria

2021 ◽  
Vol 12 ◽  
Author(s):  
George C. Kapetanakis ◽  
Christos Gournas ◽  
Martine Prévost ◽  
Isabelle Georis ◽  
Bruno André
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Lactic Acid Bacteria ◽  
Binding Pocket ◽  
Acid Excretion ◽  
Yeast Mutant ◽  
Mutualistic Interaction ◽  
Metabolic States ◽  
Related Amino Acid

Microbial species occupying the same ecological niche or codeveloping during a fermentation process can exchange metabolites and mutualistically influence each other’s metabolic states. For instance, yeast can excrete amino acids, thereby cross-feeding lactic acid bacteria unable to grow without an external amino acid supply. The yeast membrane transporters involved in amino acid excretion remain poorly known. Using a yeast mutant overproducing and excreting threonine (Thr) and its precursor homoserine (Hom), we show that excretion of both amino acids involves the Aqr1, Qdr2, and Qdr3 proteins of the Drug H+-Antiporter Family (DHA1) family. We further investigated Aqr1 as a representative of these closely related amino acid exporters. In particular, structural modeling and molecular docking coupled to mutagenesis experiments and excretion assays enabled us to identify residues in the Aqr1 substrate-binding pocket that are crucial for Thr and/or Hom export. We then co-cultivated yeast and Lactobacillus fermentum in an amino-acid-free medium and found a yeast mutant lacking Aqr1, Qdr2, and Qdr3 to display a reduced ability to sustain the growth of this lactic acid bacterium, a phenotype not observed with strains lacking only one of these transporters. This study highlights the importance of yeast DHA1 transporters in amino acid excretion and mutualistic interaction with lactic acid bacteria.

Which Amino-Acids do Serum and Hemofiltrate of Critically Ill Patients with Acute Renal Failure Contain?

1997 ◽  
Vol 20 (6) ◽  
pp. 309-315 ◽  
Author(s):  
H-J. Guth ◽  
M. Wiersbitzky ◽  
M. Ziesche ◽  
H-J. Rose ◽  
G. Kraatz
Keyword(s):  
Amino Acids ◽  
Renal Failure ◽  
Acute Renal Failure ◽  
Lactic Acid ◽  
Amino Acid ◽  
Parenteral Nutrition ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Renal Replacement Therapies ◽  
Continuous Renal Replacement Therapies

The removal of amino acids during continuous renal replacement therapies induces clinical problems. Previous studies on animals have shown nephroprotective (glycine, alanine) or negative effects (lysine) on renal function in occurrence of acute renal failure. Disturbed metabolism in acute renal failure needs adequate parenteral nutrition. On the other hand, experience with continuous renal replacement therapies of metabolic crises in inborn errors of metabolism indicate a good control of disturbed amino acid metabolism. The aim of our study was to find amino acids, that might play an important role in the pathogenesis, prognosis and detection of acute renal failure and severe illness, so far only estimated by lactic acid. Thirty-three probes (serum and hemofiltrate) were taken from patients, suffering with acute renal failure caused by septic shock, severe pancreatitis and hepatorenal syndrome, one hour after the beginning of extracorporal circulation, the conditions of treatment were standardized. The material was deproteinized and studied by the amino acid analyzer LBK 4251 Apha Plus (Pharmacia, Stockholm, Sweden), while the lactic acid concentration was determined in a standard laboratory. Proline, glycine, alanine, methionine and histidine showed a close relationship to the lactic acid levels, but these amino acids were an essential part of parenteral nutrition. A statistical relationship was also established in (amino acids with amide groups) asparagine, glutamine, citrulline, cystathionine and phosphoethanolamine. The mean values of most of the amino acids were higher than normal, but standard deviations were increased. The presence of these amino acids in hemofiltrate and the good sieving coefficients could mean that the better prognosis of critically ill patients in continuous renal replacement therapies may also be due to continuous control of amino acid levels (especially with amide groups).

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