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.

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 Proteome Mining of Sortase A Dependent Proteins (SDPs) in Lactic Acid Bacteria and Docking Analysis of SDPs Interaction with Sortase A

2020 ◽  
Author(s):  
Nahid Javanshir ◽  
Ehsaneh Moslem Rezvani ◽  
Zakie Mazhary ◽  
Sepideh Razani ◽  
Gholamreza Ahmadian ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Binding Energy ◽  
Lactic Acid Bacteria ◽  
Surface Proteins ◽  
Sortase A ◽  
Bacterial Surface ◽  
Lpxtg Motif ◽  
Host Interaction

Abstract Background: Lactic acid bacteria (LAB), which are important probiotics, play a fundamental role in ensuring the health of the gastrointestinal tract, maintaining the microbiome balance, and preventing the gastrointestinal (GI) tract disorder. One of the effective mechanisms in the bacterial-host interaction is related to the action of the enzyme sortase A and Sortase Dependent Proteins (SDPs). Sortase plays an important role in the stabilization and retention of the probiotic in the gut by exposing various SDPs on the bacterial surface proteins which is involved in the attachment of bacteria to the host intestine and retention in the gut.Methods: The present study aimes to identify and investigate the abundance of sortase A-dependent proteins (SDPs) in lactic acide bacteria, as well as the frequency analysis of X residue in the sortase recognition and cleavage LPXTG motif and its effect on the interaction between sortase and SDPs. For this purpose, genomic and proteomic sequences of 165 LABs including 119 Lactobacilli, 29 Enterococci, 8 Lactococci, 5 Carnobacteria, and 4 Leuconostocs, were extracted from UniProt and Genome NCBI databases,. for this, we designed ProtScreen software with the ability to recognize a specific motif and domain in the proteome, which is available at http://nigebprotscreen.com/. Also interactions between sortase A and LPXTG motif with 18 different amino acids in X position were determined using in silico approach. The structure of the sortase A enzyme and a SDP in Lactobacillus acidophilus was used for docking using HADDOCK and CABS-dock toolsResults: In this study, out of 165 LABs reference proteomes, there were 25 SDP-free strains. Among the 140 strains with SDPs, 707 proteins were found with the potential to function as SDPs. In this way, ProtScreen software with the ability to recognize a specific motif and domain in the proteome, which is available at http://nigebprotscreen.com/ was designed. Also a database including 707 SDPs in Lactobacillus, Enterococcus, Lactococcus, Carnobacterium, and Leuconostoc strains was designed which is available in the project section at online ProtScreen software. Our results showed that the most abundant amino acid in X position in the LPXTG motif among 165(LABs) is glutamine (Q). Results of SDPs and sortase A docking using HADDOCK and CABS-dock tools, showed that the highest binding energy is related to the glutamine, where a positive relationship between frequency of amino acids and binding energy was observed. Therefore, our data shows that why glutamine in nature and during evolution, has been selected as the best amino acid for X site in LPXTG motif.Conclusions: The results of the present research and similar studies could be useful in better understanding the role of sortase A and SDPs in the studies on the mechanisms related to the interactions between bacteria and the host, including longer probiotic persistence in the gut.

Effects of Inoculating Compound Lactic Acid Bacteria on the Quality of Cured Fish

2014 ◽  
Vol 685 ◽  
pp. 486-489 ◽  
Author(s):  
Yan Yan Wu ◽  
Gang You ◽  
Lai Hao Li ◽  
Xian Qing Yang ◽  
Ya Wei
Keyword(s):  
Lactic Acid ◽  
Amino Acid ◽  
Lactic Acid Bacteria ◽  
Nitrogen Content ◽  
Acid Content ◽  
Total Acid ◽  
Fish Quality ◽  
Salted Fish ◽  
Positive Effects ◽  
Amino Acid Nitrogen

Inoculation with compound lactobacillus in the low-salt pickled fish, fermented and dried to produce cured fish. The paper studied the effects of inoculating compound lactobacillus on the pH, total volatile basic nitrogen (TVB-N), amino acid nitrogen content (AA-N) and total acid content of salted fish quality. The results showed that, compared with the non-vaccinated groups (CK), The cured fish inoculated lactobacillus had a lower pH and TVB-N content, higher the amino acid nitrogen content and total acid content. Inoculated compound lactic acid bacteria into salted fish, to a certain extent, could improve the nutritional value and edible value, which had positive effects on the fish quality.

scholarly journals Effects of the Addition of Non-Starter Lactic Acid Bacteria on Free Amino Acid Production During Cheese Ripening

2018 ◽  
Vol 24 (2) ◽  
pp. 299-309 ◽  
Author(s):  
Risa Saiki ◽  
Tatsuro Hagi ◽  
Takumi Narita ◽  
Miho Kobayashi ◽  
Keisuke Sasaki ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Amino Acid ◽  
Lactic Acid Bacteria ◽  
Free Amino Acid ◽  
Acid Production ◽  
Free Amino ◽  
Amino Acid Production ◽  
Cheese Ripening

Seasonal variation in human amino acid excretion

1960 ◽  
Vol 15 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Henry B. Hale ◽  
James P. Ellis ◽  
Donald D. Van Fossan
Keyword(s):  
Amino Acids ◽  
Seasonal Variation ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Urine Volume ◽  
Urine Samples ◽  
Acid Excretion ◽  
Healthy Men ◽  
Significant Seasonal Variation ◽  
Sodium And Potassium

Amino acid excretion was studied in young, healthy men during summer, fall and winter months in a southwestern U. S. location. Both untimed and timed urine samples were employed. The amino acids determined were alanine, arginine, cysteine, glutamic acid, glutamine, glycine, histidine, lysine, methyl histidine, serine, threonine and valine. Supplemental determinations included urine volume, creatinine, uric acid, urea, sodium and potassium. Using untimed urine samples and expressing values as ratios with creatinine, significant seasonal variation was found for alanine, arginine, cysteine, glutamic acid, glycine, lysine and serine. Submitted on April 11, 1959

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