The role of two families of bacterial enzymes in putrescine synthesis from agmatine via agmatine deiminase

Putrescine, one of the main biogenic amines associated to microbial food spoilage, can be formed by bacteriafrom arginine via ornithine decarboxylase (ODC), or from agmatine via agmatine deiminase (AgDI). This study aims to correlate putrescine production from agmatine to the pathway involving N-carbamoylputrescine formation via AdDI (the aguAproduct) and N-carbamoylputrescine amidohydrolase (the aguB product), or putrescine carbamoyltransferase (the ptcA product) in bacteria. PCR methods were developed to detect the two genes involved in putrescine production from agmatine.Putrescine production from agmatine could be linked to the  aguA and  ptcA genes in  Lactobacillus hilgardii X1B,Enterococcus faecalis ATCC 11700, and Bacillus cereus ATCC 14579. By contrast Lactobacillus sakei 23K was unable toproduce putrescine, and although a fragment of DNA corresponding to the gene aguA was amplified, no amplification wasobserved for the ptcA gene. Pseudomonasaeruginosa PAO1 produces putrescine and is reported to harbour aguA and aguBgenes, responsible for agmatine deiminase and N-carbamoylputrescine amidohydrolase activities. The enzyme from P. aeruginosa PAO1 that converts N-carbamoylputrescine to putrescine (the aguB product) is different from other microorganismsstudied (the ptcA product). Therefore, the aguB gene from P. aeruginosa PAO1 could not be amplified with ptcA specificprimers. The aguB and ptcA genes have frequently been erroneously annotated in the past, as in fact these two enzymes areneither homologous nor analogous. Furthermore, the aguA, aguB and ptcA sequences available from GenBank were subjected to phylogenetic analysis, revealing that gram-positive bacteria harboured ptcA, whereas gram-negative bacteria harbouraguB. This paper also discusses the role of the agmatine deiminase system (AgDS) in acid stress resistance.&nbsp

A proteolytic effect of Oenococcus oeni on the nitrogenous macromolecular fraction of red wine

The proteolytic activity of Oenococcus oeni protease on the release of individual amino acids and peptides from a red wine macromolecular nitrogenous fraction was evaluated. 148.7 mg l(-1) of individual amino acids were released and a difference of 109.5 mg l(-1) with respect to the amino acids liberation from white wine was observed. Stimulatory amino acids for O. oeni growth, glutamic acid and proline, were the most important amino acids obtained by the protease activity. In the HPLC and spectral analysis of peptides before and after the protease activity of O. oeni, several changes have been observed. Three new peaks, six higher and one lower have been found in the chromatogram obtained after the enzyme action. The specific activity of O. oeni protease is higher on the red than on the white wine proteins and this is important considering the lower protein concentration in red wine. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.This work was carried out in the framework of the Iberoamerican Cooperation Program from the Spanish Ministerio de Educación y Cultura. The authors thank the ¢nancial support given by CIUNT and CONICET, Argentina and the Comisión Interministerial de Ciencia y Tecnología (Project ALI97-0630)España.Peer reviewe

Utilization of amino acids and dipeptides by Lactobacillus plantarum from orange in nutritionally stressed conditions

To investigate amino acid and dipeptide utilization by Lactobacillus plantarum N4 isolated from orange peel, in a nutritionally depleted medium basedon MRS (Mann, Rogosa, Sharpe).Methods and Results: In MRS with 0 Æ1 g l)1 of meat extract and without peptone and yeast extract, growth increased when essential and stimulatory amino acids and nonessential amino acid were added to the medium. Replacement of the essential amino acid, leucine, and the nonessential amino acid, glycine, byleucyl-leucine (Leu-Leu) and ⁄or glycyl-glycine (Gly-Gly) significantly enhancedgrowth. Essential amino acids were mainly consumed and the dipeptides were almost completely used at the end of growth. Leucine and glycine accumulatedinternally from the peptides were higher than from the free amino acids.Glucose utilization increased in the media containing dipeptides comparedwith the medium containing free amino acids.Conclusions: In a N-depleted medium, Leu-Leu and ⁄or Gly-Gly were more effective than the respective amino acids in supporting growth of the microorganism. The more efficient internal accumulation of glycine and especially leucine from dipeptides confirmed the ability of the strain to assimilate mainly complex nitrogen molecules rather than simple ones.Significance and Impact of the Study: The ability of Lact. plantarum N4 to efficiently use dipeptides could contribute to spoilage development in the natural medium of the organism, orange juiceFil: Saguir de Zucal, Fabiana Maria. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Loto Campos, Iris Eleonora. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaFil: Manca de Nadra, M. C.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

The role of two families of bacterial enzymes in putrescine synthesis from agmatine via agmatine deiminase

Putrescine, one of the main biogenic amines associated to microbial food spoilage, can be formed by bacteria from arginine via ornithine decarboxylase (ODC), or from agmatine via agmatine deiminase (AgDI). This study aims to correlate putrescine production from agmatine to the pathway involving N-carbamoylputrescine formation via AdDI (the aguA product) and N-carbamoylputrescine amidohydrolase (the aguB product), or putrescine carbamoyltransferase (the ptcA product) in bacteria. PCR methods were developed to detect the two genes involved in putrescine production from agmatine. Putrescine production from agmatine could be linked to the aguA and ptcA genes in Lactobacillus hilgardii X1B, Enterococcus faecalis ATCC 11700, and Bacillus cereus ATCC 14579. By contrast Lactobacillus sakei 23K was unable to produce putrescine, and although a fragment of DNA corresponding to the gene aguA was amplified, no amplification was observed for the ptcA gene. Pseudomonas aeruginosa PAO1 produces putrescine and is reported to harbour aguA and aguB genes, responsible for agmatine deiminase and N-carbamoylputrescine amidohydrolase activities. The enzyme from P. aeruginosa PAO1 that converts N-carbamoylputrescine to putrescine (the aguB product) is different from other microorganisms studied (the ptcA product). Therefore, the aguB gene from P. aeruginosa PAO1 could not be amplified with ptcA-specific primers. The aguB and ptcA genes have frequently been erroneously annotated in the past, as in fact these two enzymes are neither homologous nor analogous. Furthermore, the aguA, aguB and ptcA sequences available from GenBank were subjected to phylogenetic analysis, revealing that gram-positive bacteria harboured ptcA, whereas gram-negative bacteria harbour aguB. This paper also discusses the role of the agmatine deiminase system (AgDS) in acid stress resistance.Fil: Landete, José M.. Universidad de Valencia; EspañaFil: Arena, Mario Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; ArgentinaFil: Pardo, Isabel. Universidad de Valencia; EspañaFil: Manca de Nadra, María C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; ArgentinaFil: Ferrer, Sergi. Universidad de Valencia; Españ