Global Regulation of the Response to Sulfur Availability in the Cheese-Related Bacterium Brevibacterium aurantiacum

INRA-AgroParis Tech, UMR 782 Génie et Microbiologie des Procédés Alimentaires, Centre de Biotechnologies Agro-Industrielles, 78850 Thiverval-Grignon, France.
Applied and Environmental Microbiology (Impact Factor: 3.67). 02/2011; 77(4):1449-59. DOI: 10.1128/AEM.01708-10
Source: PubMed


In this study, we combined metabolic reconstruction, growth assays, and metabolome and transcriptome analyses to obtain a
global view of the sulfur metabolic network and of the response to sulfur availability in Brevibacterium aurantiacum. In agreement with the growth of B. aurantiacum in the presence of sulfate and cystine, the metabolic reconstruction showed the presence of a sulfate assimilation pathway,
thiolation pathways that produce cysteine (cysE and cysK) or homocysteine (metX and metY) from sulfide, at least one gene of the transsulfuration pathway (aecD), and genes encoding three MetE-type methionine synthases. We also compared the expression profiles of B. aurantiacum ATCC 9175 during sulfur starvation or in the presence of sulfate. Under sulfur starvation, 690 genes, including 21 genes
involved in sulfur metabolism and 29 genes encoding amino acids and peptide transporters, were differentially expressed. We
also investigated changes in pools of sulfur-containing metabolites and in expression profiles after growth in the presence
of sulfate, cystine, or methionine plus cystine. The expression of genes involved in sulfate assimilation and cysteine synthesis
was repressed in the presence of cystine, whereas the expression of metX, metY, metE1, metE2, and BL613, encoding a probable cystathionine-γ-synthase, decreased in the presence of methionine. We identified three ABC transporters:
two operons encoding transporters were transcribed more strongly during cysteine limitation, and one was transcribed more
strongly during methionine depletion. Finally, the expression of genes encoding a methionine γ-lyase (BL929) and a methionine transporter (metPS) was induced in the presence of methionine in conjunction with a significant increase in volatile sulfur compound production.

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Available from: Isabelle Martin-Verstraete
    • "e (SEQMU2_13200) and two gènes encoding a cystathionine gamma-lyase (SEQMU2_13205 and SEQMU2_10740) are présent. Study of thé génome of B. aurantiacum ATCC 9174 revealed thé présence of gènes encoding a L-methionine-gamma-lyase, a cystathionine beta-lyase, and a gène encoding either a second cystathionine beta-lyase or a cystathionine gamma-lyase (Forquin étal. 2011)."
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    ABSTRACT: Cheese organisms are derived from the dairy environment, from humans and from the environment. Milk and its evolution provide the selective environment for growth of cheese organisms but salt is the major additional selective pressure imposed upon the smear cheese surface. Perhaps the evolutionary history of the actinobacterial phylogenetic clade as “Terrabacter” and selection for resistance to desiccation on aerobic surfaces has provided species able to exploit these environments. But human selection over the history of cheese-making may have selected cheese-microorganism consortia adapted to produce desirable cheese properties, including the ability to outgrow contaminating microorganisms on the cheese-surface and modify the organoleptic properties. The properties of some of the characteristic cheese-related organisms relevant to cheese such as iron availability, catabolism, bacteriocins, osmotolerance and proteolysis of casein are described and compared to related species from other environmental habitats from a genomics perspective.
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    • "were found on the cheeses from the farmhouses (dairies A, B and C). B. linens and B. aurantiacum, found on the cheeses from dairies B and C, respectively, have been used for a long time as ripening cultures by the dairy industry [16], whereas the soil bacteria B. permense found on the cheese from dairy A, to our knowledge, has not previously been found on cheese. "
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