Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.7.1.2 (nitrate reductase)
 3,861 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of bacteria in the production of non volatile and volatile compounds involved in the fermented meat flavour is discussed. Lactic acid bacteria produce D-lactic and acetic acids which may give a sour note. By reducing the pH, they also modulate the other bio-chemical bacterial activities. In muscle tissue proteins are degraded into peptides and lipids into fatty acids mainly by endogenous enzymes. In fermented meat products with a high pH lipases from very lipolytic species of Staphylococcus could increase lipolysis. Bacteria could also play a role in the production and degradation of free amino acids. Staphylococcus and to a lesser extent, lactic acid bacteria could participate in the production of methyl-branched aldehydes and their corresponding alcohols and acids from branchedchain amino acids. By their nitrate reductase and catalase Staphylococcus species limit fatty acid oxidation and aldehyde production. Staphylococcus could contribute to the ester content as they can produce or hydrolyse esters in vitro.
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PMID:Bacterial role in flavour development. 2206 Jul 4

Lactic acid bacteria (LAB) from traditional fermented sausages of the Basilicata region were investigated by ARDRA-PCR and RAPD-PCR for taxonomic identification at species and strain level and characterized on the basis of the growth and acidification at different temperatures, incubation times, levels of NaCl and KNO(2), hydrolysis of sarcoplasmatic and myofibrillar proteins and antimicrobial, peptide/amino acid release and nitrate reductase activities. Lactobacillus sakei was the predominant species (67%) followed by Pediococcus pentosaceus (16%), Leuconostoc carnosum (8%), Lactobacillus plantarum (4%), Lactobacillus brevis (2%) and Leuconostoc pseudomesenteroides (2%). The technological characterization revealed that most of the isolates had good acidifying and proteolytic properties. Moreover, Lb. sakei strains showed antimicrobial ability, while Leuconostoc strains the highest reduction of nitrates. This work was a preliminary study in the formulation of autochthonous starter cultures in order to standardize the production process of sausages, to preserve their typical organoleptic and sensory characteristics and to improve the quality of final product.
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PMID:Molecular and technological characterization of lactic acid bacteria from traditional fermented sausages of Basilicata region (Southern Italy). 2206 64

Lactic acid bacteria (LAB) from raw and fermented pork samples were screened for their inhibitory activity by an agar spot test in order to obtain a LAB strain with suitable property to be used as meat starter cultures. Among the 174 isolates, 73 were positive to inhibit at least one of the seven indicator bacteria, which were further characterized. The most suitable isolate was isolate P0805, identified as Pediococcus pentosaceus. This bacterium was catalase- and nitrate reductase-positive and amino acid decarboxylase-negative; moreover, it produced inhibitory substances against Salmonella Typhimurium with the activity of the partially purified inhibitory substances of 409,600 AU/mL. To further characterize the catalase-producing ability of P. pentosaceus P0805, the effect of hematin on its catalase activity in Sausage Model Broth (SMB) was evaluated, and it enhanced catalase production. The catalase activity was found in both SMB with and without hematin. It was concluded that catalase produced by this bacterium was heme-independent catalase.
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PMID:Lactic acid bacteria isolated from raw and fermented pork products: Identification and characterization of catalase-producing Pediococcus pentosaceus. 3026 25