title: Antimicrobial compounds produced by Lactobacillus sakei subsp.  sakei 2a, a bacteriocinogenic strain isolated from a Brazilian meat  product.
abstract: Bacteriocins produced by lactic acid bacteria are gaining increased importance due to their activity against undesirable microorganisms in foods. In this study, a concentrated acid extract of a culture of Lactobacillus sakei subsp. sakei 2a, a bacteriocinogenic strain isolated from a Brazilian pork product, was purified by cation exchange and reversed-phase chromatographic methods. The amino acid sequences of the active antimicrobial compounds determined by Edman degradation were compared to known protein sequences using the BLAST-P software. Three different antimicrobial compounds were obtained, P1, P2 and P3, and mass spectrometry indicated molecular masses of 4.4, 6.8 and 9.5 kDa, respectively. P1 corresponds to classical sakacin P, P2 is identical to the 30S ribosomal protein S21 of L. sakei subsp. sakei 23 K, and P3 is identical to a histone-like DNA-binding protein HV produced by L. sakei subsp. sakei 23 K. Total genomic DNA was extracted and used as target DNA for PCR amplification of the genes sak, lis and his involved in the synthesis of P1, P2 and P3. The fragments were cloned in pET28b expression vector and the resulting plasmids transformed in E. coli KRX competent cells. The transformants were active against Listeria monocytogenes, indicating that the activity of the classical sakacin P produced by L. sakei 2a can be complemented by other antimicrobial proteins.
authors.affiliation: Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Avenida Professor Lineu Prestes, 580, Cidade Universitária, P. O. Box 05508-900, São Paulo, SP, Brazil. ka20_04@hotmail.com
authors.forename: Kátia G
authors.initials: KG
authors.lastname: de Carvalho
authors.forename: Felipe H S
authors.initials: FH
authors.lastname: Bambirra
authors.forename: Monika F
authors.initials: MF
authors.lastname: Kruger
authors.forename: Matheus S
authors.initials: MS
authors.lastname: Barbosa
authors.forename: Jamil S
authors.initials: JS
authors.lastname: Oliveira
authors.forename: Alexandre M C
authors.initials: AM
authors.lastname: Santos
authors.forename: Jacques R
authors.initials: JR
authors.lastname: Nicoli
authors.forename: Marcelo P
authors.initials: MP
authors.lastname: Bemquerer
authors.forename: Antonio
authors.initials: A
authors.lastname: de Miranda
authors.forename: Emiliano J
authors.initials: EJ
authors.lastname: Salvucci
authors.forename: Fernando J M
authors.initials: FJ
authors.lastname: Sesma
authors.forename: Bernadette D G M
authors.initials: BD
authors.lastname: Franco
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001430:Bacteriocins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001938:Brazil; D002853:Chromatography, Liquid / Q000379:methods; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D007778:Lactobacillus / Q000302:isolation & purification / Q000378:metabolism*; D013058:Mass Spectrometry; D008461:Meat Products / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D008970:Molecular Weight; D010957:Plasmids; D016133:Polymerase Chain Reaction; D020539:Sequence Analysis, Protein
chemical_list: D000890:Anti-Infective Agents; D001430:Bacteriocins; D004269:DNA, Bacterial