Antimicrobial compounds produced by Lactobacillus sakei subsp. sakei 2a, a bacteriocinogenic strain isolated from a Brazilian meat product

DE CARVALHO, KG; BAMBIRRA, FHS; KRUGER, MF; BARBOSA, MS; OLIVEIRA, JS; SANTOS, AMC; NICOLI, JR; BEMQUERER, MP; DE MIRANDA, A; SALVUCCI, E; SESMA, FJM; FRANCO, BDGM

JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY

Blackwell

Lugar: Berlin / Heidelberg; Año: 2010 vol. 37 p. 381 - 390

1367-5435

Bacteriocins produced by lactic acid bacteriaare gaining increased importance due to their activityagainst undesirable microorganisms in foods. In this study,a concentrated acid extract of a culture of Lactobacillussakei subsp. sakei 2a, a bacteriocinogenic strain isolatedfrom a Brazilian pork product, was purified by cationexchange and reversed-phase chromatographic methods.The amino acid sequences of the active antimicrobialcompounds determined by Edman degradation were comparedto known protein sequences using the BLAST-Psoftware. Three different antimicrobial compounds wereobtained, P1, P2 and P3, and mass spectrometry indicatedmolecular masses of 4.4, 6.8 and 9.5 kDa, respectively. P1corresponds to classical sakacin P, P2 is identical to the30S ribosomal protein S21 of L. sakei subsp. sakei 23 K,and P3 is identical to a histone-like DNA-binding proteinHV produced by L. sakei subsp. sakei 23 K. Total genomicDNA was extracted and used as target DNA for PCRamplification of the genes sak, lis and his involved in thesynthesis of P1, P2 and P3. The fragments were cloned inpET28b expression vector and the resulting plasmidstransformed in E. coli KRX competent cells. The transformantswere active against Listeria monocytogenes,indicating that the activity of the classical sakacin P producedby L. sakei 2a can be complemented by other antimicrobialproteins.