African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5128

Full Length Research Paper

Isolation of a Lactobacillus strain from aguamiel and preliminary characterization of its antimicrobial components

Benítez-Serrano Juan Carlos
  • Benítez-Serrano Juan Carlos
  • Laboratorio de Microbiología Aplicada, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, México.
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Martínez-Pérez Laura
  • Martínez-Pérez Laura
  • Laboratorio de Microbiología Aplicada, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, México.
  • Google Scholar
Rosas-Murrieta Nora Hilda
  • Rosas-Murrieta Nora Hilda
  • Laboratorio de Bioquímica, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, México.
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Brambila-Colombres Eduardo Miguel
  • Brambila-Colombres Eduardo Miguel
  • Laboratorio de Investigaciones Químico Clínicas, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, México.
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Hernández-Castro Rigoberto
  • Hernández-Castro Rigoberto
  • Departamento de Ecología y Agentes Patógenos, Hospital General Manuel Gea González, Ciudad de México, México.
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Rosales-Pérez Mónica
  • Rosales-Pérez Mónica
  • Instituto Tecnológico de Estudios Superiores de Monterrey, Campus Puebla, México.
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Aguilar-Alonso Patricia
  • Aguilar-Alonso Patricia
  • Laboratorio de Investigaciones Químico Clínicas, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, México.
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  •  Received: 08 May 2018
  •  Accepted: 29 June 2018
  •  Published: 14 August 2018

Abstract

The aim of the study was to characterize the antimicrobial components of Lactobacillus paracasei KSI.  In the study, a L. paracasei KSI strain was isolated and identified from aguamiel using a 16S rRNA, hsp, recA and rpoBgenes sequencing. The antimicrobial capacity of the L. paracasei strain KSI was determined by agar double layer diffusion technique, while the antagonistic activity of the cell-free extract (E-KSI) was evaluated by agar well diffusion method against different bacterial strains; it demonstrated a wide spectrum of inhibition. Likewise, E-KSI showed stability at different temperatures and digestive enzymes; its activity was lost at pH>5. Subsequently, E-KSI was concentrated (10x) by evaporation increasing its antagonistic effect. Antagonism tests by thin-layer chromatography (TLC)–bioautography of the E-KSI 10x showed the presence of more than one active substances different from lactic acid, possibly of the bacteriocin type. Some of these substances were recovered by extractions with ethyl ether, ethyl acetate and n-butanol respectively. Finally, we evaluated them using antagonism tests by minimum inhibitory concentration (MIC) and microdilution. L. paracaseistrain KSI generates substances with antibacterial activity having a wide spectrum of inhibition; it is a promising alternative to future biotechnological applications. The strain of L. paracasei KSI as well as the antimicrobial components that it generates has important antagonistic properties, making them an interesting biotechnological alternative to be used as probiotic or a safe functional food.

 

Key words: Lactobacillus, antimicrobials, probiotics, biotechnology, food safety.