Microcultures of lactic acid bacteria: characterization and selection of strains, optimization of nutrients and gallic acid concentration

  • Oswaldo Guzmán-López
  • Octavio Loera
  • José Luis Parada
  • Alberto Castillo-Morales
  • Cándida Martínez-Ramírez
  • Christopher Augur
  • Isabelle Gaime-Perraud
  • Gerardo Saucedo-Castañeda
Original Paper

Abstract

Eighteen lactic acid bacteria (LAB) strains, isolated from coffee pulp silages were characterized according to both growth and gallic acid (GA) consumption. Prussian blue method was adapted to 96-well microplates to quantify GA in LAB microcultures. Normalized data of growth and GA consumption were used to characterize strains into four phenotypes. A number of 5 LAB strains showed more than 60% of tolerance to GA at 2 g/l; whereas at 10 g/l GA growth inhibition was detected to a different extent depending on each strain, although GA consumption was observed in seven studied strains (>60%). Lactobacillus plantarum L-08 was selected for further studies based on its capacity to degrade GA at 10 g/l (97%). MRS broth and GA concentrations were varied to study the effect on growth of LAB. Cell density and growth rate were optimized by response surface methodology and kinetic analysis. Maximum growth was attained after 7.5 h of cultivation, with a dilution factor of 1–1/2 and a GA concentration between 0.625 and 2.5 g/l. Results indicated that the main factor affecting LAB growth was GA concentration. The main contribution of this study was to propose a novel adaptation of a methodology to characterize and select LAB strains with detoxifying potential of simple phenolics based on GA consumption and tolerance. In addition, the methodology presented in this study integrated the well-known RSM with an experimental design based on successive dilutions.

Keywords

Lactic acid bacteria Gallic acid Microculture Prussian blue method Response surface methodology 

Abbreviations

GA

Gallic acid

HPLC

High performance liquid chromatography

LAB

Lactic acid bacteria

MRS

Man Rogosa and Sharpe

OD

Optical density

PC

Phenolic compounds

RSM

Response surface methodology

X1

Dilution factor

X2

Gallic acid concentration

X1

Coded dilution factor, −log2(X1)

X2

Coded GA, −log2(X2/10)

Copyright information

© Society for Industrial Microbiology 2008

Authors and Affiliations

  • Oswaldo Guzmán-López
    • 1
  • Octavio Loera
    • 1
  • José Luis Parada
    • 1
  • Alberto Castillo-Morales
    • 2
  • Cándida Martínez-Ramírez
    • 1
  • Christopher Augur
    • 3
  • Isabelle Gaime-Perraud
    • 3
  • Gerardo Saucedo-Castañeda
    • 1
  1. 1.Department of BiotechnologyMetropolitan Autonomous University (UAM), Campus IztapalapaMexico D.F.Mexico
  2. 2.Department of MathematicsMetropolitan Autonomous University (UAM), Campus IztapalapaMexico D.F.Mexico
  3. 3.IRD-Unité BioTransIMEP UMR IRD 193, Boîte 441, Faculty of Science and Technology St. Jérôme, Université Paul CézanneMarseille Cedex 20France

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