Microbial Interactions between Amylolytic and Non-Amylolytic Lactic Acid Bacteria Strains Isolated during the...

Area of Science:

• Food Microbiology
• Fermentation Science
• Applied Microbiology

Background:

• Pozol is a traditional Mexican fermented maize beverage with complex microbial ecology.
• Understanding the interactions of lactic acid bacteria (LAB) is key to optimizing pozol fermentation.

Purpose of the Study:

• To investigate the effects of inoculating pozol LAB strains (amylolytic *Sii*-25124 and non-amylolytic *W. confusa* 17) in pure and mixed cultures.
• To compare these effects with a known amylolytic strain, *L. plantarum* A6, on fermentation parameters.

Main Methods:

• Pure and mixed cultures of selected LAB strains were grown on MRS-starch medium.
• Key parameters measured included microbial growth, kinetic parameters, amylolytic activity, lactic acid production, and starch hydrolysis products.
• Population dynamics were monitored using quantitative polymerase chain reaction (qPCR).

Main Results:

• *L. plantarum* A6 exhibited superior enzymatic activity, lactic acid, and biomass production in pure culture compared to pozol LAB.
• Co-culturing pozol LAB with *L. plantarum* A6 led to reduced amylolytic activity, lactic acid yield, growth rate, and amylase production.
• The interaction between *Sii*-25124 and *W. confusa* 17 significantly increased specific growth rate, lactic acid yield, and production rate by 15-40% compared to *Sii*-25124 alone.

Conclusions:

• Interactions between *Sii*-25124 and *W. confusa* 17 are vital for enhancing pozol fermentation parameters.
• Co-culturing strategies can be employed to optimize the production of fermented maize beverages like pozol.