Kinetic analysis of growth of Lactobacillus delbrueckii subsp. bulgaricus WDCM 00102 in algae-based medium

Abstract

An unstructured mathematical model is proposed to describe the fermentation kinetics of growth, lactic acid production, pH and sugar consumption by Lactobacillus delbrueckii subsp. bulgaricus WDCM 00102 (National Bank for Industrial Microorganisms and Cell Cultures, Sofia, Bulgaria) as a function of the buffering capacity and initial dry matter concentration of pretreated biomass of Spirulina platensis (Arthrospira platensis) ('Simbiotex' Ltd., Sofia, Bulgaria) in the culture media. Initially the experimental data of L. delbrueckii subsp. bulgaricus WDCM 00102 fermentations in algae-based media with different buffering capacities and dry matter concentrations were fitted to a set of primary models. Later the parameters obtained from these models were used to establish mathematical relationships with the independent variables tested. The models were validated with 6 fermentations of L. delbrueckii subsp. bulgaricus WDCM 00102 in different algae-based media. In most cases, the proposed models adequately describe the biochemical changes taking place during fermentation and are a promising approach for the formulation of algae-based probiotic foods.