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

An unstructured mathematical model is proposed to describe the fermentation kinetics of growth, lactic acid production, pH and sugar consumption by<i>Lactobacillus delbrueckii subsp. bulgaricus WDCM 00102 </i>(National Bank for Industrial Microorganisms and Cell Cultures, Sofia, Bulgaria) asafunction ofthe buffering capacity and initial dry matter concentration ofpretreated biomass of<i>Spirulina platensis</i> (<i>Arthrospira platensis</i>) ('Simbiotex' Ltd., Sofia, Bulgaria) inthe culture media. Initially the experimental data ofL. <i>delbrueckii</i> subsp. <i>bulgaricus</i> WDCM 00102 fermentations inalgae-based media with different buffering capacities and dry matter concentrations were fitted toaset ofprimary models. Later the parameters obtained from these models were used toestablish mathematical relationships with the independent variables tested. The models were validated with 6 fermentations of<i>L.</i> <i>delbrueckii</i> subsp. <i>bulgaricus</i> 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.