Optimizing the growth-associated β-galactosidase production by probiotic <i>Lactobacillus reuteri</i> B-14171: experimental design, culture medium volume increase, and cell growth modeling





Lactobacillus reuteri, β-galactosidase, optimization


This study reports an optimized culture medium in submerged cultivation to produce β-galactosidase by Lactobacillus reuteri. Four culture medium parameters were optimized (pH, lactose, casein, and inactive beer yeast), and the effect of different volumes of the optimized culture medium on the bioprocess was evaluated regarding β-galactosidase production. Different kinetic models were applied to predict enzymatic production as a function of biomass and substrate. It is the first time that both the effect of increasing the culture medium volume and mathematical modeling on the β-galactosidase production by L. reuteri have been studied. Besides, different bioprocess parameters were calculated based on the experimental data to verify the feasibility of enzymatic production. The achieved enzymatic activity for the optimized culture medium (12.75 g L-1 lactose; 1.88 g L-1 casein; 1.65 g L-1 inactive beer yeast and pH 5.61) resulted in an increase of 4.74-fold compared to the initial activity. Three culture medium volumes (200, 800, and 3,200 mL) were evaluated, and no significant difference was observed on maximum and total productivities (Pm and Pp), as well as on the product formation yield on biomass (YP/X). The Logistic model resulted in a good fit to the experimental data for all tested volumes, and the modified Luedeking-Piret model provided a satisfactory prediction of the enzymatic activity. The optimized culture medium reported in this work is an outstanding alternative to produce β-galactosidase by L. reuteri, which is microbial growth-associated, and the production was not affected by increasing the culture medium volume.

Biografia do Autor

Tatiane Aparecida Gomes, Federal University of Paraná

Graduação em Tecnologia em Alimentos (UTFPR, Ponta Grossa, 2010)

Mestrado em Ciência e Tecnologia de Alimentos (UEPG, Ponta Grossa, 2013)

Doutorado em Engenharia de Alimentos (UFPR, Curitiba, 2018)

Áreas de atuação: microbiologia, fermentação, produção de enzimas, uppstream.

Éliton Fontana, Federal University of Paraná (UFPR), 81530-900, Curitiba-Paraná, ,Brazil

Department of Chemical Engineering, Chemical Engineering

Acácio Antonio Ferreira Zielinski, Federal University of Santa Catarina (UFSC), 8040-970, Florianópolis-Santa Catarina, Brazil

Department of Chemical Engineering and Food Engineering, Food Engineering

Alessandro Nogueira, State University of Ponta Grossa (UEPG), 84030-900, Ponta Grossa-Paraná, Brazil

Graduate Program in Food Science and Technology, Food Science and Technology

Michele Rigon Spier, Federal University of Paraná (UFPR), 81530-900, Curitiba-Paraná, ,Brazil

Food Engineering Postgraduate Program, Department of Chemical Engineering, Food Engineering