Implementation of Adaptive Evolution in Lactic Acid Bacteria to Enhance Yoghurt Cultures for the Dairy Industry

Sara Abril Niño, Anna Sofía Roncancio Tocancipa, María Paula Deaza-Fernández, Gabriela Rabe Caez, Alejandro Acosta González, Juan David Fierro Garavito*

PUBLISHED IN – 1st International Online Conference on Innovations in Food Science and Technology „INNOFOOD 2025”

Keywords: strain improvement, yoghurt production, adaptive evolution.

Abstract:

The dairy industry faces the challenge of reducing energy consumption while extending product shelf life. This project seeks to improve the genetics of Streptococcus thermophilus using non-transgenic methodologies based on biological evolution. Although Lactobacillus bulgaricus was used in yoghurt production, the results focused on S. thermophilus as the primary model. The engineering team was responsible for the genetic modification process, while practical validation was carried out in the culinary field (by gastronomists).

Gastronomists were responsible for propagating, inoculating, and fermenting experimental yoghurts derived from S. thermophilus strains. Subsequently, physicochemical analyses (reducing sugars, proteins, pH, and syneresis), microbiological evaluations, and preliminary sensory tests were performed. The study aimed to compare yoghurts made with improved strains to commercial ones, focusing on the performance of the different strains.

A progressive decrease in pH was observed, attributable to increased lactic acid production in the modified strains K1, K3, and G6, with higher acidification and sugar consumption rates than the wild-type strains and those obtained through mutagenesis. At the microbiological level, higher counts of lactic acid bacteria and lower residual lactose concentrations were observed, while fungal, yeast, and coliform tests indicated safety throughout fermentation. In terms of syneresis, no differences were observed among strains. The yoghurt base exhibited an average syneresis of 11.2%, yielding about 112 g/L.

In conclusion, gastronomic validation is a fundamental step in translating biotechnological advances into practical food applications. This collaborative work demonstrated that the modified S. thermophilus strains are comparable to commercial yoghurts only at the scale-up stage. However, during fermentation, they offer significant time advantages; thus, this comparison ensures a product with consumer-recognisable attributes. The gastronomic contribution, in collaboration with engineering, ensured that the technological innovation was evaluated against production realities and the direct sensory experience of food.

DOI:

*Grupo de Investigación en Alimentación, Gestión de Procesos y Servicio, Escuela Internacional de Ciencias Económicas y Administrativas, Universidad de La Sabana.

Grupo de Investigación en procesos agroindustriales (GIPA), Facultad de Ingeniería, Universidad de La Sabana.

Grupo de Investigación en Bioprospección (GIBP), Facultad de Ingeniería, Universidad de La Sabana.

Universidad de La Sabana, Maestría en Diseño y Gestión de Procesos.

Unisabana Center for Translational Sciences, Universidad de La Sabana.