Microbiota de fermentos naturais coletados em diferentes regiões climáticas do estado da Paraíba e seleção de leveduras de interesse para o mercado de panificação

Abstract

The final quality of the bread is influenced by the metabolic activity of the natural yeast microbiota, selected by adaptation to the conditions during the fermentation processes. The direct inoculation of pure cultures with desired properties allows greater control of the microbiota and, therefore, interest in its use has grown and requires a better understanding of the genetic and phenotypic diversity of strains for exploration in biotechnological processes. This innovative study aimed to characterize the microbial diversity of natural yeasts collected in the three different climatic regions of the state of Paraíba (humid, sub-humid and semi-arid) and evaluate the biotechnological viability of the yeasts isolated from these yeasts. 04 samples of natural yeast were collected, covering the 03 climatic regions of the state, represented by the municipalities of João Pessoa, Solânea and Cajazeiras, respectively. The BAL and yeast strains were isolated and identified by MALDI-TOF and the yeasts were subjected to the following biotechnological viability tests: sucrose fermentation with CO2 formation, acid formation, viability at different temperatures and in different concentrations of glucose and pH. 71 isolates were obtained, 40 of which were BAL and 31 were yeast. Of the bacteria, 05 different species were identified: L. plantarum (19 isolates), Levilactobacillus brevis (08 isolates), Companilactobacillus paralimentarius (07 isolates), Lacticaseibacillus paracasei (01 isolate) and B. cereus (05 isolates). Among the yeasts, the 31 isolates were identified as Saccharomyces cerevisiae and subjected to biotechnological viability tests, highlighting, from the Main Component Analysis (PCA), the strains S. cerevisiae 127 (Cajazeiras) and S. cerevisiae 57 (João Person B), regarding the formation of CO2, associated with growth viability at pH 3.5. Both strains were also identified by DNA sequencing using ITS marker amplicons as S. cerevisiae and were inoculated into fermented doughs to carry out fermentative activity tests: pH and acidity, BAL and yeast viability, determination of volume increase and properties of texture, during 24 hours of fermentation, showing a positive influence on the evaluated parameters, with emphasis on greater viability of S. cerevisiae 57 after 24 hours of fermentation. With the present study, it was possible to identify that the microbiota of natural yeasts collected in the state of Paraíba is characterized by the abundance of LAB in relation to yeasts and that there is a widespread presence of S. cerevisiae, with emphasis on the S. cerevisiae 127 strains ( Cajazeiras) and S. cerevisiae 57 (João Pessoa), with higher biotechnological quality for possible use as a starter culture.