Isolation of a New Acetobacter pasteurianus Strain from Spontaneous Wine Fermentations and Evaluation of Its Bacterial Cellulose Production Capacity on Natural Agrifood Sidestreams

A bacterial cellulose (BC) producing bacterial species was isolated from spontaneous wine fermentations and identified as <i>Acetobacter pasteurianus</i> and assigned the strain designation ABBA. The strain had the ability to synthesize BC in orange juice, achieving a yield of 5.0 g/L. Further production optimization was studied using a non-fortified natural substrate composed of substandard raisin extracts, orange juice, and green tea extract. The Response Surface Methodology for the production design and optimization was applied, resulting in a significantly higher yield of up to 15.5 g/L. The porosity, crystallinity, and antioxidant activity of the produced BC films were affected by both the BC drying method and the substrate used. In the FT-IR spectra, characteristic peaks corresponding to citric acid, gallic acid, ascorbic acid and thiamine were observed, indicating their adsorption onto the BC matrix and explaining the increased antioxidant activity. <i>A. pasteurianus</i> ABBA is a promising new strain that can be used in the production of BC from agrifood sidestreams (substandard raisins; discarded oranges), contributing to their utilization and the production of value-added materials within a circular-economy framework.