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 Acetobacter pasteurianus 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. A. pasteurianus 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.