Komagataeibacter intermedius V-05: An Acetic Acid Bacterium Isolated from Vinegar Industry, with High Capacity for Bacterial Cellulose Production in Soybean Molasses-Based Medium

Research background. Despite the great properties of bacterial cellulose, its manufacture is still limited due to difficulties in production at large-scale. These problems are mainly related to low production yields and high overall costs of the conventional culture media normally used. Reversing these problems makes it necessary to identify new cheap and sustainable carbon sources. Thus, this work aimed to isolate and select a high cellulose-producing Komagataeibacter strain from vinegar industry, and study their potential for bacterial cellulose synthesis in an industrial soybean co-product, known as soybean molasses, to be used as fermentation medium. Experimental approach. For one isolated strain that exhibited high level of cellulose production in the standard Hestrin-Schramm medium, the ability of this biopolymer production in a soybean molasses-based medium was determined. The produced membranes were characterized by thermogravimetric analysis, X-ray diffraction, infrared spectroscopy, water holding capacity and rehydration ratio for determination of its characteristics and properties. The selected strain was also characterized by genetic analysis for determination of its genus and specie. Results and conclusions. An isolated strain was genetically identified as Komagataeibacter intermedius V-05 and exhibited the highest cellulose production in Hestrin-Schramm medium (3.7 g/L). In addition, the production by this strain in soybean molasses-based medium was 10.0 g/L. Membranes from both substrates were similar in terms of chemical structure, crystallinity and thermal degradation. Soybean molasses proved to be a suitable alternative medium for biosynthesis of cellulose in comparison with standard medium. In addition to providing higher production yield, the membranes showed great structural characteristics, similar to those obtained from standard medium. Novelty and scientific contribution. In this research, we have isolated and identified a Komagataeibacter strain which exhibits a high capacity for cellulose production in soybean molasses medium. The isolation and selection of strains with high capacity of microbial metabolites production is important for decreasing bioprocess costs. Furthermore, as there is a necessity today to find cheaper carbon sources that provide microbial products at a lower cost, soybean molasses represents an interesting alternative medium to produce bacterial cellulose prior to its industrial application.