Response surface methodology-based improvement of the yield and differentiation of properties of bacterial cellulose by metabolic enhancers

• Published in: International journal of biological macromolecules Vol. 187; pp. 584 - 593
• Main Authors: Cielecka, Izabela, Ryngajłło, Małgorzata, Maniukiewicz, Waldemar, Bielecki, Stanisław
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 30-09-2021
• Subjects: Acetic Acid - metabolism; Bacterial nanocellulose; Cellulose - biosynthesis; Cellulose - chemistry; Crystallization; Elastic Modulus; Ethanol - pharmacology; Gluconacetobacter xylinus - drug effects; Gluconacetobacter xylinus - growth & development; Gluconacetobacter xylinus - metabolism; Gluconates - metabolism; Glucose - metabolism; Hydrogen-Ion Concentration; Lactic Acid - pharmacology; Metabolic enhancers; Response surface methodology; Tensile Strength; Water - chemistry; Metabolic enhancers; Bacterial nanocellulose; Response surface methodology
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2021.07.147

This study aims to examine the effect of ethanol and lactic acid on the production of bacterial cellulose, and determine the optimal composition of a co-supplemented culture using response surface methodology. Both ethanol and lactic acid, when added separately or jointly, affected the yield and properties of the biomaterial. Optimization resulted in an increase of 470% in the yield, compared to the Schramm-Hestrin medium. Culture growth profiles, substrate consumption and by-products generation, were examined. The growth rate was increased for cultures supplemented with lactic acid and both lactic acid and ethanol, while the production of gluconic acid was diminished for all modified cultures. The properties of BNC, such as the structure, crystallinity, water holding capacity and tensile strength, were also determined. BNC produced in optimal conditions is more porous and characterized by wider fibers. Despite a decrease in crystallinity, by the addition of ethanol, lactic acid and both additives, the ratio of cellulose Iα was almost unchanged. The stress, strain, young modulus and toughness were improved 2.8-4.2 times, 1–1.9 times, 2.4-3.5 times and 2.5-6.8 times, respectively. The new approach to improving BNC yields and properties presented here could contribute to more economical production and wider application of this biopolymer.
•Ethanol and lactic acid influences the metabolism of K. xylinus E25.•Either ethanol or lactic acid improves the yield of bacterial cellulose.•Optimization of the co-supplemented medium enhances the yield by 470%.•The mechanical properties of BNC produced in the modified media were improved.•Physical properties of BNC differ significantly in dependence on culture condition.