The current study intended to analyze the impact of ethanol and lactic acid on the bacterial cellulose yield as well as physicochemical and mechanical properties, by using Gluconacetobacter kombuchae. The optimization of ethanol and lactic acid concentration has been done by using one-way ANOVA. Both the supplements significantly enhance the yield of bacterial cellulose (BC) as compared to the standard Hestrin-Schramm medium (control). Optimization leads to significant increase in BC yield as compared to the control, i.e., the addition, of optimized concentration of lactic acid (0.6%) increases the yield from (0.78 ± 0.026) g to (4.89 ± 0.020) g dry weight, and optimized concentration of ethanol (1%) increases the yield from (0.73 ± 0.057) g to (3.7 ± 0.01) g dry weight. Various physicochemical and mechanical properties of BC films produced in different media (i.e., HS, HS + Ethanol, and HS + Lactic acid), such as the crystallinity, structure, tensile strength, strain at break, Young's modulus, and water holding capacity, were also examined, by employing various techniques such as SEM, FTIR, XRD, etc. BC produced in medium supplemented with the optimum concentration of both the additives were found to possesses higher porosity. Though, slight decline in crystallinity was observed. But the tensile strength and strain at break, were upgraded 1.5-2.5 times, 2-2.5 times, respectively. This article attempted to present a method for enhancing BC yields and characteristics that may lead to more widespread and cost-effective use of this biopolymer.
Keywords: Bacterial cellulose; ethanol; lactic acid; physicomechanical properties; supplementation; yield enhancement.