Bacterial Cellulose Production: Decoupling Yield and Structural Quality in Refined and Waste-Derived Carbon Sources

Bacterial cellulose (BC) is a high-purity biopolymer with significant potential for sustainable material applications. However, its production remains limited by the metabolic behavior and compositional complexity of available carbon substrates. Simple sugars such as fructose, glucose, and sucrose support BC synthesis but differ in their metabolic pathways and associated byproduct formation, which can influence medium pH and cellulose biosynthesis. Across refined substrates, fructose generally outperforms glucose, producing the most favorable balance between productivity and structure. Reported fructose-based yields range from 1.55 to 6.29 g/L depending on the composition. In media containing hexoses, such as fructose, and three-carbon compounds, such as glycerol and pyruvate, biosynthesis proceeds via the pentose phosphate pathway. Additionally, pyruvate can be further metabolized via gluconeogenesis coupled with the tricarboxylic acid cycle, producing more BC precursors. In contrast, glucose-based yields are limited primarily by oxidation to gluconic acid, and sucrose often shows slower or lower initial production due to delayed metabolism, depending on the medium’s composition. Interestingly, structural trends showed that yield and structural quality are not always coupled. Fructose-based BC can reach around 90% to 92% crystallinity index (CrI) and is associated with lower porosity and larger nanoribbon networks, while sucrose-based BC can reach up to a 95.2% CrI despite slower initial production. Dual sugar systems further reveal differences in metabolism. Glucose-containing carbon sources are often suppressive because glucose dominates metabolism and acidification, whereas fructose-containing systems more often show synergistic behavior and support higher yields. Structural outcomes in these systems depend more on biosynthesis rates and strain-specific behavior than on carbon sources only. Additionally, low-cost substrates derived from agro-industrial residues and lignocellulosic biomass offer economically viable feedstock but introduce variability due to inhibitory compounds such as organic acids and phenolics. This review examines how sugar type and substrate complexity affect BC production and its structural properties in acetic acid bacteria, particularly the genera Acetobacter, Gluconacetobacter, and Komagataeibacter, with emphasis on the relationship between BC yield and CrI. Our analysis of the reported fermentation and characterization data in this review reveals a recurring paradox between yield and structural quality, in which substrates that promote higher BC yields do not always produce materials with superior structural properties such as crystallinity or degree of polymerization. Comparative examination of the literature revealed that inhibitory compounds such as phenolic compounds may act as structural modulators rather than simple yield suppressors. Phenolic compounds are predicted to bind to BC through non-covalent interactions facilitated by the large surface area and porous structure of BC. These interactions may influence the self-assembly of BC nanofibers. These findings indicate that fructose often offers the best balance of yield and structure. While sucrose tends to favor structural order, glucose is susceptible to yield loss from acidification, and waste-derived substrates can provide economic, high-yield, and structural properties only when their inhibitory compounds are well controlled.