Sulfur-Containing Compounds in Cellulose Hydrolysis

The patent applies preliminary action by adding sulfur dioxide or sulfur-containing compounds at the beginning of the enzymatic hydrolysis process to prevent contamination before it occurs. The sulfur dioxide is introduced in the pretreatment or initial hydrolysis stage to create an antimicrobial environment that deters bacterial and yeast growth throughout the extended hydrolysis period, thereby protecting the glucose production process without requiring separate sterilization steps.

The patent applies parameter changes by using sulfur dioxide to modify the chemical environment during hydrolysis rather than severely treating the cellulose structure itself. The sulfur dioxide creates a more reactive and accessible cellulose state through mild chemical interaction, improving enzyme accessibility and hydrolysis efficiency while maintaining the structural integrity of cellulose and preserving hemicellulose and lignin yields, thus avoiding the harsh effects of severe chemical pretreatment.

The patent converts the harmful effect of extended hydrolysis time (which normally increases contamination risk) into a benefit by using sulfur dioxide to create an antimicrobial environment. The long hydrolysis duration required for complete cellulose conversion is maintained to achieve high glucose yields, while the sulfur dioxide simultaneously prevents contamination throughout this extended period, effectively converting the time-related contamination risk into a controlled process where completeness is achieved without penalty.