Abstract: A method of producing a fine fiber, including treating a cellulose raw material with an enzyme; and fibrillating the treated cellulose raw material; treating with the enzyme under a condition where at least a ratio of endo-glucanase activity to cellobiohydrolase activity that is 0.06 or greater. The cellulose raw material may be a plant fiber. The method efficiently produces a fine fiber from a cellulose raw material at low cost and with a low environmental burden, a fine fiber, and a non-woven fabric.

Abstract: A method of producing a fine fiber, including treating a cellulose raw material with an enzyme; and fibrillating the treated cellulose raw material; treating with the enzyme under a condition where at least a ratio of endo-glucanase activity to cellobiohydrolase activity that is 0.06 or greater. The cellulose raw material may be a plant fiber. The method efficiently produces a fine fiber from a cellulose raw material at low cost and with a low environmental burden, a fine fiber, and a non-woven fabric.

Abstract: A method for the enzymatic saccharification of a lignocellulosic raw material, including adding a pretreated lignocellulosic raw material as a material suitable for an enzymatic saccharification reaction, together with an electrolyte containing a water-soluble salt, to water that contains a celluolose saccharification enzyme; saccharifying the raw material by an enzymatic saccharification reaction, as a suspension of the raw material having an electrical conductivity adjusted to 5-25 mS/cm; separating and recovering a reaction product and an enzyme-containing solution from the enzymatically saccharified treatment suspension; and recycling the recovered enzyme-containing solution as the enzyme for the enzymatic saccharification step.

Abstract: A method for the enzymatic saccharification of a lignocellulosic raw material, including adding a pretreated lignocellulosic raw material as a material suitable for an enzymatic saccharification reaction, together with an electrolyte containing a water-soluble salt, to water that contains a celluolose saccharification enzyme; saccharifying the raw material by an enzymatic saccharification reaction, as a suspension of the raw material having an electrical conductivity adjusted to 5-25 mS/cm; separating and recovering a reaction product and an enzyme-containing solution from the enzymatically saccharified treatment suspension; and recycling the recovered enzyme-containing solution as the enzyme for the enzymatic saccharification step.

Abstract: The present invention provides a pretreatment method which enables the promotion of the enzymatic glycosylation of lignocellulose under relatively mild conditions by using a tree bark as a raw material with less energy. Specifically the present invention provides a step for producing a sugar from a tree bark, which is characterized by having the following steps: an alkali treatment step of immersing the tree bark in an alkali compound solution; a refining treatment step of refining the alkali treated tree bark mechanically into fine pieces; and an enzymatic glycosylation step of glycosylating the refined tree bark with an enzyme. The present invention also provides a method of producing an ethanol.