| 摘要 |
PROBLEM TO BE SOLVED: To provide: a method for removing bacterial contaminants from a saccharified solution, whereby it becomes possible to prevent the proliferation of bacteria in a fermentation vessel without requiring the use of an antibiotic in the alcoholic fermentation of a biomass saccharified solution using the conventional yeast; and a fermentation system which is suitable for the implementation of such method for removing bacterial contaminants from a saccharified solution.SOLUTION: Rough separation is carried out for withdrawing a saccharified solution (a fermentation solution) out of a fermentation vessel and then collecting yeast from the saccharified solution. Subsequently, fine separation is carried out for removing the bacterial contaminants from the saccharified solution from which the yeast has been separated out. Thus only the bacterial contaminants can be removed from the saccharified solution while collecting the yeast. The rough separation is carried out by the membrane filtration using a filtration membrane having a pore size of 0.5 to 5 μm inclusive or the centrifugation at 50 to 500 G inclusive. The fine separation is carried out by the membrane filtration using a filtration membrane having a pore size of 0.22 μm or less or the centrifugation at 1,000 to 15,000 G inclusive. |
