METHOD FOR PRODUCING CHEMICALS BY CONTINUOUS FERMENTATION

摘要

Provided is a method for producing chemicals by continuous fermentation, in which a fermentation liquid containing fermentation starting materials, chemicals, and bacterial cells, microorganisms or culture cells is filtered using a separation membrane, the chemicals are recovered from the filtrate, the unfiltered liquid is retained with or refluxed to the fermentation liquid, and additional fermentation starting materials are added to the fermentation liquid. The separation membrane is a porous hollow-fiber membrane formed from polyvinylidene fluoride resin. High substance productivity of the method for producing chemicals by continuous fermentation is maintained by using a porous hollow-fiber membrane having an average pore diameter of 0.001 µm to 10.0 µm, a pure water permeation coefficient at 50 kPa and 25ºC of 0.5 m3/m2/hr to 15 m3/m2/hr, a rupture strength of 5 MPa to 20 MPa, a rupture elongation of 30% or greater but less than 200%, a degree of crimp of 1.3 to 2.5, a porosity of 40% or greater, and a critical surface tension of 45 mN/m to 75 mN/m.