Abstract: A method of producing lactic acid by continuous fermentation includes filtering a culture of polyploidy prototrophic yeast having a capacity to produce lactic acid by introduction of a lactate dehydrogenase gene through a porous membrane having an average pore size of not less than 0.01 ?m and less than 1 ?m; and recovering the lactic acid from filtrate while the unfiltered liquid is retained in or returned to the culture and a fermentation feedstock is added to the culture.

Abstract: A method of producing cadaverine is more efficient and at a higher yield than production methods by the conventional fermentation methods. The method includes culturing coryneform bacterium/bacteria having a resistance to a pH of 5.5 or less. Preferably, the coryneform bacterium/bacteria has/have lysine decarboxylase activity and, preferably, the coryneform bacterium/bacteria has/have homoserine auxotrophy and/or a resistance to S-(2-aminoethyl)-L-cysteine.

Abstract: A method produces a chemical through continuous fermentation including: (a) culturing a cell in a culture medium in a fermentor to ferment a feedstock to produce a chemical; (b) conducting filtration of the culture medium with a separation membrane module; (c) separating a permeate containing the chemical from the culture medium while retaining a non-permeated liquid in the fermentor, and (d) supplying a gas from at least one of a lower portion of the separation membrane module and a pipe communicating between the fermentor and the separation membrane module to adjust a gas linear velocity in the separation membrane module to 0.15 cm/s to 70 cm/s while supplying the separation membrane module with a liquid.

Abstract: A method produces cadaverine more efficiently and at a higher yield than production methods by the conventional fermentation methods. The method includes culturing coryneform bacterium/bacteria having an ability to produce cadaverine and having a resistance to 2,2?-thiobis(ethylamine). Preferably, the coryneform bacterium/bacteria has/have lysine decarboxylase activity and, preferably, the coryneform bacterium/bacteria has/have homoserine auxotrophy and/or a resistance to S-(2-aminoethyl)-L-cysteine.

Abstract: A method of producing lactic acid continuous fermentation including filtering a culture of polyploid yeast having a capacity to produce lactic acid through a porous membrane having an average pore size of not less than 0.01 ?m and less than 1 ?m, and recovering the product from the filtrate while the unfiltered liquid is retained in or returned to the culture and a fermentation feedstock is added to the culture.

Abstract: By a method for producing cadaverine by culturing a microorganism that extracellularly secretes lysine decarboxylase, by-production of lysine is suppressed, the yield of cadaverine relative to glucose consumption is improved compared to conventional production methods, and further, the load on the purification step in purification of cadaverine as a raw material for polyamide can be reduced.

Abstract: A method of producing 1,5-pentanediamine includes culturing coryneform bacterium having a gene encoding lysine decarboxylase in its chromosome, which coryneform bacterium maintains lysine decarboxylase activity of not less than 50 mU/mg protein during culturing and the gene encoding lysine decarboxylase is linked downstream of a promoter that functions during the logarithmic growth phase.

Abstract: A method for producing a diamine includes purifying a diamine from an aqueous solution containing a diamine salt by adding an alkaline substance to the aqueous solution and then filtering the resulting solution by allowing the solution to pass through a nanofiltration membrane to remove the salt, thereby obtaining an aqueous diamine solution.

Abstract: A hollow fiber membrane module for use in production of a chemical substance, which is used in continuous fermentation including filtering a fermentation broth of a microorganism or a cultured cell through a hollow fiber membrane, collecting a chemical substance from a filtrate, retaining a concentrated solution in the fermentation broth or refluxing the concentrated solution, and adding a fermentation raw material to the fermentation broth, wherein a large number of hollow fiber membrane bundles are accommodated in a tubular case, at least one end part of each of the bundles is fixed on the tubular case by a hollow fiber membrane bundling member with an end face of each of the hollow fiber membranes open, and the hollow fiber membrane bundling member is made of a synthetic resin having a hardness retention rate after contact with saturated steam at 121° C. for 24 hours of 95% or more.

Abstract: Lactic acid is obtained by a method including (A) a step of continuous fermentation wherein a fermentation culture medium of a microorganism having an ability of lactic acid fermentation is filtered through a porous membrane having an average pore size of not less than 0.01 ?m and less than 1 ?m with a transmembrane pressure difference within the range of 0.1 to 20 kPa, and the permeate is collected, while retaining the non-permeated liquid in or returning the non-permeated liquid to the culture, and adding a fermentation feedstock to the culture; (B) a step of filtering the permeate obtained in Step (A) through a nanofiltration membrane; and (C) a step of distilling the permeate obtained in Step (B) under a pressure of not less than 1 Pa and not more than atmospheric pressure, at 25° C. to 200° C. to recover lactic acid.

Abstract: To control flow velocity of a culture liquid inside a membrane separation tank without giving influences to culture conditions in the fermentation tank, and also suppress precipitation of microorganisms or culture cells so that the production efficiency of the chemical product can be improved, in a method for producing a chemical product including the steps of: cultivating microorganisms or culture cells in a fermentation tank; transferring a culture liquid from the fermentation tank to a membrane separation tank so as to filter the culture liquid through a separation membrane; and collecting a fermentation product from a filtration liquid as the chemical product while refluxing an unfiltered culture liquid that has not been filtered so as to be joined to the culture liquid on an upstream side of the membrane separation tank, one portion of the culture liquid to be transferred from the fermentation tank is allowed to bypass the membrane separation tank depending on a pressure at the culture liquid flow-in sid

Abstract: A method of producing lactic acid continuous fermentation including filtering a culture of polyploid yeast having a capacity to produce lactic acid through a porous membrane having an average pore size of not less than 0.01 ?m and less than 1 ?m, and recovering the product from the filtrate while the unfiltered liquid is retained in or returned to the culture and a fermentation feedstock is added to the culture.

Abstract: A method for producing a diamine includes purifying a diamine from an aqueous solution containing a diamine salt by adding an alkaline substance to the aqueous solution and then filtering the resulting solution by allowing the solution to pass through a nanofiltration membrane to remove the salt, thereby obtaining an aqueous diamine solution.

Abstract: The invention provides a method of producing a chemical product through continuous fermentation which includes filtering a culture of a microorganism or cultured cells with a separation membrane to recover a product from a filtrate and simultaneously retaining a nonfiltered fluid in, or refluxing it to, the culture, and adding fermentation materials to the culture, wherein a porous membrane having an average pore size of 0.01 ?m or more to less than 1 ?m is used as the separation membrane and the filtration is conducted with a transmembrane pressure difference in the range of 0.1 to 20 kPa. According to this method, the fermentation productivity of the chemical product can be largely elevated at high stability and a low cost.

Abstract: A method for producing D-lactic acid in high yield, and to provide a method for producing D-lactic acid with high selectivity, in which optical purity is high and a by-product organic acid is small. In one aspect, a microorganism, wherein activity of pyruvate formate-lyase (pfl) is inactivated or decreased, and further activity of Escherichia coli-derived NADH-dependent D-lactate dehydrogenase (ldhA) is enhanced, is cultured to efficiently produce D-lactic acid. With regard to a method for enhancing ldhA activity, by linking, on a genome, a gene encoding ldhA with a promoter of a gene which controls expression of a protein involved in a glycolytic pathway, a nucleic acid biosynthesis pathway or an amino acid biosynthesis pathway, suitable results are obtained compared to the method for enhancing expression of the gene using an expression vector.