Abstract: The invention relates to the directed evolution of CYP52A12 gene and the use thereof for the production of a dicarboxylic acid. In particular, it relates to a method of preparing a long chain dicarboxylic acid producing strain by using directed evolution and homologous recombination, a strain obtained by the method that is capable of producing a long chain dicarboxylic acid under an acidic condition and the use thereof. In particular, the invention relates to a method of preparing a long chain dicarboxylic acid producing strain by directed evolution of CYP52A12 gene and homologous recombination, a strain obtained by the method that is capable of producing a long chain dicarboxylic acid under an acidic condition and the use thereof. By directed evolution of CYP52A12 gene, one strain which has a base mutation at the promoter region of said gene and is capable of producing a long chain dicarboxylic acid under an acidic condition in a shortened fermentation time is screened out in the invention.

Abstract: The present invention discloses a method for producing a long chain dicarboxylic acid by fermentation as well as a fermentation broth, a treated fermentation broth and a wastewater. The salt content in the fermentation broth is controlled to be below 20% by the fermentation method of the present invention. The method for producing a long chain dicarboxylic acid by fermentation provided by the present invention can effectively reduce the amount of alkali used in the fermentation process and the amount of acid used in the subsequent extraction of the long chain dicarboxylic acid, thereby reducing the amount of salt in the whole production process of the long chain dicarboxylic acid. At the same time, the method of the present invention also has many advantages such as shortening the fermentation time, increasing the acid production, reducing the amount of medium, and suitable for the production of various types of long-chain dicarboxylic acids, etc.

Abstract: The present disclosure provides a method for isolating a long chain dicarboxylic acid from fermentation broth containing microbial cells. Also provided is a substantially pure long chain dicarboxylic acid isolated by the method.

Abstract: One aspect of the present disclosure relates to a stabilized recombinant expression plasmid vector comprising a polynucleotide encoding an antitoxin gene which expresses a polypeptide that neutralizes a polypeptide toxic to a host cell, the toxic polypeptide being expressed by a toxin gene in the host cell, and a polynucleotide encoding a polypeptide expression product, and the stabilized recombinant expression plasmid vector is derived from a Hafnia alvei autonomously replicable backbone plasmid. Other aspects of the present disclosure relate to a transformant transformed with the stabilized recombinant expression plasmid vector disclosed herein, a method of producing biobased cadaverine using the transformant disclosed herein, and biobased cadaverine prepared by the method disclosed herein. Another aspect of the present disclosure relates to a polyamide formed using biobased cadaverine disclosed herein, and a composition thereof.

Abstract: Provided is a method for extracting a 1,5-pentanediamine from a solution system containing a 1,5-pentanediamine salt. The method comprises adding to the solution system an insoluble basic substance to form a solution system containing free 1,5-pentanediamine. The provided method has high applicability, is easy to use, and is environmentally-friendly, significantly lowering raw material costs and operating costs for the entire manufacturing process. The method achieves a high recovery rate for pentanediamine, and is more suitable for industrial-scale production.

Abstract: The present invention provides a decanedioic acid produced by microbial fermentation process, in which the content of C10 aliphatic acid and C10 hydroxy aliphatic acid is maintained at a very low level. The present invention also provides a preparation method of the decanedioic acid and a polymer prepared by using the decanedioic acid as monomer. The decanedioic acid provided by the present invention is prepared by microbial fermentation process. The decanedioic acid product which is produced through the processes of microbial fermentation and separation has a higher purity, a higher thermal stability, and a lower impurity content. The decanedioic acid provided by the present invention could satisfy the requirements of high grade product of polyamide or polyester to produce polymer with excellent qualities.

Abstract: Provided are microorganisms genetically modified to overexpress porin polypeptides to enhance the production of lysine and lysine derivatives by the microorganism. Also provided are methods of generating such microorganism, and methods of producing lysine and lysine derivatives using the genetically modified microorganisms.

Abstract: Provided are lysine decarboxylase polypeptides comprising mutants of SEQ ID NO: 2 and/or fragments thereof. The mutants or fragments have at least 95% sequence identity with SEQ ID NO: 2. Also provided are DNA polynucleotides encoding said lysine decarboxylases, expression vector comprising the DNA polynucleotides, transformants, mutant host cells, methods for the production of lysine decarboxylases, and methods for the production of a lysine-derived product.

Abstract: The present invention relates to a method for the purification of cadaverine from an aqueous cadaverine salt composition comprising one or more involatile impurities, the method comprising: (1) mixing the aqueous cadaverine salt composition with one or more bases to provide an aqueous cadaverine composition having a pH of at least about 12; (2) distilling or evaporating the aqueous cadaverine composition to produce an aqueous cadaverine solution, wherein one or more solvents are added to the evaporation/distillation system before the evaporation/distillation stops, and the one or more solvents comprise at least one or more high boiling point (HBP) solvents having a boiling point of at least 185° C. (1 atm); and (3) subjecting the aqueous cadaverine solution to one or more rectification steps to provide a cadaverine product.

Abstract: The present invention provides a mutant polypeptide comprising the amino acid sequence of Escherichia coli tetracycline efflux pump A (TetA), and a polynucleotide encoding the polypeptide. The present invention provides a first expression plasmid vector comprising one or more first polynucleotides encoding a tetracycline efflux pump, one or more second polynucleotides independently selected from the group consisting of a third polynucleotides encoding a lysine decarboxylase polypeptide and a fourth polynucleotides encoding a lysine biosynthesis polypeptide, and a transformant comprising the expression plasmid vector. The present invention provides a host cell comprising one or more first, third or fourth polynucleotides as described herein integrated into a chromosome of the host cell. The present invention also provides a method for producing a lysine of a cadaverine using the transformant and/or the host cell.

Abstract: The invention relates to a method for preparing cadaverine comprising: (1) obtaining an aqueous cadaverine salt composition from a fermentation system; (2) adjusting the pH of the aqueous cadaverine salt composition to a pH of at least about 12 by adding an inorganic base composition to provide a first composition comprising an aqueous cadaverine composition having a pH of at least about 12 and a solid composition comprising one or more alkali metal sulfates; (3) subjecting the first composition to solid-liquid separation without organic solvent extraction to provide the aqueous cadaverine composition and the solid composition; (4) distilling or evaporating the aqueous cadaverine composition of step (3) without organic solvent extraction to provide purified cadaverine; (5) preparing a saturated solution of the alkali metal sulfate(s) from the solid composition of step (3) at a temperature of about 35-40° C.

Abstract: The present invention relates to a method for the purification of cadaverine from an aqueous cadaverine salt composition comprising one or more involatile impurities, the method comprising: (1) mixing the aqueous cadaverine salt composition with one or more bases selected from the group consisting of Ca(OH)2, Mg(OH)2, CaO and MgO to provide an aqueous cadaverine composition; and (2) distilling or evaporating the aqueous cadaverine composition to produce purified cadaverine; wherein one or more solvents are added to the evaporation/distillation system before the evaporation/distillation stops, and the one or more solvents comprise at least one or more high boiling point (HBP) solvents.

Abstract: One aspect of the invention relates to a method for the purification of cadaverine from an aqueous cadaverine composition comprising one or more involatile impurities, the method comprising: a) distilling or evaporating the aqueous cadaverine composition wherein one or more solvents are added to the evaporation/distillation system before the evaporation/distillation starts, during the evaporation/distillation and/or after the evaporation/distillation substantially stops when no more evaporation/distillation is observed to produce purified cadaverine, wherein the evaporation or distillation is done at a heating temperature of about 80° C. to about 180° C. and under a pressure of 1 atm or lower, and the one or more solvents comprise at least one or more high boiling point (HBP) solvents having a boiling point of at least about 185° C. (1 atm); and b) recovering the one or more HBP solvents.

Abstract: Provided is a method for purifying 1,5-pentanediamine comprising: providing 1,5-pentanediamine to be purified and treating the 1,5-pentanediamine to be purified by a reduction reaction to obtain purified 1,5-pentanediamine. Meanwhile, further provided is 1,5-pentanediamine prepared by the method. The purification method has a concise process and a simple operation, and is suitable for industrial production, and can significantly improve the quality of 1,5-pentanediamine.

Abstract: Provided are a lysine decarboxylase immobilized cell and preparation method thereof.

Abstract: The present invention provides a method for preparing nylon salt, which comprises mixing 1,5-pentanediamine, water and dicarboxylic acid at a temperature of 65 to 120° C. to obtain a nylon salt, wherein the amount of the water is 2% to 12% by weight based on the total weight of the 1,5-pentanediamine and the dicarboxylic acid. The present invention also provides a nylon salt. According to the present method for preparing nylon salt, the incomplete reaction between the 1,5-pentanediamine and the dicarboxylic acid, which is caused by the nylon salt present during the preparation in a solid state, can be avoided; the reaction between the 1,5-pentanediamine and the dicarboxylic acid can be significantly speeded up, and the reaction time is accordingly shorten. Consequently, the content of diamine and dicarboxylic acid remained in the resulting nylon salt is very low. In addition, the final nylon salt product, which present in a solid state, makes it easier to be stored and transported.

Abstract: The expression plasmid vectors comprise a polynucleotide sequence encoding Ldc2 polypeptide, a fragment, and/or a mutant. A backbone plasmid is capable of autonomous replication in a host cell. The host cell is not a P. aeruginosa cell. Transformants are transformed with expression plasmid vector. The transformants are not P. aeruginosa. Mutant host cells comprise a polynucleotide sequence encoding Ldc2 polypeptide, a fragment and/or a mutant that has been integrated into the host cell chromosome. A polypeptide, a fragment and/or a mutant comprise Ldc2. A non-naturally occurring polynucleotide, and/or a mutant encodes polypeptide comprising Ldc2. Biobased cadaverine is produced using the transformants and the biobased cadaverine is prepared by the method. Polyamides are formed using the biobased cadaverine and compositions.

Abstract: The present invention relates to a method for the purification of cadaverine from an aqueous cadaverine salt composition comprising one or more involatile impurities, the method comprising: (1) mixing the aqueous cadaverine salt composition with one or more bases selected from the group consisting of Ca(OH)2, Mg(OH)2, CaO and MgO to provide an aqueous cadaverine composition; and (2) distilling or evaporating the aqueous cadaverine composition to produce purified cadaverine; wherein one or more solvents are added to the evaporation/distillation system before the evaporation/distillation stops, and the one or more solvents comprise at least one or more high boiling point (HBP) solvents.

Abstract: One aspect of the invention relates to a method for the purification of cadaverine from an aqueous cadaverine composition comprising one or more involatile impurities, the method comprising: a) distilling or evaporating the aqueous cadaverine composition wherein one or more solvents are added to the evaporation/distillation system before the evaporation/distillation starts, during the evaporation/distillation and/or after the evaporation/distillation substantially stops when no more evaporation/distillation is observed to produce purified cadaverine, wherein the evaporation or distillation is done at a heating temperature of about 80° C. to about 180° C. and under a pressure of 1 atm or lower, and the one or more solvents comprise at least one or more high boiling point (HBP) solvents having a boiling point of at least about 185° C. (1 atm); and b) recovering the one or more HBP solvents.

Abstract: Disclosed is a process for treating a reaction solution containing a long chain dicarboxylate. The process is characterized by comprising: acidifying a reaction solution so as to convert the long chain dicarboxylate into a long chain dicarboxylic acid, adding an extractant so as to extract the resulting long chain dicarboxylic acid, separating the phase rich in the long chain dicarboxylic acid, and further separating the long chain dicarboxylic acid. The process of the present invention has the following advantages: 1) the processing route is simple, the operation time is short, less equipment is required, and the production efficiency is high; 2) product yield is high; 3) product quality is good, purity in the resulting products is high, and the color is lighter; and 4) no active carbon is consumed and the solvent can be recycled, thereby saving resources and being environmentally friendly.