Patents by Inventor Xiulai CHEN
Xiulai CHEN has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240132925Abstract: The invention provides a method for preparing pyrrolidone, and the invention provides a method for catalytically preparing pyrrolidone with ?-aminobutyric acid in the presence of carnitine-CoA ligase CaiC. The carnitine-CoA ligase CaiC has an amino acid sequence as shown in SEQ ID NO:1. The ligase has catalytic activity in the cyclization of ?-aminobutyric acid to produce pyrrolidone. The carnitine-CoA ligase provided in the present invention affords a yield of pyrrolidone of 3.26 g/L and a molar yield of 39.53% in 24 h when ?-aminobutyric acid is used as a substrate, thus reducing the production period, improving the production of pyrrolidone, and accelerating the industrialization process of producing pyrrolidone by enzymatic conversion method.Type: ApplicationFiled: October 18, 2022Publication date: April 25, 2024Inventors: Jing WU, Xuling JIANG, Liming LIU, Wei SONG, Yiwen ZHOU, Xiulai CHEN, LIU Jia, Cong GAO
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Publication number: 20240043884Abstract: The present invention provides recombinant Escherichia coli for producing glutarate, a construction method and use thereof. A double-plasmid recombinant bacterium is constructed through molecular biological means for co-expressing an aldehyde synthase (AAS) gene, an amine oxidase Mao (gene) and an aldehyde dehydrogenase (Glox) gene. The constructed expression plasmids are introduced into the Escherichia coli to reconstruct to obtain recombinant cells. A recombination strain for efficiently producing glutarate is obtained through amicillin resistance and kanamycin resistance combined plate screening. Efficient production of the glutarate is achieved by optimizing concentration of a substrate, cell concentration and a transformation temperature. L-lysine with a concentration of 30 g/L may be transformed into 19.Type: ApplicationFiled: December 3, 2021Publication date: February 8, 2024Inventors: Liming LIU, Zhilan ZHANG, Cong GAO, Xiulai CHEN, Liang GUO, Jia LIU, Wei SONG
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Publication number: 20230332190Abstract: The present invention relates to a recombinant strain for producing shikimic acid, in which a target gene that regulates the asymmetric cell division and target genes that regulate the shikimic acid production are expressed The target gene that regulates the asymmetric cell division includes cytoskeletal protein PopZ coding gene popZ, and the target genes that regulate the shikimic acid production include DAHP synthase coding gene aroG, 3-dehydroquinate synthase coding gene aroB, and transketolase coding gene tktA. The recombinant strain of the present invention realizes the de novo synthesis of shikimic acid using glucose as a substrate, with a low cost. After fermentation with the strain in a 7.5 L fermentor, the highest production of shikimic acid is 88.1 g/L, the yield is 0.33 g/g, and the production intensity of shikimic acid is 1.1 g/L/h.Type: ApplicationFiled: March 12, 2022Publication date: October 19, 2023Inventors: Liming LIU, Qiang DING, Xiulai CHEN, Cong GAO, Liang GUO, Guipeng HU, Jia LIU
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Patent number: 11781118Abstract: The disclosure discloses preparation of an L-amino acid deaminase mutant and application thereof, belonging to the technical field of gene engineering. Through pmirLAAD protein modification, analysis of a flexible loop structure around a binding site of the pmirLAAD product, and design of the best mutant, the modification method of the disclosure overcomes the defect that the catalytic efficiency of the previous wild-type enzyme is reduced due to product inhibition, and is tested by experiments. Compared with the control, the catalytic efficiency (1.61 mM?1·min?1) and the product inhibition constant (5.4 mM) of the finally obtained best mutant pmirLAADM4 are respectively increased by 5.2 times and 5.7 times. The yield of ?-ketoisovaleric acid can reach 96.5 g/L, and the transformation rate is greater than 97%. By adopting the method of the disclosure, the cost can be greatly reduced, and the industrialization process of production of ?-ketoisovaleric acid by an enzymatic transformation method is accelerated.Type: GrantFiled: June 18, 2021Date of Patent: October 10, 2023Assignee: Jiangnan UniversityInventors: Jing Wu, Shanshan Pei, Jia Liu, Wei Song, Xiulai Chen, Qiuling Luo
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Publication number: 20220235314Abstract: The invention provides a recombinant Escherichia coli strain for producing succinic acid and a construction method thereof. The by-product encoding genes in the E. coli strain FMME-N-2 are knocked out to obtain the E. coli strain FMME-N-5 (?focA-pflB-?ldhA-?pta-ackA); and the phosphoenolpyruvate carboxykinase pck derived from Actinobacillus succinogenes and the phosphite dehydrogenase ptxD derived from Pseudomonas stutzeri were overexpressed. The constructed plasmid pTrcHisA-pck-ptxD was introduced into the expression host E. coli FMME-N-5 (?focA-pflB-?ldhA-?pta-ackA), and the cells were screened in a plate containing ampicillin, to obtain an engineered strain E. coli FMME-N-5 (?focA-pflB-?ldhA-?pta-ackA)-pck-ptxD that can efficiently produce succinic acid. After fermentation by a two-stage fermentation strategy, the production of succinic acid reaches 137 g/L, the yield of succinic acid is up to 1 g/g glucose, and the space time yield is 1.Type: ApplicationFiled: November 12, 2020Publication date: July 28, 2022Inventors: Liming LIU, Wenxiu TANG, Chen SHEN, Qiuling LUO, Xiulai CHEN, Jia LIU, Cong GAO, Wei SONG
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Publication number: 20220204953Abstract: Disclosed is a mutant of acid phosphatase and an application thereof, belonging to the technical field of biological engineering. The disclosure provides a mutant of acid phosphatase PaAPaseMu3. By expressing the mutant of acid phosphatase PaAPaseMu3 in Escherichia coli and using a whole-cell conversion method, L-ascorbic acid is transformed into L-ascorbate-2-phosphate. Moreover, a catalytic system of the mutant of acid phosphatase PaAPaseMu3 is optimized from the aspects of reaction pH and temperature, so that a yield of L-ascorbate-2-phosphate can reach 90.1 g/L and a molar yield can reach 75.1%. Therefore, the problems of a high substrate cost, environmental pollution and the like before are greatly reduced, laying a foundation for the industrial green production of L-ascorbate-2-phosphate.Type: ApplicationFiled: March 15, 2022Publication date: June 30, 2022Inventors: Liming Liu, Xin Xu, Wei Song, Xiulai Chen, Jia Liu, Cong Gao, Jing Wu, Liang Guo
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Publication number: 20220002766Abstract: The disclosure discloses construction and application of an engineered strain of E. coli for producing malic acid by fixing CO2, and belongs to the field of fermentation. The engineered strain is obtained by performing genetic engineering transformation on Escherichia coli MG1655; the genetic engineering transformation includes knocking out a fumarate reductase gene, a fumarase gene, a lactate dehydrogenase gene and an alcohol dehydrogenase gene and freely overexpressing a formate dehydrogenase, an acetyl coenzyme A synthetase, an acylated acetaldehyde dehydrogenase, a formaldehyde lyase, a dihydroxyacetone kinase, a malic enzyme and a phosphite oxidoreductase to obtain a strain GH0407. The strain is used for producing malic acid by fermentation, anaerobic fermentation is performed for 72 hours with CO2 and glucose as a co-substrate, the production of malic acid reaches 39 g/L, the yield is 1.53 mol/mol, and accumulation of malic acid in the original strain is not achieved.Type: ApplicationFiled: September 20, 2021Publication date: January 6, 2022Inventors: Liming LIU, Guipeng HU, Xiulai CHEN, Danlei MA, Jia LIU, Qiuling LUO
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Publication number: 20210309974Abstract: The disclosure discloses preparation of an L-amino acid deaminase mutant and application thereof, belonging to the technical field of gene engineering. Through pmirLAAD protein modification, analysis of a flexible loop structure around a binding site of the pmirLAAD product, and design of the best mutant, the modification method of the disclosure overcomes the defect that the catalytic efficiency of the previous wild-type enzyme is reduced due to product inhibition, and is tested by experiments. Compared with the control, the catalytic efficiency (1.61 mM?·min?1) and the product inhibition constant (5.4 mM) of the finally obtained best mutant pmirLAADM4 are respectively increased by 5.2 times and 5.7 times. The yield of ?-ketoisovaleric acid can reach 96.5 g/L, and the transformation rate is greater than 97%. By adopting the method of the disclosure, the cost can be greatly reduced, and the industrialization process of production of ?-ketoisovaleric acid by an enzymatic transformation method is accelerated.Type: ApplicationFiled: June 18, 2021Publication date: October 7, 2021Inventors: Jing WU, Shanshan PEI, Jia LIU, Wei Song, Xiulai CHEN, Qiuling LUO
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Patent number: 10508279Abstract: The present invention relates to the field of biotechnology engineering. It provides a recombinant Escherichia coli that can produce fructosylated chondroitin with high yields and the method for constructing the recombinant strain. The present invention discloses a method for constructing an expression plasmid pETM6R1-RBS-glmM-GGGS-glmS that contains a glmM and a glmS gene under regulation of ribosome binding sites. The recombinant plasmid was transformed into E. coli K4 to obtain a recombinant E. coli strain ZQ33 that can produce fructosylated chondroitin up to 3.99 g·L?1 by fed-batch fermentation in a 5-L fermentor, which was increased by 108.90% compared to that of the wild type strain.Type: GrantFiled: February 8, 2018Date of Patent: December 17, 2019Assignee: Jiangnan UniversityInventors: Jing Wu, Quan Zhang, Liming Liu, Xiulai Chen, Jia Liu, Qiuling Luo
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Patent number: 10308919Abstract: The present invention provides a recombinant strain, construction method thereof and a method for producing acid phosphatase using the recombinant strain. In the invention, the phosphatase gene is obtained from Pseudomonas aeruginosa by a molecular biology method, the constructed expression plasmid is transformed into E. coli BL21 (DE3). The purified enzyme and whole cells were used for the conversion of ascorbic acid to ascorbic acid-2-phosphate. Ascorbic acid-2-phosphate can be efficiently produced by controlling the ratio of substrates. When the conversion reaction is performed at pH 4.5 under 40° C. for 8 h, the output of ascorbic acid-2-phosphate reaches 54.8 g/L, the conversion is 42.9% and the space time yield is 6.9 g/L/h.Type: GrantFiled: December 21, 2016Date of Patent: June 4, 2019Assignee: JIANGNAN UNIVERSITYInventors: Liming Liu, Wei Song, Jing Wu, Kai Zheng, Xiulai Chen
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Publication number: 20190032062Abstract: The present invention relates to the field of biotechnology engineering. It provides a recombinant Escherichia coli that can produce fructosylated chondroitin with high yields and the method for constructing the recombinant strain. The present invention discloses a method for constructing an expression plasmid pETM6R1-RBS-glmM-GGGS-glmS that contains a glmM and a glmS gene under regulation of ribosome binding sites. The recombinant plasmid was transformed into E. coli K4 to obtain a recombinant E. coli strain ZQ33 that can produce fructosylated chondroitin up to 3.99 g·L?1 by fed-batch fermentation in a 5-L fermentor, which was increased by 108.90% compared to that of the wild type strain.Type: ApplicationFiled: February 8, 2018Publication date: January 31, 2019Applicant: Jiangnan UniversityInventors: Jing Wu, Quan Zhang, Liming Liu, Xiulai Chen, Jia Liu, Qiuling Luo
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Publication number: 20180057802Abstract: The present invention provides a recombinant strain, construction method thereof and a method for producing acid phosphatase using the recombinant strain. In the invention, the phosphatase gene is obtained from Pseudomonas aeruginosa by a molecular biology method, the constructed expression plasmid is transformed into E. coli BL21 (DE3). The purified enzyme and whole cells were used for the conversion of ascorbic acid to ascorbic acid-2-phosphate. Ascorbic acid-2-phosphate can be efficiently produced by controlling the ratio of substrates. When the conversion reaction is performed at pH4.5 under 40° C. for 8 h, the output of ascorbic acid-2-phosphate reaches 54.8 ?/L, the conversion is 42.9% and the space time yield is 6.9 g/L/h.Type: ApplicationFiled: December 21, 2016Publication date: March 1, 2018Inventors: Liming LIU, Wei SONG, Jing WU, Kai ZHENG, Xiulai CHEN