Jiangnan University

Tongfu Microelectronics Co., Ltd.

Jing Wu

Lingqia Su

Xiulai Chen

Wei Song

Liming Liu

Jia Liu

Dan Wu

Jian Chen

Qiuling Luo

Yan Huang

Kailin Yao

Xin Gao

Chun Lan Chen

Lei Wang

Li Wang

Yun Fang

Haijun Wang

Yongmei Xia

Jun Liu

Honghui Wang

Cong Gao

Xiang Liu

Liang Guo

Xueyi Hu

Fei Xu

Ye Fan

Lengtao Gu

Jinyun Feng

Sheng Chen

Shanshan Pei

Quan Zhang

Xin Xu

Wei Xia

Xinghao Xu

Zhuoyu Zhou

Zhendong Wang

Xiumei Tao

Kai Zheng

Yusheng Wang

Ruoyu Hong

Haizhong Shi

Junchen Dong

Li Du

Zirui Wang

Zhengfei Yan

Disclosed is an acid phosphatase mutant obtained fromhaving the amino acid sequence of SEQ ID NO:3 and method of using the mutant in the technical field of biological engineering. The disclosure provides a mutant of acid phosphatase PaAPase. By expressing the mutant of acid phosphatase PaAPaseinand using a whole-cell conversion method, L-ascorbic acid is transformed into L-ascorbate-2-phosphate. Moreover, the problems of a high substrate cost, environmental pollution and the like are greatly reduced, laying a foundation for the industrial green production of L-ascorbate-2-phosphate.

Acid phosphatase mutants and methods of using the same

The disclosure discloses the preparation of thermophilic β-glucosidase and the application thereof, which belongs to the technical field of genetic engineering and fermentation engineering. The present disclosure heterologously expresses the β-glucosidase TpBgl3A derived from thermophilic fungusby constructing a recombinant bacteria. The enzyme production of recombinant bacteria can reach 2324 U/mL in a 3.6 L fermenter. The resulting β-glucosidase TpBgl3A can produce gentioligosaccharides with a high conversion rate using glucose as a substrate at a lower enzyme amount added, which significantly reduces production costs. In the reaction system using glucose and cellobiose as substrates, the conversion rate of gentioligosaccharide reaches 26.2%, which has the potential for industrial production of gentioligosaccharide.

Preparation of thermophilic beta-glucosidase and application thereof

The disclosure discloses a method to elevate the amount of steviol glycosides remained in the recrystallization mother liquor ofextract, and belongs to the field of modification and extraction of natural compounds. The disclosure adopts lactase for highly specific catalytic hydrolysis of stevioside to convert stevioside into rubusoside which usually can only be obtained from leaves ofS. Lee; and meanwhile, after stevioside in the mother liquor glycosides is converted, since the polarity difference between rubusoside and rebaudioside A is far larger than the polarity difference between stevioside and rebaudioside A, rebaudioside A is more easily separated out of the mother liquor glycosides. A technology provided by the disclosure is also applicable to value increment of mixed steviol glycosides containing stevioside and is beneficial for separating out rebaudioside A from the mixed steviol glycosides.

Method to elevate the amount of steviol glycosides remained in the recrystallization mother liquor of Stevia extract

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&#xb7;min) and the product inhibition constant (5.4 mM) of the finally obtained best mutant pmirLAADare respectively increased by 5.2 times and 5.7 times. The yield of &#x3b1;-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 &#x3b1;-ketoisovaleric acid by an enzymatic transformation method is accelerated.

Preparation of L-amino acid deaminase mutant and application thereof

Disclosed is a method for promoting extracellular expression of proteins inusing cutinase, which belongs to the technical fields of genetic engineering, enzyme engineering and microbial engineering. It teaches co-expressing a cutinase mutant and a target protein into promote extracellular expression of the target protein which is naturally located inside cells. The target protein includes xylose isomerase, 4,6-&#x3b1;-glucosyltransferase, 4-&#x3b1;-glucosyltransferase, trehalose synthase, branching enzyme and the like. The invention can achieve extracellular expression of intracellularly localized target protein, improve the production efficiency, reduce the production cost and simplify the subsequent extraction process.

Methods for promoting extracellular expression of proteins inusing a cutinase

The present disclosure disclosescapable of degrading polyethylene terephthalate and an intermediate thereof, and belongs to the technical field of microorganisms. The present disclosure providesJWG-G2 capable of degrading the polyethylene terephthalate. AfterJWG-G2 is inoculated into an inorganic salt liquid medium containing 2 g/L polyethylene terephthalate plastic particles with an inoculation quantity of 1&#xd7;10CFU/mL to be cultivated for 5 d, the polyethylene terephthalate plastic particles can be partially degraded into monohydroxyethyl terephthalate and terephthalic acid capable of being directly recycled, ester bond functional groups on surfaces of the polyethylene terephthalate plastic particles can be reduced, and a weight loss ratio of the polyethylene terephthalate plastic particles can reach 5.6%. Therefore,JWG-G2 of the present disclosure has an extremely high application prospect in degradation of the polyethylene terephthalate.

capable of degrading polyethylene terephthalate and intermediate thereof

The present invention discloses a mutant of cyclodextrin glycosyltransferase and belongs to the fields of gene engineering and enzyme engineering. According to the present invention, a mutant having higher disproportionation activity of cyclodextrin glycosyltransferase is obtained by mutating the cyclodextrin glycosyltransferase. The disproportionation activity of enzymes of mutants V6D, S90G, T168A, T171A, T383A, G608A, and V6D/S90G/T168A/T171A/T383A/G608A, is respectively 1.89 times, 1.21 times, 1.21 times, 1.22 times, 1.32 times, 2.03 times, and 3.16 times that of the wild type enzyme in shake flask fermentations.

Mutant of cyclodextrin glycosyltransferase

The present invention discloses a &#x3b2;-galactosidase mutant, and a preparation method and application thereof, belonging to the fields of gene engineering and enzyme engineering. Amino acids of specific sites in the &#x3b2;-galactosidase are mutated, the &#x3b2;-galactosidase is transferred into a recombinant bacterium, and enzymatic transformation is performed under optimized conditions, so that the yield of galactooligosaccharide produced by the mutant reaches 59.8%, which is increased by about 70% as compared with that of wild enzyme, thereby implementing the increase of the galactooligosaccharide yield. The present invention has very high industrialized application value.

Beta-galactosidase mutant, and preparation method and application thereof

Disclosed is a method for preparing a resistant dextrin product by using compound enzyme treatment. Starch is first subjected to high-temperature acidolysis to obtain pyrodextrin which is used as the substrate for the enzyme treatment. A compound enzyme reaction system including a starch branching enzyme and a CGTase is used for preparing the resistant dextrin product. The starch branching enzyme and the CGTase are added simultaneously or sequentially to treat the pyrodextrin to further increase the content of the resistant component in the product. The content of the resistant component of the enzyme treated product reaches up to 65.3%, a 21.3% increase from that of the pyrodextrin before the enzyme treatment.

Method for preparing resistant dextrin by using a starch branching enzyme and a cyclodextrin glycosyltransferase

The present invention relates to preparation and application of a cyclodextrin glucosyltransferase mutant, belonging to the fields of gene engineering and enzyme engineering. By mutating amino acids of cyclodextrin glucosyltransferase, the enzyme activity of the obtained mutant can reach 2.5 times that of wild enzyme. In addition, the cyclodextrin glucosyltransferase mutant obtained in the present invention is simple in purification and suitable for industrial production.

Preparation and application of cyclodextrin glucosyltransferase mutant

The present disclosure discloses a maltooligosyl trehalose synthase mutant with improved thermal stability, and belongs to the technical fields of enzyme engineering and protein engineering. The residual enzyme activities of the MTSase mutants S361R, S444E, S361R/S444E, S361K/S444E, G415P/S361R/S444E and G415P consistent with the present disclosure after treatment at 60&#xb0; C. for 10 min are respectively 70.3%, 50.1%, 83.5%, 65.9%, 100% and 80.7%, which are respectively 1.6, 1.1, 1.9, 1.5, 2.3 and 1.9 times of that of the wild type. The half-lives of the S361R/S444E and G415P/S361R/S444E at 60&#xb0; C. are respectively 14.9 min and 90.8 min which are respectively 3.2 and 19.7 times of that of the wild type, indicating that the thermal stability of the MTSase mutant consistent with the present disclosure is significantly improved than that of the wild type.

Maltooligosyl trehalose synthase mutant with improved thermal stability

&#x3b2;-galactosidase mutant, and preparation method and application thereof

Disclosed are Dpo4 DNA polymerase mutants with increased DNA synthesis processivity. The mutant enzymes, Dpo4 A181D and Dpo4 E63K, are constructed based on the wild-type Dpo4 derived fromto obtain Dpo4DNA polymerase mutants with increased DNA processivity. The extension length of Dpo4 A181D and Dpo4 E63K are respectively increased by 25% and 18.8% than that of the wild-type Dpo4. The fidelity of Dpo4 A181D and wild-type Dpo4 are similar, and the fidelity of Dpo4 E63K is increased from that of the wild-type Dpo4. In summary, the mutants Dpo4 A181D and Dpo4 E63K obtained by the present invention have increased processivity compared to that of the wild-type Dpo4 DNA polymerase.

DNA polymerase mutants with increased processivity of DNA synthesis

The present invention relates to the field of biotechnology engineering. It provides a recombinantthat 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 intoK4 to obtain a recombinantstrain ZQ33 that can produce fructosylated chondroitin up to 3.99 g&#xb7;Lby fed-batch fermentation in a 5-L fermentor, which was increased by 108.90% compared to that of the wild type strain.

Recombinantfor high efficiency production of fructosylated chondroitin and method for making thereof

The present invention discloses a maltooligosyl trehalose trehalohydrolase (MTHase) mutant and application thereof, belonging to the technical fields of gene engineering and enzyme engineering. The present invention provides a series of MTHase mutants to prepare trehalose, having a better effect. Further, the MTHase mutant is expressed inBL21 (DE3) and the enzyme is optimized by fermentation, which can significantly increase the yield of enzymes.

Maltooligosyl trehalose trehalohydrolase (MTHase) mutant and application thereof

Growing community of inventors

Wuxi, China

Jing Wu