Jiangnan University

Roquette Freres

Bo Jiang

Tao Zhang

Ming Miao

Wanmeng Mu

Hangyu Jiang

Zhengyu Jin

Pierre Lanos

Liuming Zhou

Yao Liu

Yang Qi

Chen Chen

Min Jia

Wenli Zhang

Yingying Zhu

Mengli Li

Mengying Hu

Yuqi Yang

Jingjing Chen

Xiaoli Duan

Qing Meng

Xiaolin Yao

Luhua Zheng

Shuhuai Yu

The disclosure discloses a feruloyl esterase and application thereof, and belongs to the technical field of microorganisms. The disclosure provides a feruloyl esterase with an amino acid sequence shown in SEQ ID NO: 2 and specific enzyme activity as high as 519 U/g. The disclosure provides a recombinantwhich usesas a host, expresses a gene encoding the feruloyl esterase with an amino acid sequence shown in SEQ ID NO: 2, and can be used for producing the feruloyl esterase with a high yield. The process specifically includes inoculating a fermentation culture medium with the recombinantfor fermentation for 14 hours, and the enzyme activity of the feruloyl esterase in a cell disruption supernatant can be as high as 82.53 U/mL.

Feruloyl esterase and application thereof

The disclosure discloses a method for producing maltodextrin with a single polymerization degree by multienzyme coupling, and belongs to the technical field of biology. The disclosure provides a method for producing non-reducing maltodextrin with a uniform and low polymerization degree. After a reaction is preformed for 2-6 hours by using the method of the disclosure, the content of 4-O-α-maltohexaosyl α-D-glucoside in a reaction solution can be as high as 57.2% to 77.3%, accounting for 50% to 90% of the total amount of maltodextrin in the reaction solution. In maltodextrin prepared by using the method of the disclosure, non-reducing maltodextrin with low polymerization degree only includes 4-O-α-maltohexaosyl α-D-glucoside, and the content of non-reducing maltodextrin with low polymerization degree can be 50% to 90% of the total amount of maltodextrin. Therefore, only filtration is needed in preparation of non-reducing maltodextrin with low polymerization degree by using the method of the disclosure; additional separation and purification steps are not needed; high-purity non-reducing maltodextrin with low polymerization degree can be obtained; and the production cost is low.

Method for producing maltodextrin with single polymerization degree by multienzyme coupling

The disclosure discloses an alginate lyase and application thereof, and belongs to the technical field of biology. The alginate lyase provided by the disclosure has high degradation activity, and the enzyme activity reaches 65 U/mg; the alginate lyase is stable in nature, and the enzyme activity remains 98% or higher of the initial enzyme activity after storage at 4° C. for 18 months; and the alginate lyase has high product specificity. The disclosure usesas a host to express the alginate lyase derived from, the obtained recombinantcan produce the alginate lyase secreted extracellularly in a conventional LB medium without adding an induction substrate sodium alginate, so the downstream processing technology of protein is simplified, and the disclosure has great industrial application potential.

Alginate lyase and application thereof

The present disclosure discloses a strain producing D-allulose 3-epimerase and application thereof, and belongs to the technical field of bioengineering. The present disclosure provides a method for improving the expression of D-allulose 3-epimerase by screening promoters and optimizing RBS thereof. The recombinantconstructed using thevectors pP43NMK-hag and pP43NMK-hag-RBS4 provided by the present disclosure improves the enzyme activity of a target gene D-allulose 3-epimerase, and theenzyme activities in shake flasks upon transformation are 1.30 times and 1.69 times that of an original vector. The present disclosure further provides a non-antibiotic resistance vector and a non-antibiotic resistance recombinantstrain. Using the non-antibiotic resistance strain1A751-dal-/pP43NMK-hag-RBS4-dpe-dal provided by the present disclosure, the highest fermentation enzyme activity in a shake flask is 24.72 U/mL, and the enzyme activity in a fermenter is 714.8 U/mL.

Strain producing D-allulose 3-epimerase and application thereof

The present disclosure discloses an amylopectin-based cyclic glucan and the processing method for the same, and belongs to the technical field of food processing. The present disclosure uses a starch as a raw material, prepares an amylopectin-based cyclic glucan through sugar chain degradation grading and glycosidase-catalyzed trans-glycoside technology, and can be used as a steady-state carrier material for food active factors. The method of the disclosure has advantages of green environmental protection, high processing yield and low cost. The prepared product has high branching degree, special large ring structure and good water solubility, and can be used for steady-state delivery and active protection of natural functional substances, involving nutritional food, medicine, daily chemicals and other fields.

Amylopectin-based cyclic glucan and method for processing the same

The present disclosure discloses a processing method for intelligent hydrogel from nano-scale starch particles, and belongs to the technical field of nutritional health food. The present disclosure uses dendritic water-soluble starch particles as a skeleton and utilizes a transglycosidation and chain extension-glycan entanglement reaction of glycosyltransferase to obtain an intelligent hydrogel having a spatial reticular structure. The product provided by the present disclosure is an intelligent starch-based hydrogel which has good rehydration capability, biocompatibility, strong gel strength, enzymatic response irreversibility, pH response reversibility, can carry multiple nutritional factors. The hydrogel provided by the present disclosure can protect and control the release of food functional factors, and can be applied to food, biological drug loading, functional materials and the like.

Processing method for intelligent hydrogel from nanometer starch particles

The present invention discloses a glucan-based shell-core structure carrier material and preparation and application thereof, and belongs to the technical field of modern food processing. Spherical hyperbranched water-soluble amylum grains are used as the raw material, and an enzymatic grafting and chain extending process is adopted for treatment to modify the surfaces of water-soluble glucan molecules into a firm shell structure with densely cumulated crystal structures, and form the glucan-based carrying material with the shell-core structure of which an inner core cavity has an amorphous state and an outer shell layer has a crystalline state. The adopted spherical hyperbranched water-soluble amylum grains have wide sources of raw materials and are not limited by producing areas and seasons; the preparation has simple and convenient steps, easy operation, controllable reaction conditions, relatively low cost and basically no pollution to the environment; and the prepared product can effectively protect, deliver and release functional nutritional components, can be applied to multiple fields of food, medicine, chemicals for daily use and the like, and has great market prospects and broad economic benefits.

Preparation of glucan-based shell-core structure carrier material and its application thereof

A genetically engineered arginine deiminase reconstructed by site-directed mutagenesis belongs to the technical field of genetic engineering technology. Its amino acid sequence is shown as SEQ ID No. 1. In the amino acid sequence of the arginine deiminase reconstructed by site-directed mutagenesis, glycine at position 264 is mutated to proline, compared to an amino acid sequence of native arginine deiminase. Compared with wild type enzyme, the effective pH range effect of the mutated arginine deiminase according to the present invention is broadened to a certain extent, and especially a good enzyme activity is achieved at physiological pH 7.4. With the broadening of the effective pH effect range, the mutant enzyme still has higher stability under the condition of pH 5.5-7.5. Therefore, the problem that the arginine deiminase generally is low in enzymatic activity and short in half-life in vivo under physiological conditions in clinical application for tumor therapy is solved, and a good condition for using the enzyme and an encoding gene thereof for clinical treatment is created.

Genetically engineered arginine deiminase modified by site-directed mutagenesis

An arginine deiminase mutant with improved enzyme activity and temperature stability and application thereof were provided, belonging to the technical field of genetic engineering and enzyme engineering. The arginine deiminase mutant is proline, namely Gly292 Pro, mutated from glycine near an enzyme active center. A wild-type arginine deiminase arcA coding gene is molecularly modified by a site-directed mutation technique to obtain a mutant enzyme ADIG292P, which has glycine at position 292 of an amino acid sequence of the wild type arginine deiminase mutated to proline. The arginine deiminase, modified by site-directed mutation, of the present invention has 1.5 times of increase in enzyme activity and 5.43 times of increase in half-life period at 40&#xb0; C. compared with the wild-type enzyme, which solves the problems of low catalytic ability and temperature stability during the catalytic synthesis of citrulline using arginine deiminase, and lays a foundation for industrial production of efficient synthesis of citrulline and medication application.

Arginine deiminase mutant methods of using the same

The present invention relates to an improved variant of a D-psicose 3-epimerase and its uses.

Variant of D-psicose 3-epimerase and uses thereof

Arginine deiminase mutant and methods of using the same

The invention discloses a high-efficiency synthesis method of difructose anhydride III. The method comprises the following steps: firstly converting sucrose into inulin by using inulosucrase without separating polysaccharide, and then converting inulin by using inulin fructotransferase to synthesize the functional disaccharide difructose anhydride III. The method has the advantages of simple process and high efficiency, and a conversion rate of synthesizing inulin into difructose anhydride III can reach 40%-54%. In order to obtain purer difructose anhydride III, yeast is utilized to remove small molecule monosaccharides in a reaction solution, and the finally obtained purer difructose anhydride III can be easily separated and purified. Thus, the method has broad market application prospects.

Growing community of inventors

Wuxi, China

Bo Jiang