Abstract: A method for producing 2-keto-3-deoxygluconate (KDG) from 2-(acetylamino)-2-deoxy-D-gluconic acid (GlcNAc1A) by two enzymes; GlcNAc1A is converted to KDG by incubating GlcNAc1A with a deacetylase OngB at 25° C. for 4-12 h and then with a deaminase OngC at 25° C. for another 10-15 h; it constructs two engineered E. coli/pET22b-ongB (carrying the ongB gene) and E. coli/pET22b-ongC (carrying the ongC gene) strains to prepare recombinant proteins OngB and OngC, respectively; at the action of these two enzymes, OngB and OngC, GlcNAc1A is converted to KDG, which solves the bottleneck of GlcNAc1A utilization during the bioconversion of chitin; the KDG is an important metabolic intermediate to synthesize furan derivatives, herbicides, food additives and other industrially important chemical compounds, having wide industrial applications.

Abstract: MLX1034 is from Polaribacter sp. Q13, and has the amino acid sequence of the 1,3/1,4-xylanase MLX1034 is listed in SEQ ID NO.1; a nucleotide sequence of the gene is listed in SEQ ID NO.2; the 1,3/1,4-xylanase MLX1034 in the invention is capable of efficiently and specifically degrading 1,3/1,4-xylan and producing xylooligosaccharides with DP values above one; in addition, the physical and chemical properties of the 1,3/1,4-xylanase MLX1034 are stable enough to hydrolyze 1,3/1,4-xylan at room temperature; the 1,3/1,4-xylanase MLX1034 is suitable for the industrial production of red algal xylooligosaccharides at low energy costs.

Abstract: A method for producing 2-keto-3-deoxygluconate (KDG) from 2-(acetylamino)-2-deoxy-D-gluconic acid (GlcNAc1A) by two enzymes; GlcNAc1A is converted to KDG by incubating GlcNAc1A with a deacetylase OngB at 25° C. for 4-12 h and then with a deaminase OngC at 25° C. for another 10-15 h; it constructs two engineered E. coli/pET22b-ongB (carrying the ongB gene) and E. coli/pET22b-ongC (carrying the ongC gene) strains to prepare recombinant proteins OngB and OngC, respectively; at the action of these two enzymes, OngB and OngC, GlcNAc1A is converted to KDG, which solves the bottleneck of GlcNAc1A utilization during the bioconversion of chitin; the KDG is an important metabolic intermediate to synthesize furan derivatives, herbicides, food additives and other industrially important chemical compounds, having wide industrial applications.

Abstract: It relates to a method for preparation of four kinds of 2?, 3?-cNMPs (2?, 3?-cAMP, 2?, 3?-cGMP, 2?, 3?-cCMP and 2?, 3?-cUMP), comprising steps of: (1) extract genomic DNA and amplify gene If3; (2) ligate If3 gene to expression plasmid to construct a recombinant vector, and transfer the recombinant vector to E. coli to obtain a recombinant strain. Cultivate the recombinant strain and collect the fermentation broth; (3) collect the cells form the fermentation broth and disrupt the cells, and then purify the recombinant protein IF3 from the cell extract by Ni2+-nitrilotriacetic acid resin. Incubate the recombinant protein IF3 solution at 0° C. for 3 days to release 2?, 3?-cNMPs from IF3, and centrifuge the solution; (4) Ultrafiltrate the supernatant to remove proteins, and prepare four kinds of 2?, 3?-cNMPs by high-performance liquid chromatographic (HPLC) on a C18 reversed-phase column.

Abstract: It relates to a LfliZ gene and its application. The sequence of gene LfliZ is shown in SEQ ID NO.1. This invention also relates to the recombinant protein LfliZ encoded by LfliZ gene and its application in preparation of 2?, 3?-cNMPs. The recombinant LfliZ protein encoded by gene LfliZ can bind four kinds of 2?, 3?-cNMPs during its expression in Escherichia coli. Four kinds of 2?, 3?-cNMPs can be prepared simultaneously from the recombinant E. coli by extracting the recombinant protein LfliZ. The yield of 2?, 3?-cNMPs reaches 2.5 mg/L fermentation broth by the method in the present invention, indicating that this method has a good application potential.

Abstract: It relates to a LfliZ gene and its application. The sequence of gene LfliZ is shown in SEQ ID NO.1. This invention also relates to the recombinant protein LfliZ encoded by LfliZ gene and its application in preparation of 2?,3?-cNMPs. The recombinant LfliZ protein encoded by gene LfliZ can bind four kinds of 2?,3?-cNMPs during its expression in Escherichia coli. Four kinds of 2?,3?-cNMPs can be prepared simultaneously from the recombinant E. coli by extracting the recombinant protein LfliZ. The yield of 2?,3?-cNMPs reaches 2.5 mg/L fermentation broth by the method in the present invention, indicating that this method has a good application potential.

Abstract: It relates to a method for preparation of four kinds of 2?, 3?-cNMPs (2?, 3?-cAMP, 2?, 3?-cGMP, 2?, 3?-cCMP and 2?, 3?-cUMP), comprising steps of: (1) extract genomic DNA and amplify gene If3; (2) ligate If3 gene to expression plasmid to construct a recombinant vector, and transfer the recombinant vector to E. coli to obtain a recombinant strain. Cultivate the recombinant strain and collect the fermentation broth; (3) collect the cells form the fermentation broth and disrupt the cells, and then purify the recombinant protein IF3 from the cell extract by Ni2+-nitrilotriacetic acid resin. Incubate the recombinant protein IF3 solution at 0° C. for 3 days to release 2?, 3?-cNMPs from IF3, and centrifuge the solution; (4) Ultrafiltrate the supernatant to remove proteins, and prepare four kinds of 2?, 3?-cNMPs by high-performance liquid chromatographic (HPLC) on a C18 reversed-phase column.