Abstract: A catalyst for continuous production of 1,1,1,3-tetrachloropropane through gas-solid reaction as well as a preparation method and use thereof are provided. The catalyst includes a zero-valent iron and phosphorus co-modified carbon material which includes a carbon material as a carrier, a zero-valent iron supported onto the carrier and serving as an active component, and a phosphate functional group formed on the surface of the carbon material. The preparation method includes: co-modifying a carbon material using a ferric salt and organic phosphorus to obtain the catalyst for continuous production of 1,1,1,3-tetrachloropropane through gas-solid reaction. The present application further provides a method for continuous production of 1,1,1,3-tetrachloropropane through gas-solid reaction.

Abstract: Provided are mutants PHY1, PHY4 and PHY5 of a wild-type phytase APPA. After being treated for 10 min at 80° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 33.85%, 53.11% and 75.86% compared with that of APPA-M; after being treated for 5 min at 85° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 14.89%, 28.45% and 44.94% compared with that of APPA-M, and the heat resistance of these mutants is significantly higher than that of APPA-M.

Abstract: Provided are a phytase mutant and a coding DNA molecule thereof, a vector, and a host cell. The phytase mutant comprises an amino acid sequence having at least 90% identity with SEQ ID NO: 3, and compared with SEQ ID NO: 3, and contains an amino acid substitution at at least one position selected from the group consisting of 36, 126, 211, 253, 258, and 266. The heat resistance of the mutant is significantly improved, thus facilitating the wide application of phytase in feed.

Abstract: Provided is a xylanase mutant having improved specific activity, comprising any one or more mutation sites of M78F, V1431, R148K, F163W, I177V, and V206L. The specific activity of the mutant is improved, the production cost of xylanase is reduced, and the mutant can be used in feed.

Abstract: The present invention relates to the technical field of biology, in particular to a phytase mutant, a preparation method therefor and an application thereof, a DNA molecule encoding the phytase mutant, a vector, and a host cell. The mutant provided by the present invention contains the substituent of an amino acid at at least one position selected from the following group: 36, 69, 89, 91, 111, 202, 213, 225, 238, 243, 253, 258, and 266. The heat resistance of the mutant is significantly improved, thereby facilitating the wide application of the phytase in feed.

Abstract: Provided are mutants PHY1, PHY4 and PHY5 of a wild-type phytase APPA. After being treated for 10 min at 80° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 33.85%, 53.11% and 75.86% compared with that of APPA-M; after being treated for 5 min at 85° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 14.89%, 28.45% and 44.94% compared with that of APPA-M, and the heat resistance of these mutants is significantly higher than that of APPA-M.

Abstract: Provided are phytase mutants, preparation methods therefor and uses thereof, DNA molecule encoding each of the phytase mutants, a vector comprising the DNA molecule, and a host cell comprising the vector.

Abstract: Provided are mutants PHY1, PHY4 and PHY5 of a wild-type phytase APPA. After being treated for 10 min at 80° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 33.85%, 53.11% and 75.86% compared with that of APPA-M; after being treated for 5 min at 85° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 14.89%, 28.45% and 44.94% compared with that of APPA-M, and the heat resistance of these mutants is significantly higher than that of APPA-M.

Abstract: The present invention relates to the technical field of protein engineering, and, in particular, to a xylanase mutant with improved heat tolerance. The present invention artificially introduces two or three unnatural disulfide bridges into xylanase by site-directed mutagenesis and obtains the mutants XynA1 and XynA2 with improved heat tolerance, especially the mutant XynA2 into which three disulfide bridges are introduced, achieving residual enzyme activity of 75% after treatment at 80° C. for 5 min, 72% higher than the residual enzyme activity of the mutant XynA1. The present invention further obtains, by screening, three mutation sites Q51N, H143K, and Q161F that can significantly increase the heat tolerance of mutants, and introduction of the mutation sites into the XynA1 and XynA2 xylanases, whether at a single point or a combination of two points or a combination of three points, can effectively improve the heat tolerance of the mutants.

Abstract: Provided are mutants PHY1, PHY4 and PHY5 of a wild-type phytase APPA. After being treated for 10 min at 80° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 33.85%, 53.11% and 75.86% compared with that of APPA-M; after being treated for 5 min at 85° C., the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively higher by 14.89%, 28.45% and 44.94% compared with that of APPA-M, and the heat resistance of these mutants is significantly higher than that of APPA-M.

Abstract: Provided are phytase mutants, preparation methods therefor and uses thereof, DNA molecule encoding each of the phytase mutants, a vector comprising the DNA molecule, and a host cell comprising the vector.

Abstract: The present invention relates to the technical field of protein engineering, and, in particular, to a xylanase mutant with improved heat tolerance. The present invention artificially introduces two or three unnatural disulfide bridges into xylanase by site-directed mutagenesis and obtains the mutants XynA1 and XynA2 with improved heat tolerance, especially the mutant XynA2 into which three disulfide bridges are introduced, achieving residual enzyme activity of 75% after treatment at 80° C. for 5 min, 72% higher than the residual enzyme activity of the mutant XynA1. The present invention further obtains, by screening, three mutation sites Q51N, H143K, and Q161F that can significantly increase the heat tolerance of mutants, and introduction of the mutation sites into the XynA1 and XynA2 xylanases, whether at a single point or a combination of two points or a combination of three points, can effectively improve the heat tolerance of the mutants.