Use of a stereoselective transaminase in the asymmetric synthesis of a chiral amine. In particular, provided is use of a polypeptide in the production of a chiral amine or a downstream product using a chiral amine as a precursor. Further provided is a method for producing a chiral amine, comprising culturing a strain expressing the polypeptide so as to obtain a chiral amine. Further provided are novel prochiral compounds, a chiral amine production strain and a method for constructing the chiral amine production strain. The stereoselective transaminase has a broad substrate spectrum and thus has a broad application potential in the preparation of a chiral amine.

Provided are transaminase mutants and uses thereof. The transaminase mutant is obtained by one or more amino acid mutations occurring in SEQ ID NO: 2 or is a mutant with a conserved amino acid mutation obtained by taking the sequence SEQ ID NO: 1 of a wild-type CvTA transaminase as a reference. Compared with wild-type transaminases, the catalytic activity of the mutant is improved to different degrees, so that the production efficiency of chiral amine compound synthesis may be improved.

Provided are transaminase mutants and uses thereof. The transaminase mutant is obtained by one or more amino acid mutations occurring in SEQ ID NO: 2 or is a mutant with a conserved amino acid mutation obtained by taking the sequence SEQ ID NO: 1 of a wild-type CvTA transaminase as a reference. Compared with wild-type transaminases, the catalytic activity of the mutant is improved to different degrees, so that the production efficiency of chiral amine compound synthesis may be improved.

Provided is a method for synthesizing a chiral amine compound. A transaminase is used to transaminate a ketone substrate under the action of an amino donor, to obtain the chiral amine compound; and the conserved amino acid sequence region of the transaminase at least includes a region 1 (MAGLWCVN) and a region 2 (YNTFFKT). With the transaminase with the specific conserved amino acid sequence region to synthesize a large sterically hindered chiral amine, the enzyme catalytic reaction volume is small, the synthesizing route is short, the product yield is high, a high-cost noble metal is not required for catalysis under the synthesizing conditions, three wastes are reduced, and the production cost is saved.

Provided is a method for synthesizing a chiral amine compound. A transaminase is used to transaminate a ketone substrate under the action of an amino donor, to obtain the chiral amine compound; and the conserved amino acid sequence region of the transaminase at least includes a region 1 (MAGLWCVN) and a region 2 (YNTFFKT). With the transaminase with the specific conserved amino acid sequence region to synthesize a large sterically hindered chiral amine, the enzyme catalytic reaction volume is small, the synthesizing route is short, the product yield is high, a high-cost noble metal is not required for catalysis under the synthesizing conditions, three wastes are reduced, and the production cost is saved.

A species of Burkholderia sp with no known pathogenicity to vertebrates but with pesticidal activity (e.g., plants, insects, fungi, weeds and nematodes) is provided. Also provided are natural products derived from a culture of said species and methods of controlling pests using said natural products.

A species of Burkholderia sp with no known pathogenicity to vertebrates but with pesticidal activity (e.g., plants, insects, fungi, weeds and nematodes) is provided. Also provided are natural products derived from a culture of said species and methods of controlling pests using said natural products.

Described are techniques in video coding and/or decoding that allow for selectively breaking prediction and/or in loop filtering across segment boundaries between different segments of a video picture. A high layer syntax element, such as a parameter set or a slice header, may contain one or more indications signalling to an encoder and/or decoder whether an associated prediction or loop filtering tool may be applied across the segment boundary. In response to such one or more indications, the encoder and/or decoder may then control the prediction or loop filtering tool accordingly.

Described are techniques in video coding and/or decoding that allow for selectively breaking prediction and/or in loop filtering across segment boundaries between different segments of a video picture. A high layer syntax element, such as a parameter set or a slice header, may contain one or more indications signalling to an encoder and/or decoder whether an associated prediction or loop filtering tool may be applied across the segment boundary. In response to such one or more indications, the encoder and/or decoder may then control the prediction or loop filtering tool accordingly.

Described is picture segmentation through columns and slices in video encoding and decoding. A video picture is divided into a plurality of columns, each column covering only a part of the video picture in a horizontal dimension. All coded tree blocks (CTBs) belonging to a slice may belong to one or more columns. The columns may be used to break the same or different prediction or in-loop filtering mechanisms of the video coding, and the CTB scan order used for encoding and/or decoding may be local to a column. Column widths may be indicated in a parameter set and/or may be adjusted at the slice level. At the decoder, column width may be parsed from the bitstream, and slice decoding may occur in one or more columns.