Nantong Licheng Biological Engineering Co. Ltd

Tianjin University

Qinqing Gu

Baohong Hou

Junbo Gong

Qiuxiang Yin

Jingkang Wang

Jiangbo Li

Shichao Du

Kaifei Zhao

Yi Sun

Feng Jin

Xiaohua Wu

Hongzhi Xia

Jian Chen

Long Liu

Haiyan Xi

Xueqin Lv

Jianghua Li

Guocheng Du

Shixiu Cui

Shiping Tang

Xin Pan

Zhongshi Liu

The present disclosure provides a recombinantfor increasing the yield of menaquinone 7 (MK-7) and application thereof, and belongs to the field of genetic engineering. In the present disclosure, 14 recombinant strains BS1-BS14 are constructed through the modification of genes related to the biosynthetic pathway of MK-7 on a chromosome of, wherein BS6-BS14 significantly increase the yield of the MK-7, reaching up to 33.5 mg/L, which is 3.53 times the yield of the original strain of wild-type168. The present disclosure further provides a method for modifying the MK-7 biosynthetic pathway in microorganisms to increase the yield of the MK-7, providing a theoretical basis for constructing a high-yielding strain of the MK-7.

Recombinantfor increasing yield of menaquinone 7 and application thereof

A method for preparing a new crystalline form of &#x3b3;-aminobutyric acid, including the steps of: S1: preparing a &#x3b3;-aminobutyric acid solution at an initial concentration of 0.5-1.0 g/mL by adding crude &#x3b3;-aminobutyric acid to water; adding an additive to the &#x3b3;-aminobutyric acid solution, raising the temperature to 50-80&#xb0; C., stirring to produce a clear solution; and S2: obtaining a suspension by evaporating water from the product of S1 under reduced pressure and at 50-80&#xb0; C.; obtaining a wet product by filtering the suspension; drying the wet product to obtain the new crystalline form of &#x3b3;-aminobutyric acid. The preparation method of the new crystalline form of &#x3b3;-aminobutyric acid is simple, easy to operate, low in energy consumption, economical and environmentally friendly. It is suitable for large-scale industrial production.

Crystalline form of gamma-aminobutyric acid and preparation method thereof

The present invention discloses a &#x3b3;-aminobutyric acid hemihydrate crystal, its molecular formula is CHNO.0.5HO. It also discloses a method of preparing a &#x3b3;-aminobutyric acid hemihydrate crystal, including first adding crude &#x3b3;-aminobutyric acid to water to prepare a &#x3b3;-aminobutyric acid suspension at an initial concentration of 1.2-2.0 g/mL; then stirring the suspension at a constant temperature of 5-10&#xb0; C. for 6-12 hours, followed by filtering and drying to obtain the &#x3b3;-aminobutyric acid hemihydrate crystal. The &#x3b3;-aminobutyric acid hemihydrate crystal is stable, does not easily absorb moisture and agglomerate, and is convenient for further processing and use. The crystal has a large main particle size, uniform particle size distribution, high bulk density, good flowability, and a purity of &#x2265;99%. The preparation method of the crystal according to the present invention is simple, easy to operate, highly efficient and low in energy consumption, and is suitable for large-scale industrial production.

Gamma-aminobutyric acid hemihydrate crystal and preparation method thereof

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Jiangsu, China

Qinqing Gu