Nantong Licheng Biological Engineering Co. Ltd

Tianjin University

Jiangbo Li

Qinqing Gu

Yi Sun

Hongzhi Xia

Baohong Hou

Junbo Gong

Qiuxiang Yin

Jingkang Wang

Shichao Du

Feng Jin

Kaifei Zhao

Xueqin Lv

Long Liu

Jianghua Li

Guocheng Du

Bo Tang

Shixiu Cui

Xin Pan

Yulei Zhu

Zhongshi Liu

Jian Chen

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

An ultrasonic-assisted method for preparing phosphatidylserine, comprising the following steps: adding 100-130 parts of phospholipid into a mixture of 150-200 parts of L-serine, 10-20 parts of anhydrous calcium chloride and 400-500 parts of pure water, adding 20-25 parts of phospholipase D for enzymatic hydrolysis reaction, and applying ultrasound in the enzymatic hydrolysis reaction for treatment. The present invention uses an ultrasonic treatment technology to assist phospholipase D to act on phosphatidylcholine and serine to undergo an enzymatic hydrolysis reaction to prepare phosphatidylserine, and at the same time, the ultrasonic frequency, ultrasonic intensity, ultrasonic power, ultrasonic time, ultrasonic temperature, enzyme activity and other parameters are controlled synergistically, so that the enzymatic hydrolysis conversion rate is 98% or higher.

Method for preparing phosphatidylserine by ultrasonic-assisted enzymatic hydrolysis

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

Jiangbo Li