Tianjin University of Science and Technology

Shandong Lonct Enzymes Co. Ltd

Fuping Lu

Zhengxiang Wang

Dandan Niu

Kangming Tian

Yu Li

Wenlong Liu

Fufeng Liu

Xingji Wang

Kefen Wang

Yihan Liu

Huitu Zhang

Chunli Shen

The disclosure discloses a method for producing α-calcium sulfate hemihydrate whiskers by using fermentation broth for producing lactic acid with a calcium salt method as a raw material and synchronously recovering a lactic acid monomer. The method comprises the following steps: 1) after fermentation of lactic acid is ended, heating fermentation broth; 2) stirring, and adding sulfuric acid for reaction; 3) after the reaction is ended, filtering and collecting a solid part, namely α-calcium sulfite hemihydrate whiskers, and collecting a liquid part, namely a free lactic acid solution containing the lactic acid monomer; and 4) washing and drying the obtained α-calcium sulfate hemihydrate whiskers to obtain a α-calcium sulfate hemihydrate whisker finished product, filtering and concentrating the obtained free lactic acid solution to obtain a lactic acid crude product, and refining the lactic acid crude product to obtain a high-purity lactic acid monomer. The disclosure can replace the efficient separation of lactic acid in production of lactic acid with the existing calcium salt method and high value-added transformation of a calcium sulfite byproduct, thereby significantly reducing the refining cost of lactic acid and formation of wastes and facilitating improvement of lactic acid production quality and simplification of a post-extraction process technology.

Method for producing calcium sulfate hemihydrate whiskers by using fermentation broth for producing lactic acid with calcium salt method as raw material and synchronously recovering lactic acid monomer

An alkaline protease mutant, and a gene, engineered strain, a preparation method and application thereof are provided. The method comprises the following steps of extracting genome DNA of, performing PCR amplification to obtain a wild-type alkaline protease gene sequence, mutating the wild-type alkaline protease gene obtained by the amplification through an error-prone PCR, performing high-throughput screening to obtain a plurality of highly active alkaline protease genes, performing DNA shuffling on the highly active alkaline protease genes, and performing screening to obtain eight alkaline protease mutant genes with higher activity.

Alkaline protease mutant, and gene, engineered strain, preparation method and application thereof

Disclosed are very high optically pure D- and L-lactic acid fermentation production strains and construction methods thereof and the method for preparing very high optically pure D- and L-lactic acids using the strains, wherein the deposit number of the D-lactic acid fermentation production strain is CGMCC No. 11059, and the deposit number of the L-lactic acid fermentation production strain is CGMCC No. 11060.

Polymer grade lactic acid monomer production bacteria and construction method thereof and technology for manufacturing lactic acid

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Tianjin, China

Fuping Lu