Jiangnan University

Shandong Runde Biotechnology Co., Ltd

Changfeng Liu

Jian Chen

Guocheng Du

Jianghua Li

Long Liu

Xueqin Lv

Jianxing Lu

Chen Deng

Jiangong Lu

Wei Lu

Hongzhi Zhang

Zhu Jiang

The present invention discloses a RamA transcription factor mutant for promoting the production of N-acetylglucosamine and use thereof. The mutant is obtained by mutating lysine at position 90 to asparagine and serine at position 92 to lysine in a parent having an amino acid sequence as shown in SEQ ID NO: 2. The present invention provides a genetically engineered strain that overexpresses the RamA transcription factor mutant and increases the production of N-acetylglucosamine. By overexpressing the transcription factor RamA that is involved in the regulation of carbon metabolism, the extracellular accumulation of N-acetylglucosamine is increased, with a maximum concentration reaching 31.5 g/L, which lays a foundation for further metabolic engineering ofto produce glucosamine. The method for constructing recombinantof the invention is simple, and convenient in use, and thus has good application prospects.

RamA transcription factor mutant for promoting production of N-acetylglucosamine and use thereof

The present invention provides a recombinantproducing N-acetylglucosamine and use thereof. The recombinantis obtained by overexpressing, in, the transcription factor SugR derived therefrom. The recombinantof the present invention increases the production of acetylglucosamine to up to 26 g/L, and lays a foundation for further metabolic engineering ofto produce glucosamine.

Transcription factor SugR coding gene, and use thereof in production of N-acetylglucosamine

The disclosure herein relates to construction and application of engineering bacteria capable of secreting and expressing diacetylchitobiose deacetylase, and belongs to the technical field of fermentation engineering. Firstly, recombinantcapable of heterologously secreting and expressing a diacetylchitobiose deacetylase gene is constructed, and a signal peptide fragment yncM is added into the recombinant vector for the first time. The signal peptide can secrete the target protein diacetylchitobiose deacetylase outside the cells of the recombinant, and a mutant of the 5'-end untranslated region is acquired, thereby significantly increasing the expression level of the target protein, and greatly simplifying the subsequent enzyme separation and purification steps. When the acquired diacetylchitobiose deacetylase is fermented and cultured in a fermentation medium for 50-60 h, the enzyme activity reaches a maximum of 1,548.7 U/mL, and the maximum yield of the diacetylchitobiose deacetylase is about 620 mg/L. Simultaneously, the method has the advantages of low production cost, mild production conditions, simple purification process steps, safe production operation and the like.

Construction and application of engineering bacteria capable of secreting and expressing diacetylchitobiose deacetylase

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Taian, China

Changfeng Liu