Jiangnan University

Shandong Runde Biotechnology Co., Ltd

Bright Dairy & Food Co., Ltd.

Inner Mongolia Mengniu Dairy (Group) Co., Ltd.

Xueqin Lv

Jian Chen

Guocheng Du

Jianghua Li

Long Liu

Changfeng Liu

Jianxing Lu

Jieying Deng

Chen Deng

Jiangong Lu

Yanfeng Liu

Wei Lu

Chunmei Chen

Miao Wang

Zhu Jiang

Xiaomin Dong

Wenyang Wu

Hongzhi Zhang

Guolin Zhou

Chenyang Zhang

Ke Liu

Li Sun

Xianhao Xu

The invention provides astrain for producing a human milk lipid substitute. By integrating a heterologous lysophosphatidic acid acyltransferase intoand knocking out its own natural lysophosphatidic acid acyltransferase, the content of palmitic acid (C16:0) at Sn-2 position of triacylglycerol produced byis increased, to synthesize a human milk lipid substitute. On this basis, a metabolic pathway related gene is knocked out, to further increase the content of human milk lipid substitute in the product. In the present invention, a human milk lipid substitute is de novo synthesized byfor the first time, in which the total fatty acid is 15% or more, and the relative content of C16:0 at Sn-2 position reaches about 60%.

strain for producing human milk lipid substitute and use thereof

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 disclosure discloses recombinantfor synthesizing e lacto-N-neotetraose yield. The recombinantis obtained by integrating two &#x3b2;-1,4-galactotransferase genes on a genome of a host bacterium168&#x394;amyE:P-lacY, P-lgtB, P-comK and exogenously expressing a &#x3b2;-1,3-N-glucosaminotransferase gene. Compared with a strain before transformation, the recombinantof the disclosure improves the yield of the synthesized lacto-N-neotetraose from 720 mg/L to 1300 mg/L, laying a foundation for further metabolic engineering transformation offor producing the lacto-N-neotetraose.

Recombinantfor synthesizing lacto-N-neotetraose and application thereof

The present invention provides a pyruvate-responsive biosensor and a construction method and use thereof. In the present invention, pyruvate-responsive biosensors with different dynamic ranges are successfully constructed by optimizing the PdhR binding sequence inserted on the P43 promoter and optimizing the insertion site, wherein the minimum increase in dynamic range is by 0.6 time, and the maximum increase is by 30.7 times. The pyruvate-responsive biosensors are useful in the precise control of the expression of each gene in the cell. Since pyruvate is a key metabolite of central carbon in the cells, these biosensors are capable of dynamically regulating the expression level of intracellular genes according to changes in the content of pyruvate in the cells, thereby achieving the dynamic control of intracellular metabolic flux. The pyruvate biosensor obtained in the present invention has a good specificity, and a response range to pyruvate of 10-35 nmol/g DCW.

Pyruvate-responsive biosensor, and construction method and use thereof

The present invention provides an acid-tolerantstrain and use thereof. By using exogenously added malic acid as a stress, an acid-tolerant mutantstrain MTPfo-4 is obtained by directed evolution screening in the laboratory, which tolerates a minimum pH of 2.44. The mutant strain MTPfo-4, tolerant to multiple organic acids, has an increased tolerance to exogenous malic acid of up to 86.6 g/L. The mutant strain MTPfo-4 obtained is further identified. The mutant strain grows stably and well, and can tolerate a variety of organic acids (lactic acid, malic acid, succinic acid, fumaric acid, citric acid, gluconic acid, and tartaric acid). It also has a strong tolerance to inorganic acids (HCl and HPO). This is difficult to achieve in the existing research and reports of. The strain is intended to be used as an acid-tolerant chassis cell factory for producing various short-chain organic acids.

Acid-tolerantand use thereof

The disclosure discloses recombinantfor synthesizing guanosine diphosphate fucose and a construction method and application thereof. The recombinantis obtained by intensively expressing guanylate kinase and nucleotide diphosphokinase genes and expressing exogenous fucokinase and phosphate guanylyltransferase genes in a genome of168. According to the disclosure, a bacterial strain for synthesizing the guanosine diphosphate fucose is obtained by reconstructing the168, with a volume of intracellular accumulation up to 196.15 g/L. According to the disclosure, by intensively expressing the guanylate kinase and nucleotide diphosphokinase genes, and enhancing the supply of intracellular GDP-L-fucose composition cofactors, the synthesis of the guanosine diphosphate fucose is promoted. The construction method for the recombinantof the disclosure is simple and convenient to use, thus having good application prospects.

Recombinantfor synthesizing GDP-L-fucose and application 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 present invention provides a recombinantwith improved 2'-fucosyllactose production, and a construction method thereof. In the present invention, a strain capable of efficiently synthesizing 2&#x2032;-fucosyllactose is obtained by the fusion expression of the fucosyltransferase gene and the L-fucokinase/guanosine 5&#x2032;-diphosphate-L-fucose pyrophosphorylase gene inBSGL-FF, the fermentation supernatant of which comprises a cumulative amount of 2&#x2032;-fucosyllactose as high as 1.62 g/L, which is 55% higher than the amount achieved with the control strain. The construction method of the recombinantof the present invention is simple, and convenient to use, and thus has good application prospects.

Recombinantwith improved 2'-fucosyllactose production, and construction method thereof

The invention provides a recombinant, construction method and use thereof, wherein the cell's own FMMs are used as a space scaffold, and a multi-enzyme complex is constructed from specific marker proteins FloA and FloT, such that an artificial substrate channel is formed, and the cell metabolic burden is effectively reduced. The recombinantof the invention can efficiently synthesize GlcNAc without affecting cell life activity, and can also limit the toxic intermediate metabolite GlcN-6-P near the plasma membrane to reduce or eliminate its inhibition on cell activity. In the process of shaking flask fermentation using complex medium, the yield of acetyl glucosamine of the control strain BSG-C was only 0.45 g&#xb7;L, while that of BSG-AT, BSG-ATP, BSG-ATPB increased to 5.29 g&#xb7;L, 6.22 g&#xb7;Land 8.48 g&#xb7;Lrespectively. The construction method of recombinantis simple, easy to use and has a good application prospect.

Recombinantand use thereof

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.

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Wuxi, China

Xueqin Lv