The present invention relates to glucoamylase variants having improved thermostability. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

The present invention relates to glucoamylase variants having improved thermostability. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

A method for separating amoxicillin and phenylacetic acid from reaction solution in one-step enzymatic synthesis of amoxicillin is provided. The method employs immobilized penicillin acylase mutant to catalyze the one-step synthesis of amoxicillin from penicillin potassium, and develops a separation process for the resulting reaction mixture. The technical scheme mainly comprises: Firstly separating the immobilized penicillin acylase mutant from the reaction solution through filtration; subsequently isolating amoxicillin via crystallization; followed by separating and recovering phenylacetic acid through toluene extraction and back extraction. This separation method enables rapid and efficient isolation of amoxicillin with high production yield, achieving an average crystallization rate of 93.22%. Concurrently, it demonstrates effective separation and recovery of phenylacetic acid while allowing recyclable use of the toluene extractant.

A method for separating amoxicillin and phenylacetic acid from reaction solution in one-step enzymatic synthesis of amoxicillin is provided. The method employs immobilized penicillin acylase mutant to catalyze the one-step synthesis of amoxicillin from penicillin potassium, and develops a separation process for the resulting reaction mixture. The technical scheme mainly comprises: Firstly separating the immobilized penicillin acylase mutant from the reaction solution through filtration; subsequently isolating amoxicillin via crystallization; followed by separating and recovering phenylacetic acid through toluene extraction and back extraction. This separation method enables rapid and efficient isolation of amoxicillin with high production yield, achieving an average crystallization rate of 93.22%. Concurrently, it demonstrates effective separation and recovery of phenylacetic acid while allowing recyclable use of the toluene extractant.

A one-step method for synthesizing amoxicillin from penicillin or a salt thereof through an enzyme catalysis is provided. Conventional amoxicillin production requires sequential use of distinct penicillin acylases for hydrolysis and synthesis steps, necessitating isolation of the intermediate 6-aminopenicillanic acid (6-APA) and resulting in elevated manufacturing costs and suboptimal process efficiency. To address these limitations, the inventive method utilizes a mutant of penicillin acylase derived from Kluyvera citrophila as the exclusive biocatalyst in an aqueous reaction system. By reacting penicillin G potassium salt with D-p-hydroxyphenylglycine methyl ester, the process achieves direct amoxicillin synthesis in a single enzymatic step, attaining a product yield of 99%. This method exhibits advantages including fast catalytic rate, high product yield, environmentally friendly pure aqueous reaction system, low cost, and excellent economic benefits.

A one-step method for synthesizing amoxicillin from penicillin or a salt thereof through an enzyme catalysis is provided. Conventional amoxicillin production requires sequential use of distinct penicillin acylases for hydrolysis and synthesis steps, necessitating isolation of the intermediate 6-aminopenicillanic acid (6-APA) and resulting in elevated manufacturing costs and suboptimal process efficiency. To address these limitations, the inventive method utilizes a mutant of penicillin acylase derived from Kluyvera citrophila as the exclusive biocatalyst in an aqueous reaction system. By reacting penicillin G potassium salt with D-p-hydroxyphenylglycine methyl ester, the process achieves direct amoxicillin synthesis in a single enzymatic step, attaining a product yield of 99%. This method exhibits advantages including fast catalytic rate, high product yield, environmentally friendly pure aqueous reaction system, low cost, and excellent economic benefits.

A mutant penicillin acylase and uses thereof are provided. Compared to the amino acid sequence set forth in SEQ ID NO: 1, the mutant includes at least one mutation selected from the group consisting of: F146K, F24R, F71Y, N241K, G385Y, and G385R. By introducing mutations into the penicillin acylase derived from Kluyvera citrophila, the invention obtains a mutant enzyme exhibiting enhanced and well-coordinated hydrolytic and synthetic activities. It can be used for the synthesis of -lactam antibiotics, particularly for the one-step preparation of amoxicillin from penicillin potassium salt, thereby avoiding the isolation of the intermediate 6-APA. The present invention provides a key enzyme for the efficient production of -lactam antibiotics and is poised to significantly advance the innovation of their manufacturing technology.

A mutant penicillin acylase and uses thereof are provided. Compared to the amino acid sequence set forth in SEQ ID NO: 1, the mutant includes at least one mutation selected from the group consisting of: F146K, F24R, F71Y, N241K, G385Y, and G385R. By introducing mutations into the penicillin acylase derived from Kluyvera citrophila, the invention obtains a mutant enzyme exhibiting enhanced and well-coordinated hydrolytic and synthetic activities. It can be used for the synthesis of -lactam antibiotics, particularly for the one-step preparation of amoxicillin from penicillin potassium salt, thereby avoiding the isolation of the intermediate 6-APA. The present invention provides a key enzyme for the efficient production of -lactam antibiotics and is poised to significantly advance the innovation of their manufacturing technology.