The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 2021
Filed:
Jan. 24, 2019
Jiangnan University, Wuxi, CN;
Zhiming Rao, Wuxi, CN;
Xu Li, Wuxi, CN;
Xian Zhang, Wuxi, CN;
Shuqin Xu, Wuxi, CN;
Jingyi Hu, Wuxi, CN;
Meijuan Xu, Wuxi, CN;
Taowei Yang, Wuxi, CN;
Jiangnan University, Wuxi, CN;
Abstract
The present disclosure discloses a thermophilic L-asparaginase mutant and screening and fermentation methods thereof, and belongs to the field of gene engineering, enzyme engineering and fermentation engineering. In168, aCH1-derived L-asparaginase encoding gene is used as a template, and a mutation library is constructed by an error-prone PCR (epPCR) technology. A mutant strain with improved specific enzyme activity is screened through a high-flux screening method of synchronous cell disruption and enzyme activity measurement. Mutated residues included in a positive mutant are analyzed to construct a composite mutant strain S17G/A90S/R156S/K272A with improved specific enzyme activity and specific enzyme activity of 3108 U/mg. An expression quantity of the composite mutant strain in the168 is increased through measures of a strong promoter Pand RBS optimization. Finally, the168 with a gene of the L-asparaginase composite mutant strain is subjected to enzyme production fermentation in a 5 L fermentation tank through culture medium optimization and pH and feeding coupling strategies. The enzyme activity yield of the L-asparaginase is up to 6453+/−127 U/mL.