高产（+）Y-内酰胺酶菌株LNH-5-3B发酵条件优化及其酶学特性

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中图分类号：TQ925 文献标志码：A doi： 10.3969/j .issn.1673-5862.2025.03.008

Fermentation conditions optimization and enzymatic characteristics of high yield （+）γ -lactamase strain LNH-5-3B

LIU Chunying1，2，3，4 ， GUO Xinzhi1，2，3，4 ， ZHANG Qing fang1，2.3，4 ， YU Shuang1，2，3，4 ， CHI Xuemei 1，2，3，4 ， CHI Naiyu1，2，3，4 （1. School of Life and Health，Dalian University，Dalian 116622，China；2. Liaoning Marine Microbiology Engineering Technology Research Center，Dalian 116622，China；3.Dalian Marine Microbiology Engineering Key Laboratory，Dalian 116622，China；4.Dalian Key Laboratory of Synthetic Biology，Dalian 116622，China）

Abstract： γ-lactam，an important pharmaceutical intermediate，exhibits chiral characteristics that adversely affect drug synthesis. By leveraging the selective catalytic properties of γ -lactamase， optically pure γ-lactam compounds can be synthesized. This study aimed to explore the optimal fermentation parameters for the strain LNH-5-3B，which produces （+）γ -lactamase. To achieve this，the culture conditions were systematically optimized，and a preliminary investigation into the enzymatic characteristics of this enzyme was conducted. In this experimental design，the PlackettBurman method was initially employed to identify three key variables： pH ，fermentation time，and rotational speed. Subsequently，the steepest ascent method was utilized to approach the peak region of enzyme activity，and the significant influencing factors were systematically optimized using the

Box-Behnken central composite design. The experimental results indicated that when the culture system was maintained at a pH of 7，fermentation lasted for 44h ，and the rotation speed was set at 200r/min ，the activity of （+）γ -lactamase reached 1493.92U/L ，representing a 15.8% increase over the initial conditions. This study not only elucidated the optimal culture parameters for the LNH-5-3B strain but also provided an initial insight into the biological characteristics of this enzyme，thereby laid a theoretical foundation for further research and industrial applications.

Key words ： （+）γ -lactamase；response surface；fermentation conditions optimization

内酰胺酶（EC3.5.2.-）作为酰胺酶（EC3.5.1.4）的一种，因其能够选择性降解工业上的外消旋 γ-内酰胺（CAS：49805-30-3）而得名。（剩余8805字）