A pH-stable alkaline pectate lyase produced by the newly identified strain Bacillus altitudinis CAS-WZS-08

Objectives: Thermal and pH stabilities are extremely important for the application of pectate lyase. In this study, we aimed to obtain a strain that is able to produce pectate lyase with good pH stability.Methods: In this study, screening for pectate lyase was performed using plate assays. Fermentation parameters for pectate lyase production were optimized utilizing a single variable optimization. To get insight into the pectate lyase, its enzyme property, purification, identification, and application were performed.Results: Bacillus altitudinis CAS-WZS-08, producing pectate lyase with good pH stability, was isolated. The optimal fermentation conditions of CAS-WZS-08 are 4 g/L pectin, 20 g/L yeast extract, 2% inoculum size, pH 7.0, and 33 & DEG;C, which the production of pectate lyase can reach up to 0.71 & PLUSMN; 0.001 U/mL. The optimal pH and temperature of the pectate lyase were 10.0 and 60 & DEG;C, respectively. Stored at 4 & DEG;C, the pectate lyase was able to keep its full enzyme activity for 24 h under a wide range of pH (4.0-10.0) condition. With pH 10.0, this pectate lyase was stable under 30-45 & DEG;C. In addition, it can be activated by Mn2+, Cu2+, Co2+, and Ca2+, while inhibited by Fe3+, Ba2+, and Mg2+. Later, the electrophoretic pure protein was acquired through ammonium sulfate precipitation, cation exchange column, and Sephadex G-75. Liquid chromatography tandem-mass spectrometry (LC/MS-MS) further confirmed that the purified protein was pectate lyase with a molecular weight of ti 40 kDa. At last, the result of pectate lyase in extracting apple juice demonstrated that it has an excellent juice extraction ability.Conclusion: This study provides an excellent pH-stable pectate lyase with good thermal stability that is a potential candidate for industrial applications.& COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study aimed to obtain a strain capable of producing pectate lyase with good pH stability. Bacillus altitudinis CAS-WZS-08, producing pectate lyase with good pH stability, was isolated. The optimal fermentation conditions for pectate lyase production were determined, and the purified protein was identified as pectate lyase with excellent juice extraction ability.