Application of explainable machine learning in the production of pullulan by Aureobasidium pullulans CGMCCNO.7055.

Journal: International journal of biological macromolecules
PMID:

Abstract

The application of machine learning in pullulan biofermentation has demonstrated significant potential. Explainable machine learning enhances model transparency and interpretability by revealing the relationships between variables. In this study, we compared the predictive performance of six machine learning models. The Categorical Boosting (CatBoost) model demonstrated the best fit for biomass and pullulan molecular weight, while eXtreme Gradient Boosting (XGBoost) excelled in predicting pullulan production. Additionally, feature importance and SHapley Additive exPlanations (SHAP) analyses visualized the complex relationships between medium conditions and objectives. Yeast extract emerged as the most influential factor for all three targets. Meanwhile, NaCl and initial pH showed potential in regulating pullulan production and molecular weight, respectively. Finally, optimal medium conditions for maximizing biomass, pullulan production, and molecular weight were determined using the Non-dominated Sorting Genetic Algorithm III (NSGA-III) algorithm, achieving a maximum integrated optimization rate of 275.08 % (calculated as the average of improvements across the three objectives). This study effectively expands the application of the NSGA-III algorithm in multi-objective optimization for pullulan production. These findings contribute to advancing the application of explainable machine learning and advanced intelligent algorithms in the field of pullulan production.

Authors

  • Shiwei Chen
    State Key Laboratory of Bio-based Fiber Materials, Tianjin University of Science and Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, China; Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, School of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
  • Wenmin Li
    State Key Laboratory of Bio-based Fiber Materials, Tianjin University of Science and Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, China; Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, School of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
  • Xiaowen Zhao
    State Key Laboratory of Bio-based Fiber Materials, Tianjin University of Science and Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, China; Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, School of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
  • Miaoxin Li
    Center for Precision Medicine and Department of Genetics and Biomedical Informatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
  • Tingbin Zhao
    Tianjin Huizhi Biotrans Bioengineering Co., Ltd., Tianjin 300457, China.
  • Guobao Zheng
    Institute of Forestry Sciences Agricultural Biotechnology Research Center, Ningxia Academy of Agriculture and Forestry Science, Yinchuan 750002, China.
  • Weifeng Cao
    State Key Laboratory of Bio-based Fiber Materials, Tianjin University of Science and Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, China; Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, School of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China. Electronic address: wfcao@tust.edu.cn.
  • Changsheng Qiao
    State Key Laboratory of Bio-based Fiber Materials, Tianjin University of Science and Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, China; Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, School of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Huizhi Biotrans Bioengineering Co., Ltd., Tianjin 300457, China. Electronic address: qiaochangsheng@tust.edu.cn.