Explainable machine learning-driven predictive performance and process parameter optimization for caproic acid production.

Journal: Bioresource technology
PMID:

Abstract

In this study, four machine learning (ML) prediction models were developed to predict and optimize the production performance of caproic acid based on substrates, products, and process parameters. The XGBoost outperformed others, with a high R of 0.998 on the training set and 0.885 on the test set. Feature importance analysis revealed hydraulic retention time (HRT) and butyric acid concentration are decisive. The SHAP method offered profound insights into the interplay and cumulative effects of substrate composition, identified the synergistic effects between butyric acid and lactic acid, and emphasized adding glucose can benefit caproic with lactic acid co-fermentation. By integrating the Adaptive Variation Particle Swarm Optimization (AVPSO) algorithm, the optimal process conditions to achieve a maximum caproic acid production of 8.64 g/L was obtained. This study not only advances caproic acid production but contributes a versatile ML-driven strategy applicable to bioprocess optimizations, potentially transformative for sustainable and economically viable bioproduction.

Authors

  • Hongzhi Ma
    Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, 100083, China; Xinjiang Key Laboratory of Clean Conversion and High Value Utilization of Biomass Resources, School of Resource and Environmental Science, Yili Normal University, Yining 835000, China. Electronic address: mahongzhi@ustb.edu.cn.
  • Yichan Liu
    Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, 100083, China.
  • Jihua Zhao
    Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, 100083, China.
  • Fan Fei
    College of Public Administration, Huazhong University of Science and Technology, China.
  • Ming Gao
    State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
  • Qunhui Wang
    Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, 100083, China.