Feasibility of a 1,3-propanediol biorefinery from glycerol using a Clostridium butyricum wild-type strain and its in-silico knockout mutants: A genome-scale metabolic model integration

Advances in computational tools have enabled the development of genome-scale metabolic (GSM) models. Integrating GSM models with downstream processes through multi-scale models allows predicting biorefinery feasibility. This study utilizes the GSM model i Cbu641 to predict the use of the wild-type strain Clostridium butyricum IBUN 158B for producing 1,3-propanediol (PDO) from Colombian biodiesel-derived glycerol. Different bioreactor and evaporation trains were evaluated, with the selected biorefinery comprising a fed-batch bioreactor and double-effect evaporation trains. Economic evaluation indicates the selected biorefinery has a payout period of 7.4 years and a production cost of around 1 US$/kg, indicating feasibility. Five additional biorefineries were assessed using in-silico knockout mutants blocking competing co-products. Simulations revealed that blocking hydrogen production could reduce unit costs and payout periods by up to 15 %, suggesting its potential in a PDO biorefinery. Concluding, the novelty of this study is the holistic integration of biological and economic assessments, reducing resources in exploratory experiments. • Prediction of Clostridium butyricum growth using a genome-scale metabolic model. • Evaluation of bioreactor and evaporation train effects on biorefinery profitability. • Selected biorefinery may have costs of 1.02 US$/kg, making it economically feasible. • No-hydrogen production mutant may improve biorefinery profitability by up to 15 %. • Holistic analysis reduces costs by simulating optimal conditions pre-experiments.