Feedstock and Process Evidence for Engineering Assessment of Residue-Based Bacillus Surfactin Production

Abstract

Agro-industrial and food-processing residues have been investigated as alternative feedstocks for surfactin production by Bacillus, but published systems differ in biological configuration, feedstock conversion, medium formulation, reactor operation, oxygen-transfer measurements and product-recovery basis. This targeted engineering synthesis separates directly reported observations from cross-study interpretation. Evidence coverage differed by question: the DGS study directly documented feedstock-conversion dependence, whereas the brewery-trub oxygen-supply study provided reactor-scale oxygen-transfer measurements; direct ranking was not justified because the systems differed in biological, operational and measurement bases. Reported product titers and kLa values therefore required system-specific interpretation. The proposed evidence-to-inference workflow explicitly separates reporting status, comparability and evidence-supported inference, providing a structured basis for cross-system assessment without numerical robustness scores or industrial-performance prediction. It is a conceptual screening procedure rather than a validated predictive tool.