Optimization of scleroglucan production by Sclerotium rolfsii by lowering pH during fermentation via oxalate metabolic pathway manipulation using CRISPR/Cas9

Abstract Background Sclerotium rolfsii is a potent producer of many secondary metabolites, one which like scleroglucan an exopolysaccharide (EPS) appreciated as multipurpose compound applicable in industrial fields. Results Aspartate transaminase ( AAT1 ) catalyzes the interconversion aspartate and α-ketoglutarate to glutamate oxaloacetate. We selected oxalate metabolic pathway target CRISPR/Cas9. Disruption leads accumulation oxalate, rather than its conversion (AKG). Therefore, AAT1-mutant serves lower pH (pH 3–4) so increase production pH-sensitive metabolite 21.03 g L −1 with productivity up 0.25 ·h . Conclusions established platform for gene editing that could rapidly generate select mutants provide new beneficial strain S. hyper-producer, expected reduce cost controlling optimum condition fermentation industry.