(717d) Elucidating the Robustness of Bacillus Coagulans B-768 for Biomanufacturing: Insights from Phenotypic Profiling, Functional Genomics, and Proteome Reallocation

Bacillus coagulans is a promising microbial platform for biomanufacturing due to its robustness and ability to utilize lignocellulosic biomass hydrolysates, yet its cellular mechanisms remain underexplored. To address this shortcoming, the metabolic versatility and robustness of a novel, undomesticated strain, B. coagulans B-768, were explored through phenotypic characterization, functional genomics, and quantitative proteomics. Genome sequencing revealed B-768 possesses the largest known B. coagulans genome (3.94 Mbp), enriched with carbohydrate metabolism genes that enable efficient utilization of C5 (xylose, arabinose), C6 (glucose, mannose, galactose), and C12 (cellobiose) sugars. Experimental validation confirmed B-768's ability to grow on these carbon sources, as well as inhibitory switchgrass hydrolysate, exhibiting hierarchical sugar utilization with glucose as the preferred substrate. Quantitative proteomics elucidated distinct proteome reallocation strategies for different carbon substrates, with faster glucose uptake driving lactate overflow metabolism (up to 60 g/L at 92.7% theoretical yield), while slower xylose assimilation prioritized energy production over lactate synthesis. These findings highlight the role of coordinated gene regulation and proteome dynamics in B-768's robustness, positioning it as a versatile platform for producing chemicals and fuels from biomass. This work provides a foundation for engineering B. coagulans for optimized bioprocessing applications, addressing key challenges in sustainable biomanufacturing.