Genome-Scale Community Models for Designing Efficient Lignocellulolytic Bacterial Consortia Using Bovine Rumen...

Bovine rumen microbial communities play an important role in degrading lignocellulosic biomass and generating value-added products through synergistic metabolic activity. Hence, examining this microbial community may offer valuable insights into enhancing lignocellulose degradation and biofuel production machinery. However, microbial diversity with varying metabolic interactions within the bovine rumen community niche poses a challenge to designing mutualistic consortia. A comprehensive understanding of microbial interactions, growth compatibility, and metabolic synergy is crucial for the development of mutualistic synthetic consortia. Here, we have used six bovine rumen microbial strains to evaluate interspecies interactions, pairwise growth compatibility, and coculture-based lignocellulose degradation activities. Flux-based parameters, such as pairwise metabolic assistance (PMA) and growth support index (PGSI), were employed to investigate the coculture-based growth and metabolic synergies. The pairwise in silico assessments helped to predict 11 compatible microbial communities, which were subsequently validated by experimentally grown coculture systems. The enzymatic synergism (DES) of some experimentally grown pairs showed a higher correlation with the model-derived PMA, demonstrating the consistency of the overall prediction. The highest degree of enzymatic synergism has been achieved through the pairwise coculture of Butyrivibrio fibrisolvens and Selenomonas ruminantium, resulting in a 41% increase in the endoglucanase activity. Further investigation of three-membered communities showed that a combination of B. fibrisolvens, S. ruminantium, and Ruminococcus albus exhibited synergistic activity across all lignocellulosic substrates, suggesting the strong metabolic interplay between compatible species. Therefore, the in silico assessment of microbial interactions helped to identify suitable combinations with increased lignocellulolytic activity. The community-model-based study can provide a framework for designing synthetic microbial consortia with potential applications in biofuel production, enzymatic degradation, and other biotechnological studies.