Joint Transcriptomic and Metabolomic Analysis of Early Adaptation Strategies of Klebsiella variabilis KV1 under Bamboo Powder Conditions
Bamboo powder, as a dense lignocellulosic substrate, subjects microorganisms to early adaptive stress rather than efficient degradation processes during survival. This study investigated Klebsiella variabilis LS1, derived from the gut of the giant bamboo elephant , by comparing its growth phenotypes and multi-omics characteristics under bamboo powder (KVB) versus molasses (KVT) conditions to elucidate its early response mechanisms. Results demonstrated that LS1 exhibited "limited early growth" under bamboo powder conditions. Transcriptomic analysis revealed significant downregulation of key ABC transporter genes (ugpQ) and respiratory chain genes (ccmA), while metabolomic analysis confirmed reprogramming of the tryptophan metabolic pathway and substantial accumulation of downstream metabolites such as allantoin and serotonin. These findings indicate that LS1s initial utilization of bamboo powder does not solely enhance degradation activity but rather employs an adaptive reprogramming strategy- "inhibiting high-energy-consuming transport and remodeling tryptophan homeostasis" -to cope with energy-constrained environments.