Bacterial cross-feeding data

Nutritional interdependence is widespread within microbial communities. However, co-inoculation of most auxotrophic microorganisms often fails to establish stable metabolite exchange relationship. We used lysine and arginine auxotrophic <i>Escherichia coli</i> genotypes to examined their interactions over 25 days. Our results indicate that co-inoculation renders both amino acid production and utilization of auxotrophs unstable. We found that one strain (ΔL) consistently outcompeted the other (ΔA) due to faster metabolic responses. ΔL cells exhibited lysine utilization positively correlated with lysine production by ΔA, stabilizing their population size despite fluctuating lysine supply from ΔA. Conversely, ΔA individuals lack this metabolic pattern, resulting in the ΔL population exploiting the ΔA population. These findings highlight that metabolic asymmetries and specific utilization patterns destabilize microbial syntrophy. Our work underscores the importance of balanced metabolic exchanges for developing sustainable synthetic microbial consortia and offers insights into the evolutionary dynamics of microbial cooperation.营养互营现象在微生物群落中广泛存在。然而，对多数营养缺陷型微生物进行共接种时，往往难以建立稳定的代谢物交换关系。本研究使用赖氨酸缺陷型与精氨酸缺陷型大肠杆菌（Escherichia coli）基因型菌株，对其25天内的相互作用进行了观测。研究结果显示，共接种会导致营养缺陷型菌株的氨基酸产生与利用过程均变得不稳定。我们发现，其中一株（ΔL）始终较另一株（ΔA）更具竞争优势，这源于前者更快的代谢响应速率。ΔL菌株的赖氨酸利用速率与ΔA菌株产生的赖氨酸量呈正相关，即便ΔA菌株的赖氨酸供应存在波动，该关联仍能稳定ΔL的种群规模。与之相反，ΔA菌株并不具备这类代谢模式，最终导致ΔL种群对ΔA种群产生了利用性竞争。上述研究结果表明，代谢不对称性与特定的底物利用模式会破坏微生物互营关系的稳定性。本研究强调了平衡代谢交换对于构建可持续合成微生物群落的重要性，并为解析微生物合作的进化动力学提供了新视角。