Kluyver Centre for Genomics of Industrial Fermentations, Delft, The Netherlands.
Mol Syst Biol. 2010 Sep 21;6:413. doi: 10.1038/msb.2010.67.
Situations of extremely low substrate availability, resulting in slow growth, are common in natural environments. To mimic these conditions, Lactobacillus plantarum was grown in a carbon-limited retentostat with complete biomass retention. The physiology of extremely slow-growing L. plantarum--as studied by genome-scale modeling and transcriptomics--was fundamentally different from that of stationary-phase cells. Stress resistance mechanisms were not massively induced during transition to extremely slow growth. The energy-generating metabolism was remarkably stable and remained largely based on the conversion of glucose to lactate. The combination of metabolic and transcriptomic analyses revealed behaviors involved in interactions with the environment, more particularly with plants: production of plant hormones or precursors thereof, and preparedness for the utilization of plant-derived substrates. Accordingly, the production of compounds interfering with plant root development was demonstrated in slow-growing L. plantarum. Thus, conditions of slow growth and limited substrate availability seem to trigger a plant environment-like response, even in the absence of plant-derived material, suggesting that this might constitute an intrinsic behavior in L. plantarum.
在自然环境中，底物可用性极低导致生长缓慢的情况很常见。为了模拟这些条件，将植物乳杆菌在具有完全生物质保留的碳限制滞留器中进行生长。通过基因组规模建模和转录组学研究，极度缓慢生长的植物乳杆菌的生理学与静止期细胞的生理学有根本的不同。在向极慢生长的过渡过程中，并没有大量诱导应激抵抗机制。产能代谢非常稳定，并且仍然主要基于葡萄糖转化为乳酸。代谢和转录组分析的结合揭示了与环境（特别是与植物）相互作用的行为：植物激素或其前体的产生，以及准备利用植物来源的底物。因此，在生长缓慢的植物乳杆菌中证明了干扰植物根发育的化合物的产生。因此，即使在没有植物衍生材料的情况下，缓慢生长和有限的底物可用性似乎也会引发类似于植物环境的反应，这表明这可能构成植物乳杆菌的内在行为。
