Araoz Mario, Grillo-Puertas Mariana, de Moreno de LeBlanc Alejandra, Hebert Elvira María, Villegas Josefina María, Rapisarda Viviana Andrea
Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica, "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, San Miguel de Tucumán, Argentina.
Centro de Referencia para Lactobacilos (CERELA-CONICET), San Miguel de Tucumán, Argentina.
Front Microbiol. 2024 Feb 27;15:1343541. doi: 10.3389/fmicb.2024.1343541. eCollection 2024.
Inorganic phosphate (Pi) concentration modulates polyphosphate (polyP) levels in diverse bacteria, affecting their physiology and survival. CRL 1905 is a lactic acid bacterium isolated from quinoa sourdough with biotechnological potential as starter, for initiating fermentation processes in food, and as antimicrobial-producing organism. The aim of this work was to evaluate the influence of the environmental Pi concentration on different physiological and molecular aspects of the CRL 1905 strain. Cells grown in a chemically defined medium containing high Pi (CDM + P) maintained elevated polyP levels up to late stationary phase and showed an enhanced bacterial survival and tolerance to oxidative stress. In Pi sufficiency condition (CDM-P), cells were ~ 25% longer than those grown in CDM + P, presented membrane vesicles and a ~ 3-fold higher capacity to form biofilm. Proteomic analysis indicated that proteins involved in the "carbohydrate transport and metabolism" and "energy production and conversion" categories were up-regulated in high Pi stationary phase cells, implying an active metabolism in this condition. On the other hand, stress-related chaperones and enzymes involved in cell surface modification were up-regulated in the CDM-P medium. Our results provide new insights to understand the CRL 1905 adaptations in response to differential Pi conditions. The adjustment of environmental Pi concentration constitutes a simple strategy to improve the cellular fitness of CRL 1905, which would benefit its potential as a microbial cell factory.
无机磷酸盐（Pi）浓度可调节多种细菌中的多聚磷酸盐（polyP）水平，影响其生理功能和生存能力。CRL 1905是一种从藜麦酸面团中分离出的乳酸菌，具有作为发酵剂启动食品发酵过程以及作为抗菌剂产生菌的生物技术潜力。这项工作的目的是评估环境Pi浓度对CRL 1905菌株不同生理和分子方面的影响。在含有高Pi的化学限定培养基（CDM + P）中生长的细胞在稳定期末期之前一直保持较高的多聚磷酸盐水平，并表现出增强的细菌存活率和对氧化应激的耐受性。在Pi充足的条件下（CDM-P），细胞比在CDM + P中生长的细胞长约25%，呈现出膜泡，形成生物膜的能力高出约3倍。蛋白质组学分析表明，参与“碳水化合物转运和代谢”以及“能量产生和转换”类别的蛋白质在高Pi稳定期细胞中上调，这意味着在此条件下有活跃的代谢。另一方面，与应激相关的伴侣蛋白和参与细胞表面修饰的酶在CDM-P培养基中上调。我们的结果为理解CRL 1905对不同Pi条件的适应性提供了新的见解。调整环境Pi浓度是提高CRL 生1905细胞适应性的一种简单策略，这将有利于其作为微生物细胞工厂的潜力。
