Cecconi Daniela, Milli Alberto, Rinalducci Sara, Zolla Lello, Zapparoli Giacomo
Dipartimento di Biotecnologie, University of Verona, Verona, Italy.
Dipartimento di Scienze Ambientali, University of Tuscia, Viterbo, Italy.
Electrophoresis. 2009 Sep;30(17):2988-2995. doi: 10.1002/elps.200900228.
Cultures of Oenococcus oeni, the most important malolactic bacterium, are used to induce malolactic fermentation in wine. Survival assays in two different wines confirmed that cells acclimated for 24 h in half-strength wine-like medium (acclimation medium) enhanced the malolactic performances. To investigate the effect of the pre-incubation phase on cell physiology, a proteomic study was carried out. Total protein extracts of acclimated and non-acclimated cell cultures (control) were analyzed by 2-D-PAGE. A total of 20 out of approximately 400 spots varied significantly. All the spots were identified by MS analysis and most of them were proteins involved in metabolism, transcription/translation processes and stress response. The results revealed the different physiological status between non-acclimated and acclimated cells explaining, in part, their different behavior in wine. Regulation of stress proteins such as heat and cold shock proteins was involved. Moreover, the availability of sugars and amino acids (even if at low concentration) in acclimation medium determined a modulation of energy metabolism enhancing the resistance to stressful conditions (as those that cells find in wine when inoculated). Finally, this proteomic study increased knowledge concerning the physiological changes in freeze-dried culture occurring with pre-inoculation procedures.
酒类酒球菌是最重要的苹果酸 - 乳酸细菌，其培养物用于诱导葡萄酒中的苹果酸 - 乳酸发酵。在两种不同葡萄酒中的存活试验证实，在半强度葡萄酒样培养基（驯化培养基）中驯化24小时的细胞提高了苹果酸 - 乳酸发酵性能。为了研究预培养阶段对细胞生理的影响，开展了一项蛋白质组学研究。通过二维聚丙烯酰胺凝胶电泳分析驯化和未驯化细胞培养物（对照）的总蛋白提取物。大约400个斑点中共有20个斑点有显著差异。所有斑点均通过质谱分析鉴定，其中大多数是参与代谢、转录/翻译过程和应激反应的蛋白质。结果揭示了未驯化细胞和驯化细胞之间不同的生理状态，部分解释了它们在葡萄酒中的不同行为。涉及应激蛋白如热休克蛋白和冷休克蛋白的调控。此外，驯化培养基中糖和氨基酸的可用性（即使浓度较低）决定了能量代谢的调节，增强了对压力条件的抗性（如接种后细胞在葡萄酒中遇到的压力条件）。最后，这项蛋白质组学研究增加了关于冻干培养物在接种前程序中发生的生理变化的知识。
