Pseudomonas-saccharomyces interactions:: Influence of fungal metabolism on bacterial physiology and survival
Pseudomonas-saccharomyces interactions:: Influence of fungal metabolism on bacterial physiology and survival
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DOI：
10.1128/jb.187.3.940-948.2005
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发表时间：
2005-02-01
影响因子：
3.2
通讯作者：
Kolter, R
中科院分区：
文献类型：
--
作者：
Romano, JD;Kolter, R
真菌与细菌的相互作用无处不在，但它们的分子基础却知之甚少。在这项研究中，鉴定了一株恶臭假单胞菌和酿酒酵母菌之间的一种新的有益相互作用。当细菌单独在葡萄汁或含有不同浓度葡萄糖的合成培养基中孵育时，它们在固定阶段迅速失去活力。然而，当细菌在真菌存在的培养基中孵育时，它们的固定相存活率显著提高。在含有葡萄糖的琼脂板上，真菌的有益作用表现在强健的细菌生长和胞外多糖的产生，导致明显的粘液样变性。相反，在没有真菌的情况下，细菌在这种培养基中生长得很差，而且是非粘液样的。利用现有的酿酒酵母缺失文库，鉴定了无法介导这种有益相互作用的酵母突变体。这些突变表明，真菌代谢可利用葡萄糖的能力及其对培养基ph的影响介导了对细菌生理和生存的有益影响。在葡萄糖浓度高的自然环境中，真菌的存在很可能在其自然历史中对某些恶臭假单胞菌菌株的生理和生存产生了深远的有益影响。
Fungal-bacterial interactions are ubiquitous, yet their molecular basis is only poorly understood. In this study, a novel beneficial interaction between a strain of Pseudomonas putida and the fungus Saccharomyces cerevisiae was identified. When the bacteria were incubated alone in grape juice or in synthetic medium containing various concentrations of glucose, they lost viability rapidly during stationary phase. However, when the bacteria were incubated in these media in the presence of the fungus, their stationary phase survival improved dramatically. On agar plates containing glucose, the beneficial effects of the fungus were manifested in robust bacterial growth and exopolysaccharide production that led to visible mucoidy. In contrast, bacteria grew poorly and were nonmucoid in such media in the absence of the fungus. By using the available S. cerevisiae deletion library, yeast mutants that were unable to mediate this beneficial interaction were identified. These mutants revealed that the beneficial effect on bacterial physiology and survival was mediated by the ability of the fungus to metabolize the available glucose and consequent effects on the medium's pH. In natural environments where the concentration of glucose is high, it is likely that the presence of fungi has had profound beneficial effects on the physiology and survival of certain P. putida strains throughout their natural history.