Para-Aminobenzoic Acid, Calcium, and c-di-GMP Induce Formation of Cohesive, Syp-Polysaccharide-Dependent Biofilms in Vibrio fischeri.
Para-Aminobenzoic Acid, Calcium, and c-di-GMP Induce Formation of Cohesive, Syp-Polysaccharide-Dependent Biofilms in Vibrio fischeri.
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DOI：
10.1128/mbio.02034-21
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发表时间：
2021-10-26
期刊：
影响因子：
6.4
通讯作者：
Visick KL
中科院分区：
文献类型：
--
作者：
Dial CN;Speare L;Sharpe GC;Gifford SM;Septer AN;Visick KL
海洋细菌费氏弧菌（Vibrio fischeri）通过产生依赖于共生多糖（SYP）的瞬时生物膜，有效地定植其共生乌贼宿主Euprymna scolopes。然而，野生型菌株ES114在体外不能形成syp依赖性生物膜。相反，基因工程菌株，比如那些缺乏负调节因子BinK的菌株，已经被开发出来研究这种现象。从历史上看，费氏弧菌是用LBS培养的，LBS是一种含有色氨酸和酵母提取物的复杂培养基；需要补充钙来诱导binK突变体形成生物膜。在这里，通过我们发现酵母提取物抑制生物膜的形成，我们揭示了控制V. fischeri生物膜形成的信号和潜在机制。与在未补充的LBS上无法形成生物膜相反，binK突变体在缺乏酵母提取物的tTBS上形成了内聚的、syp依赖性的集落生物膜。此外，野生型菌株ES114在同时添加钙和维生素对氨基苯甲酸（pABA）的tTBS中生长时，能够熟练地形成内聚的syp依赖性生物膜；单独的两种分子都是不够的，这表明这种表型依赖于协调两个线索。补充pABA/钙也能抑制细菌的运动。与这些表型一致的是，在含有pABA/钙的tTBS中生长的细胞富含生物膜相关基因的转录本，并预测了二胍酸环化酶，其产生第二信使环化-二- gmp （c-二- gmp）。它们还表现出c-二gmp水平升高，这是观察到的表型所必需的，因为磷酸二酯酶的过量生产取消了生物膜的形成，部分恢复了运动性。因此，这项工作提供了对促进费氏弧菌生物膜形成的条件、信号和过程的深入了解。
The marine bacterium Vibrio fischeri efficiently colonizes its symbiotic squid host, Euprymna scolopes, by producing a transient biofilm dependent on the symbiosis polysaccharide (SYP). In vitro, however, wild-type strain ES114 fails to form SYP-dependent biofilms. Instead, genetically engineered strains, such as those lacking the negative regulator BinK, have been developed to study this phenomenon. Historically, V. fischeri has been grown using LBS, a complex medium containing tryptone and yeast extract; supplementation with calcium is required to induce biofilm formation by a binK mutant. Here, through our discovery that yeast extract inhibits biofilm formation, we uncover signals and underlying mechanisms that control V. fischeri biofilm formation. In contrast to its inability to form a biofilm on unsupplemented LBS, a binK mutant formed cohesive, SYP-dependent colony biofilms on tTBS, modified LBS that lacks yeast extract. Moreover, wild-type strain ES114 became proficient to form cohesive, SYP-dependent biofilms when grown in tTBS supplemented with both calcium and the vitamin para-aminobenzoic acid (pABA); neither molecule alone was sufficient, indicating that this phenotype relies on coordinating two cues. pABA/calcium supplementation also inhibited bacterial motility. Consistent with these phenotypes, cells grown in tTBS with pABA/calcium were enriched in transcripts for biofilm-related genes and predicted diguanylate cyclases, which produce the second messenger cyclic-di-GMP (c-di-GMP). They also exhibited elevated levels of c-di-GMP, which was required for the observed phenotypes, as phosphodiesterase overproduction abrogated biofilm formation and partially rescued motility. This work thus provides insight into conditions, signals, and processes that promote biofilm formation by V. fischeri.